Seismic Hazard Risk Microzonation of Ahmedabad City

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SEISMIC HAZARD / RISK MICROZONATION OF AHMEDABAD CITY, GUJARAT

(Progress Report for the Field Season 2003-04)

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SEISMIC HAZARD / RISK MICROZONATION OF

AHMEDABAD CITY, GUJARAT (Progress Report for Field Season 2003-04)

A. K. Saxena, Geologist (Sr.)

Surendra Prasad, Geologist (Sr.)

D. N. Fulzele, Assistant Geologist

C O N T E N T

Page No.

ABSTRACT Hindi English

1. INTRODUCTION 1

Climate 2

Physiography and Drainage 2

Previous Work 3

Acknowledgement 3

2. SUBSURFACE GEOLOGY OF THE AREA 4

3. DISCUSSION ON STANDARD PENETRATION TEST (SPT) 7

4. GROUND WATER 10

5. LAND USE 13

6. SEISMOTECTONIC SETUP 16

7. SOILS 17

8. DISCUSSION ON ‘N’ VALUES 19

9. SUMMARY, CONCLUSION AND RECOMMENDATION 21

LOCALITY INDEX 23

REFERENCES 25

LIST OF ANNEXURE

I. Subsurface lithologcal log of 30 borehole 28

II. ‘N’ value of the SPT conducted in southern part of Ahmedabad city 41

III. List of Borehole drilled in Ahmedabad city for Standard Penetration Test 53

IV. Results of Analysis of Quaternary Sediments - Samples from 56 Ahmedabad City During SPT Work

PLATES

1. Depth to Ground water level map of part of Ahmedabad city, Gujarat

(D. O. No. GSI, WR, EQ, Divn./ D. O. 15/05).

2. Landuse map of Ahmedabad city and surrounding area, Gujarat (D.

O. No. GSI, WR, EQ, Divn./ D. O. 12/05).

3. Seismotectonic map of Ahmedabad city, Gujarat (D. O. No. GSI,

WR, EQ, Divn./ D. O. 14/05).

4. Soil map of part of Ahmedabad city, Gujarat (D. O. No. GSI, WR, EQ,

Divn./D.O. 13/05).

5. Map showing, SPT ‘N’ value contour map at 3.15 m depth, in parts of

Ahmedabad city, Gujarat (D. O. No. GSI, WR, EQ, Divn./ D. O.

16/05).

6. Interpreted landsat imagery map showing palaeo channel and

population density of Ahmedabad area, Gujarat (D. O. No. GSI, WR,

EQ, Divn./ D. O. 24/2006).

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SEISMIC HAZARD / RISK MICROZONATION OF

AHMEDABAD CITY, GUJARAT

A. K. Saxena, Geologist (Sr.)

Surendra Prasad, Geologist (Sr.)

D. N. Fulzele, Assistant Geologist

A B S T R A C T

During the course of seismic hazard/ risk microzonation study of

Ahmedabad city, Gujarat, seismotectonic map, ground water level map,

soil map and land use map were compiled. Besides, the Standard

Penetration Test ( SPT ) with a truck mo unted drill machine were carried

out in southern part of Ahmedabad city. The area covered during SPT

investigation falls in toposheet nos 46A/8 & 12 and 46B/5 & 9 and it

consists of fluvial and aeolian sediments of Quaternary age.

While carrying out Standard Penetration Test, a total of 30 boreholes

each up to 30 meters depth were drilled. The borehole locations were

planned at an average interval of 2.5 to 3 Km distance to cover the area

inside the Ring Road of AUDA Plan 2011(Ahmedabad Urban Development

Agency) of Ahmedabad city within the limit of proposed target of 100

boreholes. Different types of lithological units were noticed during the

course of drilling for the SPT. These units are mainly dark brown coloured

silty soil and silt, medium to coarse grained sand and clay in ascending

order. These units do not exactly occur in order of their superposition but

follow more or less same pattern of occurrence as indicated above. It has

been observed that the SPT value (i.e. ‘N’ Value) or number of blows

increases with increasing depth. Generally 7 to 30 blows were noticed

during the penetration of last 30cm of sampler ( the first 15 cm considered

as sitting) up to 12m depth but further below this value increases to more

than 50 (a refusal value). The 'N' value are by and large affected by the

compaction of sediments, the nature and intensity of kankers occurring in

the sediment and the water level occurring in the column. Many kanker

beds and alluvial fill deposits (grits, gravels and pebbles) were noticed

below 10 m depth which sometimes did not allow the auger drill to

penetrate down and the drilling operation had to be suspended. Perched

water table zones (0.5 m to 3.00m thick) were also encountered in majority

of boreholes between 5 m to 23 m depth. 99 sediment samples were

submitted to geotechnical lab for geotechnical analysis. These samples

were analysed for grain size analysis, Atterberg’s limits etc. ‘N’ value

contour map along with water level contour map were prepared.

The analysis of the SPT data and ground water level map indicate

the occurrence of an east - west trending sector which has depth to water

level less than 10m and as such is potentially susceptible to liquefaction.

The Mani Nagar area is located in the eastern part of this zone which is

also characterized by 'N' value less than 10 at SPT conducted at 3.15 to

3.45 m depth. The combination of low N value and shallow ground

water explain the greater seismic hazard potential of the Mani Nagar

area which suffered a heavy damage during by Bhuj earthquake of 26t h

January, 2001.

1. INTRODUCTION

The area under investigation consists mainly southern and partly

central part of Ahmedabad Urban Development Authority (AUDA) plan

2011 and bounded by proposed ring road (Plate. 1). The area forms a part of

Cambay rift basin and falls in Survey of India toposheet No. 46A/8, 12 and

46B/5 and 9.

Ahmedabad is one of the oldest and fast growing cit ies of India. It

was famous for textile industry in the past but recently it has again come in

limelight due to devastating Bhuj (Kachchh) earthquake of 26t h January

2001 when this disaster affected large number of human lives and damaged

numerous multistoried buildings of the city.

To minimize the socio- economic losses from the earthquake hazard

under the pre-disaster mitigation planning, the Geological Survey of India

has initiated Seismic Hazard / Risk Microzonation (SHRM) study of

Ahmedabad through its field season programme 2001-2002 with the

objective to prepare seismic hazard / risk microzonation map of Ahmedabad

city, Gujarat. The same work is being continued in the present field season

through FSP 2002-2003. Lithological and geomorphological maps of

Ahmedabad city were compiled during FS 2002-2003. During FS 2003-2004

compilation of land use map, seismo tectonic map, groundwater level map

and soil maps, mainly of southern and central part of Ahmedabad city, was

taken up, along with Standard Penetration Test (SPT) for soils.

The significant component of SHRM is standard penetration test

(SPT) which was carried out by manual operation at 8 locations upto 5 m

depth during FS 2002- 03. However, during the FS 2003-04 the Standard

Penetration Test was conducted with a truck mount ed SPT assembly at an

average interval of about 2.5 to 3 km. During the course of present work

boreholes each extending upto 30 m depth were drilled in southern and

central parts of Ahmedabad city and 99 samples of Quaternary sediments

2

were submitted for geotechnical characterization of foundation soil, which

included Atterberg Limits, Grain size analysis, moisture content and

Specific Gravity (Annexure-IV).

The results of SHRM, when completed during FS 2004-05, will

provide information on soil type vis -à- vis vulnerability of the foundation

for earthquake and classify the city areas for following specific provision of

code of construction by BIS. The scientific report after integrating

geophysical inputs including ground water data will be of immense use for

town planners and colonizers for further urbanization. It may be helpful in

colonization of the city and observing the precautionary measures to be

adopted before putting the foundation of multistoried buildings.

Climate

In general the humid climate prevails in the Ahmedabad area. The city

Ahmedabad is located not very far off from the sea, so it remains quite hot

in the summer and pleasant during the winter. Summer begins from March

and lasts upto the end of June or before monsoon sets in the area. The

southwest monsoon enters the area somewhere in the mid of June. Thus the

rainy season starts from July and continues up to September. The winter

season remains from October to February during which the days remain hot

but nights are considerably cool. In summer the temperature goes up to

about 47°C and in winter it goes down to around 4°C. The average rainfall

of the area is 635 cm.

Physiography and Drainage

The Ahmedabad city has been developed on either side of the alluvial

deposits of Sabarmati river. The area forms more or less flat land

topography with the major contour intervals at 60, 40 and 20 metres. The

study area is occupied by the sediments of Sabarmati river and aeolian

3

sands which were subsequently oxidized and pedogenised. Sometimes the

aeolian sand forms low height undulating topography.

Sabarmati river is flowing at the heart of the Ahmedabad city from

NE to SW direction with its meandering nature. Banks of the Sabarmati

towards Gandhinagar and Airport side are highly dissected with numerous

gullies and ravines. In southern side, depositional terraces have been

observed. Landsat imageries show many palaeochannels of the Sabarmati

and its shifting course from north to south (Plate 6).

Previous Work

No seismic hazard / risk microzonation work of Ahmedabad city was

ever carried out. Geological Survey of India for the first time initiated this

study in F.S. 2001 (Mathur and Saxena, 2006a, b). Geological, geo-

seismological, and geomorphological studies were carried out by Oldham

(1928), Venkatappays (1954), Taylor and Pathak (1956), Balasundaram et.

al. (1970), Das Gupta and Jain (1984), Ghevariya (1980, 81, 83), Sareen and

Bhatnagar (1984), Vijayasarthi (1984), Vijayasarthi and Sable (1984),

Radhakrishnan (1989), Sareen and Raghav (1993), Dharuman et al., (1993),

Chung (1995), Rajendra and Rajendaran (1998), Bhatia et al. (1999), Narula

et al., (2000) and Rai & Bahuguna (2001).

Acknowledgement

The authors are grateful to Dr. M. R. Kalsotra, Sr. Dy. D.G. GSI, WR

for providing logistic support to carryout the SHRM study in the

Ahmedabad area. They are also indebted to Shri R. K. Saxena, Director,

Earthquake Geology Divisio n, GSI (WR) for providing the technical

guidance, supervising the work, and scrutiny of the report.

4

2. SUB-SURFACE GEOLOGY OF THE AREA

In the FS 2003-04, total 30 boreholes (auger assembly with the SPT)

were drilled with each borehole reaching upto 30 m depth. These boreholes

intersected mainly medium to coarse grained sand, siltstone and clay with

disseminated, different sizes of kankars. Broadly the sub-surface litho-

assemblage noticed in the southern urban development area of the

Ahmedabad city are as fo llows :

Unit Nos.

Lithology Approximate depth from

surface

Age

4 Black to dark brown humus , sandy / silty soil. <3.00 m Recent

3 Silt, silty clay yellowish brown in colour with friable to hard whitish colour kankar.

3.00 m to 10.00 m or 12.00 m.

Holocene

2 Fresh, light colour, fine, medium to coarse grained sand with very hard grits, pebbles and kankars.

12.00 m to 15.00 m or 18.00 m.

-do-

1 Mainly sticky clay with sometimes alter nation of silty clay and coarse grained sand.

18.00 m to 30.00 m

-do-

Detail Description of Lithounits

Unit-4

Almost every borehole (excepting a few e.g., borehole no. AMD-12,

AMD-15 and AMD-17) exhibits / shows this lithology. Such sediments

occur between surface to about three metres depth. I t contains large amount

of humus in the upper part. It is easily identifiable in field by its typical

blackish colour. The sediments are suitable for agriculture. Grain size varies

from clay to silt to medium grained sand. It contains lot of moisture at

places. Kankar formation is poor in it. The unit shows very low ‘N’ values

(3 to 11).

5

Unit-3

This unit is gradually underlain by either silt or silty clay with friable

to compact irregular shaped kankars. The sediments are generally yellowish

brown in colour , poor ly compacted and lithified. These reflect certain

degree of oxidation and calcification. At greater depth, kankars are

observed as forming kankar bed through which the augur drill penetrates

with great difficult y. Its depth varies from 3 to 12 m from surface.

Sometimes purched water table is noticed in this zone. Normally the ‘N’

value recorded in this unit varies from 12 to 46 but in some cases it crosses

50 (i.e. the refusal value).

Unit-2

This zone contains variable sediments. The dominating sediment of

this zone are fine, medium to coarse grained sand and kankar. The lithology

is either a cleane d or whitish sand . It contains grits , pebble and kankars.

Sometimes these horizons form a thin bed. When these components are held

together with calcareous cement, they form a very hard bed. This exerts

very high resistance to auger drilling as well as SPT. The ‘N’ value noticed

in the zone varies from 46 to 111 except in borehole no. 6, 11, 12, 13 and

16. The ‘N’ values go as high as 80 to 90, even hundred plus. Sometimes,

the auger does not penetrate without pouring of additional wate r from the

top.

Unit – 1

The lower most zone in majority of boreholes is characterized by

reddish – brown sticky clay. These clay beds are generally very hard and

compact, and come out as cylindrical core. SPT shows high ‘N’ value in it.

Sometimes loose clay dark brown in colour has also been observed. Clay

6

contains kankars in form of dissemination or in thin bedded form in several

levels. ‘N’ values are very high in compact clay beds.

The zone also contains bands of silty clay, silt and coarse grained

sand occasionally and intermittently. But in most of the cases ‘N’ values are

usually high (40 to + 50 i.e. more than refusal values).

99 samples of Quaternary sediments, encountered at different depths

in the borehole s drilled for SPT, were submitted for geotechnical analysis.

The results of analysis of these samples, which include grain size analysis,

Atterberg's limit etc. are given in Annexure-IV. The majority of the

sediment samples are non-plastic. The value of moisture content does not

represent original in situ moisture of the sediment.

7

3. DISCUSSION ON STANDARD PENETRATION TEST

Auger drilling with a truck mounted machine was carried out for the

Standard Penetration Test. AW rods with a sampler of 0. 45 m length and

with a hammer of 65 kg weight have been used in carrying out the SPT.

Standard Penetration Test is the most commonly used in situ test,

especially for cohesionless soils (sand, silt) which cannot be easily sampled.

SPT is conducted in a borehole using split -spoon sampler of 0. 45 m length.

When the borehole has been drilled to the desired depth (1 m, 1.55 m and

2.55 m etc. ) the drilling tools are removed and the sampler is lowered to the

bottom of the hole. The sampler is driven into the sediments by a drop

hammer of 65 kg. weight falling through a height of 75 cm. The number of

hammer blows required to drive the sampler through 15cm of the sample /

soil sediment is counted. The same process is repeated thrice. The number

of blows recorded for the first 15 cm is disregarded or considered as sitting

value. The number of blows recorded for the last two 15 cm (i.e. total of 30

cm) intervals are added to give Standard Penetration Number (i.e. ‘N’

value).

A total of 30 boreholes were drilled upto 30 m depth (Annexure-I ) in

the central and southern part of the Ahmedabad city. The Standard

Penetration Test was conducted in each borehole at regular interval. The

recorded ‘N’ values are shown in the Annexure-I I as N R. The ‘N C’ represent

corrected ‘N’ values, in case the stratum consists of fine sand and silt,

occurs below water table and shows ‘N R’ values grea ter than 15.

Below surface , the recorded ‘N’ values (N R) are governed by the

nature of cohesion o f sediments, consolidation / compactness of the

sediment, nature and frequency of the occurrence of kankar and overburden

pressure of the sediment (i.e., depth factor). Upto a shallow depth (say 0.0

to 5.45 m) where the sediments are loosely compacted and the kankar

formation is also less, the ‘NR ’ value is 4 to 24, except in borehole no 8, 18,

8

19, 21, 24 and 25 where it is bit high, say 27 to 36. This NR value has

increased with depth. Between 5 to 10 m depth it has recorded within a

range of 14 to 50 but after 10 m depth it has gone beyond the refusal value

(i.e. 50 in nos.) with a few exceptions.

The Quaternary sediments are thick in Ahmedabad area (i.e. 400 m).

The water table is also very deep. Almost every borehole has touched the

perched ground water level at shallow depth (different depth in different

borehole, Table-1). In general in the southeastern part of AUDA, the

perched water table is noticed at shallower depth. For example it has

recorded in Chandola Talav area at 8.50 m depth, Yoshodanagar at 6 meter

depth, near Isanpur at 10.45 m depth and in Maninagar at 7.30 m depth. So

these areas are suggested as susceptible when lique faction due to earthquake

comes to an appreciable magnitude. Shallow water level has also been

recorded in Juhapura area (near Sa rkhe j) which is also equally susceptible

to lique faction. In majority of places, it occurs from 10.45 m to 20 metres

depth. At few places , it has been recorded between 23.0 m to 25.0 m depth,

for example, Kotda Dariyapur in Bapunagar area (B. No. 26) at 23.00 m

depth, Laxmipur (B. No. 19) near Lambha mandir at 22.35 m depth and

Suresh farm area (B. No. 11) at 25 m depth. In borehole nos. 20, 21, 24, 25,

29 and 30 no water level has been touched. The aforesaid water levels are

not susceptible to water discharge for drinking water, but these are

susceptible to lique faction during earth shacking, subject to other

geotechnical parameters

Distribution of Lithounits

Ahmedabad area consists of almost flat land topography occupied by

either fluvial sediments or Aeolian sediments. In most of the boreholes, the

top about 3 m sediments generally consist of sand, silty or clayey humous

soil which is often blackish or dark brown in colour, highly oxidised

containing lot of vegetal matter and remain unconsolidated (Annexure-I ).

9

This unit has been noticed in Isanpur (AMD-1), Ghorasar (AMD-2),

Yashoda Nagar (AMD-3), Sindhvai Mata area (AMD-4), Hadkeshwar

(AMD-5), Maninagar (AMD- 6 & 7), Dani limda Naral (AMD-7),

Someshwar Mahadeav (AMD- 8) , old Chandala Octroi Naka (AMD-9),

Alahanagar (AMD-10), Suresh form (AMD-11), Makarba Road Sarkhjej,

Lakshmipur (AMD-19), Odhav (AMD- 20), Sarkhej (AMD- 17 & 29),

Rakhiyal (AMD-18), Maninagar (AMD-22), Gandhigram Rly. station area

(AMD-23), Nikhola village (AMD- 24), Birat Nagar (AMD- 25), Bapunagar

(AMD-26), S ahispur Boga (AMD- 28). Some times, at somewhat higher

level, aeolian deposits form the cover sediment which has neither

pedogenised nor contains much vegetal matter. This unit is observed at

Vasna – Jahapura area (AMD-12, 13, 15), Fatehwadi (AMD- 16), southern

part of Sarkhej (AMD- 17) etc. Below this horizon, zones of silt, sand and

silty / sandy clay are met with which in majority of cases have very

nonuniform occurrence and cannot be correlated. These sediments are

generally rich in kankar (Table- 1 and Plate. 1 & 2). The next very important

unit is sticky clay, occurring generally at 12 to 15 m depth but encountered

in almost every borehole (Annexure-I ). It has reddish brown colour, is

highly compact and does contain kankars in between. This unit is very hard

and gives the ‘N’ value beyond refusal.

10

4. GROUND WATER

During the course of drilling for Standard Penetration Test (SPT)

ground water has been encountered in many boreholes at different depths

(Table-1, Plate. 1). The ground water level in different boreholes varies

from less than 1 0 m bgl to more than 20 m bgl (Table -1 ). Similarly the

thickness of aquifer zone varies from place to place. Medium to coarse

grained sand is the most common aquifer in the area. A depth to ground

water level map has been prepared (Plate-1) which shows (1) areas with

ground water occurring at less than 10 m depth (2) areas with ground water

occurring between 10 and 20 m depth and (3) areas with ground water

occurring at more than 20 m depth.

A. Areas with ground water less than 10 m depth

The area with ground water at less than 10 m depth extends in E-W

direction from west of Prakashnagar to east of Sarkhej (Plate 1). This also

includes parts of Jawahar nagar. The Kankaria Talav and Chandola Talav

are located within this zone of shallow ground water which is approximately

bisected by Sabarmati river which flows in south- westerly direction.

Another small area with ground water occurring at less than 10m occurs in

the south-eastern part of the city where Yahewa Nadi flows through it. This

smaller area of shallow ground water is separated by the main area of

shallow ground water by the zone of intermediate ground water in which the

ground water occurs between 10 m and 20 m depth.

B. Area with ground water from 10 m to 20 m depth

The area with ground water level from 10 m to 20 m also trends in

east-west direction and encompasses the zone of shallow ground water as

described above . It is wider in the eastern part and includes Jamalpura and

part of Kalupura. This zone extends in the area west of Sabarmati river

where locations like Ashok Nagar, Anand Nagar and part of Jawahar Nagar

11

are included in it. This zone tapers down in the west where it also includes

the area of Sarkhej.

C. Areas with ground water at more than 20 m depth

In many boreholes groundwater is encountered at depths exceeding 20

m. Such areas are demarcated separately as zone of deep ground water

(Plate 1). Areas with ground water level more than 20 m occur north of

Ashok Nagar, part of Kalupur and in the area around Lal Bahadur Shastri

stadium. This zone probably extends upto south of Aerodrome / Airport.

In borehole no. AMD-3, the ground water is encountered at a shallow

depth of 6 m, whereas in borehole no. AMD 19, the groundwater is

encountered at the maximum depth of 22.35 m. In a few boreholes ground

water has not been encountered upto the closing depth of borehole, i.e. 30 m

e.g. borehole no. 20, 21, 24, 25, 29 and 30 . The thickness of aquifer varies

from place to place in different boreholes. In borehole no AMD-4 and

AMD-26 the thickness of aquifer is 1 m each. In some boreholes the

thickness of aquifer increases to the order of 10 to 12 m as in borehole no

AMD-2, AMD-11 and AMD-12 (Table 1). In the aquifer zone , the N value

shows a declining trend owing to poor compaction and resistance of the

saturated sediments.

TABLE-1 : SHOWING 'N' VALUE DATA OF SPT, AND GROUND WATER LEVELS OF 30 BOREHOLES DRILLED IN SOUTHERN AND CENTRAL PARTS OF AHMEDABAD CITY, GUJARAT

Borehole → No. A

MD-

1

AM

D-2

AM

D-3

AM

D-4

AM

D-5

AM

D-6

AM

D-7

AM

D-8

AM

D-9

AM

D-1

0

AM

D-1

1

AM

D-1

2

AM

D-1

3

AM

D-1

4

AM

D-1

5

AM

D-1

6

AM

D-1

7

AM

D-1

8

AM

D-1

9

AM

D-2

0

AM

D-2

1

AM

D-2

2

AM

D-2

3

AM

D-2

4

AM

D-2

5

AM

D-2

6

AM

D-2

7

AM

D-2

8

AM

D-2

9 A

MD

-30

S. N

o.

Depth of SPT (m)

↓ 1 1.15 1.45 7 7 9 6 8 7 14 17 8 4 8 125 11 10 10 38 13 9 18 10 16 21 10 11 15 7 3 1 11 14

2 3.15 3.45 9 10 11 12 8 10 12 19 9 11 7 15 12 8 11 15 16 18 17 14 27 14 26 16 8 8 1 13 27 19

3 5.15 5.45 14 13 24 21 17 17 12 33 17 21 14 19 19 16 7 15 21 29 27 24 33 21 20 33 36 13 6 21 21 27

4 7.15 7.45 15 22 23 15 22 16 25 43 29 32 30 12 50 20 35 15 44 47 37 17 50 26 19 41 43 24 17 21 23 32

5 9.15 9.45 19 28 - 52 34 39 24 44 44 47 27 14 26 50+ 37 17 50 50+ 32 38 50+ 20 45 43 41 51 17 29 37 37

6 12.15 12.45 30 76 63 50 43 45 47 29 59 51 28 23 37 50+ 54 26 50+ 51 50+ 40 56+ 24 50+ 50 51+ 54 28 34 50

Depth to water level (mostly perched WT)

(m)

→ 10.45 17 6 18 14 14 18 18.50 9 19.25 8 8 20 14 5.30 19 16 17 22 - - 19.50 17.50 - - 23 7.3 20 - -

Thickness of aquifer

(approximately) (m)

→ 5 10-12 >4 1 4 6 2-3 7-8 5-5 5 10 10 3 5 2 5 5 1.5 & 3 1.65 - - 5 7 - - 1 3 2 - -

12

5. LAND USE

The city of Ahmedabad is a very old and unique city and is the capital

of Gujarat State and also the district headquarter. It is named after Sultan

Ahmedad Shah, who founded it in 1411 AD. It is reckoned as a great textile

and commercial centre and was known as the Manchester of India.

A landuse map (Plate-2) is prepared with the help of landsat imagery

and field checks, pertaining mainly to the area under study during the

course of drilling boreholes for SPT of the soil. Much of the city is covered

by Quaternary sediments and as such the major landuse is habitation and

industries (Plate 2) besides, agriculture / cultivation, forest, water bodies

and open grounds are also other landuse patterns. Main landuse are briefly

described below.

A. Habitation, fairely dense, mainly residential

This is the predominant landuse observed in the Ahmedabad city.

There are a number of colonies and various housing societies on either side

of the Sabarmati river. The habitation in this area is fairly dense,

concentrated and this zone is the central zone of the Ahmedabad area.

B. Habitation, generally sparse, residential cum cultivation

On the outer side of the above described zone, the outer area of

Ahmedabad city can be classified as habitation which is not as dense as the

area described above. Moreover, it is generally residential cum cultivation

in the sense that small scale cultivation of cereals, vegetables, and

horticulture are done locally. These are newly developing areas around old

and modernized villages.

13

14

C. Industries / Commercial

Large number of industries, particularly textile are located in the

Ahmedabad city since British times. The industries are located in the area

generally east of Sabarmati river in different clusters.

D. Water Bodies

Sabarmati river is like lifeline for the Ahmedabad city and it flows in

south-westerly direction. Recently, with the release of water from Narmada

canal into Sabarmati river the availability of water has improved. There are

few ponds or lakes in the city namely Chandola Talav, Kankaria lake, etc.

There are large number of small ponds scattered near villages in outer part

of the Ahmedabad city.

E. Agriculture / Cultivation and Forest

Small scale agriculture / cultivation of cereals, vegetables and flowers

(horticulture) are observed in outer parts of Ahmedabad city particularly in

the areas adjacent to Sabarmati river such as south of Jawahar nagar, south

of Sarkhej, around Lambha and similarly around other villages in the outer

part of Ahmedabad city which are also described as “Habitation, generally

sparse, residential cum cultivation” (B’ -above). The growing need of land

for housing purposes is slowly closing down the activity of cultivation as

the city is expanding in suburban areas.

F. Miscellaneous

Other important landuse in the city includes sewage farm in the south

western part, open grounds or park or fallow, roads and railways, etc. The

Ahmedabad Airport is located in the north-eastern part of the city and the

city railway station is located in the central part of the city which is known

as Kalupur area.

15

Based on geotechnical characteristics of subsurface lithologies and

the associated ‘N’ values, recommendations on landuse, particularly

suitability of foundation for various category of houses and buildings would

be discussed in the final report on Seismic Hazard / Risk Microzonation of

Ahmedabad City which would include a seismic hazard / risk microzonation

map of Ahmedabad.

An interpreted landsat imagery map showing palaeochannel and

population density of Ahmedabad area has been attempted (Plate-6). The

map shows that the interpreted palaeochannels occur in the vicinity of

Sabarmati river. Incidentally, the location of palaeochannels also coincides

with the thickly populated areas.

16

6. SEISMOTECTONIC SET UP

The seismotectonic map of Ahmedabad area (Plate-3) is based on the

Seismotectonic Atlas (Narula et al., 2000) and some other related

informations obtained from the lineament map of Gujarat. The entire

Ahmedabad area falls within the Cambay graben tectonic zone. A few

lineaments traverse through the area which trend NW-SE and NE-SW. Some

minor lineaments trending in NNW-SSE direction are also observed. The

lineaments seem to have influenced the drainage pattern in the area.

However, faults have not been encountered in the Quaternary sediments

during the course of investigation. The value of bouguer gravity is zero in

the north eastern part of the city and (+10) in the cent ral part of the city

(Plate 3) . The trend of bouguer gravity contours in the area is NW-SE. As

per the historical record two earthquakes of moderate magnitude (M- 3)

occurred in 1840 and 1843 in the eastern part of the city, beyond Ring Road

and in the area east of Vastrol.

17

7. SOILS

Different types of soils occur in Ahmedabad area (Plate-4). The map

shows lithological distribution of soils, namely, sandy soil, silty soil and

clayey soil as well as taxonomic classification of soils which is used by

agriculture scientists. The lithologica l distribution of soils is based on the

data collected during drilling 30 boreholes in the central and southern parts

of Ahmedabad city for SPT, whereas the taxonomic classification of soils is

adapted from the soil atlas prepared by the National Bureau of Soil Survey

and Landuse Planning (ICAR), 1994.

A. Lithological Distribution of Soil types :

1. Sandy soil: The sandy soil occurs along Sabarmati river as levee

deposits and over-bank deposits covering parts of Fatehpur, Jawahar nagar

and Sarkhej.

2. Silty soil: Silty soil occurs mostly in the area east of Sabarmati

river and includes localities such as Mani Nagar, Prakash N agar, parts of

Jamalpur and also in the area north and south of Lalbahadur Shastri

stadium. Kankaria and Chandola Talavs are located in th is zone.

3. Clayey soil: The clayey soil occurs mainly in the area west of

Sabarmati river. Large expanses covering Ayojan Nagar, south of

Navrangura, University area and the area north of Sarkhej are by and large

found to expose clayey soil. Clayey soil also occurs in the area west of

Chandola Talav.

B. Taxonomic Distribution of Soil types

The taxonomic distribution of soil types is used by agricultural

scientist and is adapted from the soil atl as prepared by the National Bureau

of Soil Survey and Landuse Planning (ICAR), 1994. Two types of soils are

described in the Ahmedabad area :-

18

(1) Soil along Sabarmati river on both sides :- Very deep moderately

well drained, calcareous fine loamy soil on very gently sloping flood plane

with slight erosion and slight salinity; associated with deep moderately well

drained, calcareous fine soil with slight erosion and slight salinity.

Taxonomic Nomenclature

Fine loamy, mixed (calcalreous), hyperthermic typic ustifluve nts to

fine mixed (calcareous) hyperthermic fluventic ustochrepts.

2. The second soil type in the Ahmedabad area occurs in the remaining part

of the area. This soil is deep, well- drained, fine loamy soil on very gently

sloping alluvial plane with slight erosion and slight salinity, associated with

deep, moderately well drained, calcareous, fine soil on gently sloping lands

with moderate erosion.

Taxonomic Nomenclature

Fine loamy, mixed calcalreous hyperthermic typic ustochrepts.

19

8. DISCUSSION ON ‘N’ VALUES

‘N’ values for the SPT conducted in 30 boreholes at 3.15 m to 3.45 m

depth are plotted on the map and contours are drawn in order to classify the

area and study from the point of view of geotechnical characteristic s of

foundation media (Plate- 5) . Since foundation of most of the houses and

other buildings are not required to be placed at depths greater than 3 m, the

‘N’ values around this depth provide valuable information on the

engineering properties of the foundation soil. It is clear from Table 1, that

there is wide variation in the ‘N’ values. In borehole no. AMD 5, AMD 11,

AMD 25, etc. the ‘N’ value is 7 to 8, whereas the highest ‘N’ value of 26 to

27 is observed in borehole nos. AMD 21, AMD 23 and AMD 29. Three

zones have been delineated based on the ‘N’ values (Plate 5).

A. Zone with ‘N’ Value less than 10

The zone with ‘N’ values less than 10 occurs in the area east of

Sabarmati river and extends in approximately N-S direction. In the southern

part, it partly over laps the area in which ground water is encountered at

shallow depth i.e. less than 10 m depth. This overlapping area extends from

Kankaria Talav to Cha ndola Talav and includes localities of Maninagar

where maximum damage occurred during Bhuj earthquake of Jan, 2002 and

part of Prakash Nagar where maximum damage was reported during Bhuj

earthquake of 26 Jan, 2001. This zone with ‘N’ value less than 10 overlaps

the area with ground water level between 10 to 20 m and also the area with

ground water level more than 20 m in the northern part.

This zone of ‘N’ value less than 10 is important for consideration

while placing foundation of houses, since low ‘N’ values indicate poor

compaction and may require remedial measures for stability. The sector

where this zone overlaps the area of shallow ground water (less than 10 m),

is particularly significant, since it becomes potentially susceptible to

liquefaction. The Maninagar area is located in the eastern part of this zone

20

which is characterised by shallow ground water and ‘N’ values less than 10.

The combination of low ‘N’ values and shallow ground water explain the

greater seismic hazard potential of this area which suffered heavy damage

associated with Bhuj earthquake of 26t h January 2001. Based on these

parameters we can explain the heavy damage suffered by the houses located

in Maninagar area as compared to the surrounding localities.

B. Zone with ‘N’ Values from 11 to 15

The zone with ‘N’ value 11 to 15 is spread both east and west of

Sabarmati rivers (A-5). It is (the ‘N’ value) wider in the eastern part but

narrows down in the western part around Sarkhej. This zone partly falls in

the area with ground water level at less than 10 m and partly in the area

with ground water level between 10 and 20 m.

The higher ‘N’ value in this zone indicate greater compaction of the

foundation soil and thus indicating relatively better suitability as foundation

medium.

C. Area with ‘N’ Value 16 to 20

Another area exhibiting ‘N’ value from 16 to 20 can be demarcated

mainly in the area west of Sabarmati river (Plate 5). This is subparalle l to

the trend of above described zone of ‘N’ value 11 to 15.

An undefined area with ‘N’ values more than 20 is also indicated in

the area west of Sabarmati river. The higher ‘N’ value indicates strata of

greater compaction and greater stability from the point of view of planning

foundation of houses and other buildings.

21

9. SUMMARY, CONCLUSION AND RECOMMENDATION

1. The seismic hazard / risk microzonation work of Ahmedabad city

included compilat ion of seismotectonic map, Landuse map, ground

water level map, soil map and drilling of 30 boreholes with truck

mounted auger drill machine and SPT assembly. During the

operational period the ‘N’ value (no. of blows) were noted and

Quaternary sediment samples were collected for geotechnical studies

such as grain size analysis, moisture content, void ratio attenburgs

limit, density, specific gravity and shear wave velocity.

2. During current field season programme 30 borehole upto 30 meter

depth were drilled out and Standard Penetration Test (SPT) were also

conducted at 1, 3, 5, 7, 9, 12, 15, 18, 21, 24, 27 and 30 meters depth

respectively.

3. These boreholes were drilled in southern parts of Ahmedabad city at

Isanpur, Ghorasar, Yashoda Nagar, Nikole village, Maninagar, Bapu

Nagar, Rakhiyal Char Rasta, Laxminagar, Sarkhej, Vasna, and

Memnagar areas.

4. The borehole data and SPT materials (sub-surface sediments) indicate

both cohesive soil and non- cohesive soil. The first 2 to 3 metres

consist of sandy / silty dark grey to dark brown humid soil. About 3

to 10 metres sediments consist mainly of cohe sionless silt and sand

with disseminated kankars. 10 meters below, the Quaternary

sediments consists of fresh riverine sand and sticky clay horizon.

Sometimes kankar bed, grit s and pebble beds have also been

encountered in different boreholes at variable depths .

5. During the SPT, the ground water table has been encountered at different

levels in different boreholes. These water levels are perched water level

22

type. These occur at very shallow depth i.e. 6 meters to 23 metres depth.

Some of the boreholes have not even touched the water table.

6. The SPT data reflect variable ‘N’ (no. of blows) values from surface

to the 30 m depth. In general from 1 to 5 meters the ‘N’ values are

very low i.e. 6 to below 20 but as the depth increases i.e. 5 to 15 m

depth it has gone to above 20 and below 50. In majority of cases

below 15 m depth the refusal ‘N’ values (50+) have been noticed.

7. The combination of low ‘N’ value (<10) and occurrence of ground

water at shallow depth (<10 m depth) in Maninagar area explains the

greater seismic hazard potential of this area which incidentally

suffered heavy damage due to Bhuj earthquake of 26 th Jan. 2001. The

poorly compacted and saturated sediment s were susceptible to

liquefaction resulting in collapse of houses.

8. SPT is an important tool indicating compaction of sediment s and also

nature of sediments. So another 70 boreholes are proposed for the

next year. After completion of SPT work in entire AUDA cit y of

Ahmedabad, it is expected to bring out a very clear picture of the

susceptible areas of earthquake and mitigation process to be adopted

for the city.

23

LOCALITY INDEX

Locality Longitude Latitude

Ahmedabad 72°35′00″ 23°02′30″

Alah Nagar 72°34′49′′ 22°00′06′′

Ambavadi 72°33 ′50″ 23°01 ′00″

Ashok Nagar 72°33 ′30″ 23°01 ′00″

Bapu Nagar 72°37 ′20″ 23°02 ′00″

Birat Nagar 72°38′35′′ 23°01′35′′

Chandola Talav 72°35 ′10″ 22°54 ′10″

Dani Limbda 72°34′06′′ 25°58]36′ ′

Fatehwadi 72°29′18′′ 22°58′47′′

Gandhigram Rly. Station 72°33 ′50″ 23°03 ′20″

Ghorasar 72°36 ′30″ 22°59 ′00″

Hedkeswar 72°37 ′45″ 22°59 ′35″

Isanpur 72°36 ′00″ 22°59 ′00″

Kalupur 72°36 ′00″ 22°01 ′30″

Lakshmipur 72°34′50″ 22°01′40″

Lambha 72°34 ′45″ 22°01 ′00″

Makarba 72°30′45″ 23°55′58″

Maninagar 72°36 ′00″ 22°55 ′55″

24

Locality Longitude Latitude

Memnagar 72°32′20″ 23°03′00″

Naroda 72°39′30″ 23°05′00″

Narol Chaukdi 72°35′30″ 22°58′50″

Nikhola 72°39′44′′ 23°02′13′′

Odhav 72°40′00″ 23°01′35″

Prakash Nagar 72°36′35′′ 22°59’15′ ′

Rakhiyal 72°37′09′′ 23°01′18′′

Sahispur Boga 72°38′35′′ 22°03′35′′

Sarkhej 72°30′00″ 22°59′00″

Sewage fa rm 72°34′00″ 22°59′00″

Sindhwai mata Temple 72°38′00″ 22°59′50″

Someshwar Mahadev 72°33′05′′ 22°58′54′′

Suresh Farm 72°34′18′′ 22°59′29′′

Thaltej 72°30′45″ 23°03′00″

Vallabhnagar 72°39 ′45″ 23°01 ′00″

Vasna 72°32 ′50″ 22°55′59″

Vatva 72°37′00″ 22°57′00″

Yashoda N agar 72°37′55″ 22°57′56″

25

REFERENCES

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KASLIMAL, V. K., AND SOGANI, K. C. 1970. A geological report on the

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BHATIA, S. C., RAVI KUMAR, M., and GUPTA, H.K.1999. A probabilistic

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CHUNG, W.Y. GAO, H., 1995. Source parameters of the Anjar earthquake of

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DHARU MAN, R., JOSHI, D.D. RAJ, M., WAHI, S., GUHA, D.,

CHAUDHARY, M.R., 1993. A geological report on the earthquake of August

24, 1993, off" Saurashtra coast, Gujarat.

GHEVARIYA, Z. G. 1980. Report on investigation for Bentonite deposits in Kutch

district, Gujarat. (Unpublished Rep. Geol. Sur. Ind. 1979-80)

GHEVARIYA, Z. G. 1981. Systematic geological mapping in parts of Toposheet

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GHEVARIYA, Z. G. 1983. Report on the geological mapping of Mesozeic rocks in

parts of toposheets 41 A\14, 41 E\2, 41 I\5, 41 I\9, 41 I\10 and 41 I \11 Kachchh

district Gujarat. (Unpublished Rep. Geol. Sur. Ind. 1982-83).

26

MATHUR, A. K. and SAXENA, A. K. 2006 (a). Seismic hazard / risk microzonation

of Ahmedabad city, Gujarat. (Unpublished Prog. Rept. Geol. Sur. Ind. F. S.

2001-02).

MATHUR, A. K. and SAXENA, A. K. 2006 (b). Seismic hazard / risk microzonation

of Ahmedabad city, Gujarat. (Unpublished Prog. Rept. Geol. Sur. Ind. F. S.

2002-03).

NARULA, P.L., ACHARYYA, S.K. and BANERJEE J.. 2000. Seismotectonic

Atlas of India and its Environs. Geol.Surv.Ind. Spel. Publ. No. 59.

OLDHAM, R.D., 1928. The Cutch (Kachh) earthquake of 16th June, 1819, with a

revision of the great earthquake of 12th June, 1897: Mem. Geol. Surv. Ind. Vol.

26, 1928.

RADHAKRISHNA, B.P., 1989. Suspect Tectono-stratigraphic terrane elements in

the Indian subcontinent J. Geol. Soc. India, 34, 1-24.

RAI, D.K. and BAHUGUNA, H., 2001. A Report on the Bhavnagar (Gujarat)

Earthquake Swarm between 9.8.2000 and 27.9.2000 with special reference to

12th September Earthquake. (Unpublished Repo. Geol. Surv. Ind. 2000-01).

RAJENDRAN, K. and RAJENDRAN, C.P. 1998. Characteristics of the 1997

Jabalpur earthquake and their bearing on its mechanism, Current Science, 74, p

168-174.

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VENKATAPPAYS, N., 1954. Geological report on mapping in parts of Bhachau

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1983-84).

28

Annexure-I

SUBSURFACE LITHOLOGICAL LOG OF 30 BOREHOLES

30 boreholes were drilled in the southern part of the Ahmedabad city

for Standard penetration Test. During the test the different lithologs in

auger and split sampler were noted. The subsurface lithologs of the

different borehole areas follows:

Depth range in (m) B.H. No. Locality Lithology From To

Thickness in (m)

AMD-1 Blackish silty soil 0.00 3.00

1 km east of Narol

(near Isanpur) Micaceous, light brown fine grained sand.

3.00 - 5.30 3.00

Medium to coarse grained sand 5.30 - 7.00 2.30

Medium to coarse grained sand (with numerous small kankar, mica flakes )

7.00 - 7.45 1.70

Silty sand with clay in pockets + full of whitish large kankars.

7.45 - 9.00 0.45

Silty clay with kankars large size 9.00 - 10.30 1.55

Kankar bed (did not allow drilling further)

>10.30 m depth

- 1.30

Silty clay (in SPT) with full of kankars.

10.30 - 10.60 0.30

AMD-2 Blackish silty clay (with humous) 0.00 - 1.90 1.90

South of Vatva bridge in Ghorasar area. Yellowish brown silty sand with

soft kankars. 1.90 - 5.90 3.00

Light brown silty with friable kankars.

5.90 - 7.90 2.00

Coarse grained, brown to riverine sand (lower part is loose sand)

7.90 - 15.90 8.00

Sandy clay (water level starts) 15.90 - 20.00 4.00

Sticky clay with black irregular shape. Kankars (clay is highly compact and full cores come)

20.00 - 25.90 5.90

29

Depth range in (m)

B.H. No. Locality Lithology From To Thickness

in (m)

Whitish medium grained riverine sand.

25.90 - 27.60 1.70

Compact silt + small 1-2 cm size kankars

27.60 - 30.00 2.40

AMD-3 Blackish silty soil (with humous) 0.00 - 1.60 1.60

Yashoda nagar behind Petrol pump and Apurna hotel

Fine sand with whitish kankars. 1.60 - 3.00 1.40

Yellowish coloured silty sand with kankars.

3.00 - 5.60 2.60

Whitish coarse grained sand with 3-4 cms size kankars.

5.60 - 7.00 1.40

Yellowish brown silt with sand and black coloured kankars.

7.00 - 10.90 3.90

Silt + clay slurry 10.90 - 15.15 4.25

Coarse grained sand 15.15 - 16.05 0.90

Sticky clay 16.05 - 25.00 8.95

Sandy clay. 25.00 - 25.90 0.90

Hard compact clay + kankars. 25.90 - 28.10 2.20

AMD-4 Blackish silty clay 0.00 - 2.00 2.00

Municipal corp. land in east of Sidhvai Mata Temple area

Yellowish brown coloured silty clay.

2.00 - 3.60 1.60

Medium grained sand (yellowish brown coloured) with 3-4 cmssize irregular kankars.

3.60 - 5.60 2.00

Yellowish brown silt with soft kankars

5.60 - 10.90 5.30

Kankar bed with minor sand. 10.90 - 15.30 4.40

Yellowish silt + kankars 15.30 - 15.90 0.60

Sticky clay, compact and hard. Kankar occurs frequently.

15.90 - 29.40 13.50

30

Depth range in (m)


in (m)

AMD-5 Dark brown (blackish) silty soil / silty clay.

0.00 - 3.00 3.00

Bhaipura Hedkeswar (AMC-Place)

Yellowish brown silt. 3.00 - 3.90 0.90

Yellowish brown clay 3.90 - 5.00 1.10

Silt with clay 5.00 - 5.90 0.90

Brown silt clay 5.90 - 7.30 1.40

Brownish clay 7.30 - 7.90 0.60

Fine sand 7.90 - 10.90 3.00

Sticky clay 10.90 - 20.00 9.00

Silty clay yellowish brown 20.00 - 25.90 5.90

Clay with hard kankars. 25.90 - 29.70 3.80

AMD-6 Blackish (dark brown) silty clay 0.00 - 3.00 3.00

Silt with sand 3.00 - 5.00 2.00

Silty clay yellowish coloured 5.00 - 7.30 2.30

Karnawati Apartment cooperative society, Maninagar

Clear washed fine sand with kankar

7.30 - 10.00 2.70

Yellowish brown 10.00 - 10.90 0.90

Sticky clay (clay part comes under water table in bottom side with whitish kankars)

10.90 - 29.70 18.80

AMD-7 Blackish silty clay / silty soil. 0.00 - 3.30 3.30

Brownish yellow silty clay with kankars

3.30 - 5.00 1.70

Vijay farm Sarkhej Road, Narol (Dani Limbda)

Yellowish silt with kankars 5.00 - 20.90 15.90

Clay (hard yellowish) with kankars.

20.90 - 29.70 8.80

31

Depth range in (m)


in (m)

AMD-8 Blackish (dark brown) silty clay. 0.00 - 3.30 3.30

Yellowish brown silt with fine grained sand (micaceous)

3.30 - 3.90 0.60

Coarse grained sand with kankars 3.90 - 5.90 2.00

Someshwar-Mahadeo Temple area near Subarmati bridge Narol-Surkhj highway

Medium grained sand with clay. 5.90 - 7.90 2.00

Yellowish-brown silty clay. 7.90 - 10.75 2.85

Yellowish brown sticky clay. 10.75 - 15.45 4.70

Sandy silt 15.45 - 25.15 9.70

Medium grained sand with kankars

25.15 - 28.25 3.10

AMD-9 Blackish silty soil (hunas) 0.00 - 1.00 1.00

Yellowish-brown silt / silty and with large size, irregular kankar.

1.00 - 5.00 4.00

AMC land near old Chandola octorai Naka, Narol.

Yellowish brown coarse grained sand with kankars.

5.00 - 7.00 2.00

Medium to coarse sand with rare kankar and mica flakes.

7.00 - 7.45 0.45

Sandy clay 7.45 - 9.45 2.00

Yellowish brown compact silt with kankars.

9.45 - 12.45 3.00

Sticky clay (yellowish brown) 12.45 - 18.00 5.55

Silty clay 18.00 - 18.45 0.45

Sticky clay with numerous thin kankar bad.

18.45 - 28.95 10.50

AMD-10 Blackish (dark brown) coarse to fine grained sandy silt (mica flakes)

0.00 - 3.25 3.25

In park area near ST bus stand Alahanagar .

Yellowish brown sandy silt. 3.25 - 5.45 2.20

Yellowish brown friable fine to coarse sand.

5.45 - 12.30 6.85

32


Thickness in (m)

Silty clay (yellowish brown) 12.30 - 15.25 2.95

Kankar bed 15.25 - 15.70 0.45

Compact silt 15.70 - 18.45 2.75

Silty clay (kankar) 18.45 - 24.00 5.55

Coarse grained sand whitish to yellowish-brown

24.00 - 28.50 4.50

Sandy clay. 28.50 - 28.95 0.45

AMD-11 Dark brown sandy soil 0.00 - 1.45 1.45

Dark brown sand silt. 1.45 - 5.25 3.80

Suresh Farm, west of AMC Sewerage treatment plant. East of Rajnagar Silty clay (yellowish brown)

whitish kankar 5.25 - 9.00 3.75

Yellowish brown coarse grained sand silt + mica + kankar.

9.00 - 15.00 6.00

Sand clay + kankars 15.00 - 18.00 3.00

Coarse to fine grained compact + sand + kankars.

18.00 - 21.00 3.00

Yellowish brown, unconsidated silty clay + few kankars.

21.00 - 24.00 3.00

Yellowish brown sticky clay with kankars

24.00 - 24.45 0.45

Coarse sand 24.45 - >28.50 4.05

Sticky clay. >28.50 - 28.95 +0.45

AMD-12 Fine grained sand 0.00 - 7.45 7.45

Vasna Power house, near vasna Police station Coarse grained sand (Riverine

sand) + rever kankar 7.45 - 18.00 10.55

Sticky clay (reddish brown) 18.00 - 21.45 3.45

33

Depth range in (m)


in (m)

AMD-13 Yellowish brown coloured silty clay.

0.00 - 5.45 5.45

Near Anjali cinema vasna Road near Petrol Pump. Sand with full of riverine

kankars. 5.45 - 9.00 3.55

Medium to coarse sand. 9.00 - 9.45 0.45

Very coarse grained sand with large pebbles and kankar (5 to 7 cms size)

9.45 - 12.00 2.55

Hard compact silty soil with small kankars.

12.00 - 15.45 3.45

Sticky clay+ muscovite fplaces 15.45 - 21.45 6.00

Fine sand (clearriverine sand 21.45 - 24.45 3.00

Sandy clay 24.45 - 27.80 3.35

Sand with hard kankar fragment 27.80 - 28.25 0.45

AMD-14 Blackish clay 0.00 - 3.00 3.00

Blackish clay with sand. 3.00 - 5.00 2.00

Fine washed sand 5.00 - 12.00 7.00

Bus stand Makarba road, Bakeri engineering and industry limited

Reddish brown clay compact. 12.00 - 29.00 17.00

Clay mixed with sand. 29.00 - 29.45 0.45

AMD-15 2.4 km east of Juhapura

Yellowish brown coloured fine sand

0.00 - 3.00 3.00

Medium to coarse grained sand. 3.00 - 5.00 2.00

Coarse grained sand with gravels and occasional pebbles.

5.00 - 9.00 4.00

Silty with minor kankars 9.00 - 9.45 0.45

Silty clay 9.45 - 12.30 2.85

Clay 12.30 - 15.45 2.15

Sandy clay (paste) 15.45 - 18.00 2.55

Sticky clay 18.00 - 18.45 0.45

34

Depth range in (m)


in (m)

Sandy clay with kankars 18.45 - 21.45 3.00

Clay compact 21.45 - 24.45 3.00

Sandy clay clay with very hard kankars (drilling abandoned)

24.45 - 29.75 5.25

AMD-16 About 800 m west of Sarkhaj Rly. Station.

Light yellowish clayey soil (dusty in nature) in lower part + kankar occurs.

0.00 - 3.00 3.00

Yellowish brown silt 3.00 - 5.45 2.45

Silty clay (micaceous) (dark brown in colour)

5.45 - 7.00 1.55

Sandy silt 7.00 - 7.45 0.45

Clay 7.45 - 12.00 4.55

Compact silty clay 12.00 - 15.45 3.45

Medium grained friable sand with kankars. Fluvial coarse grained sand. Some times gravels in lower part.

15.45 - 21.45 6.00

Water saturated fine sand 21.45 - 24.55 3.00

Sticky clay. 24.55 - 30.45 6.00

AMD-17 Yellowish brown clay 0.00 - 1.00 1.00

Back side of the ITI Nawal Fateh wadi Indranagar Surkheej

Clay, silt and kankars 1.00 - 3.45 2.45

Brownish clay 3.45 - 5.30 1.85

Silt 5.30 - 5.45 0.15

Blackish clay 5.45 - 7.10 1.65

Fine grained sand with kankars 7.10 - 9.17 9.07

Kankar bed 9.17 - 9.45 0.28

Calcrete Pan 9.45 - 12.00 2.55

Clay whitish dark brown 12.00 - 15.00 3.00

35


Thickness in (m)

Silt + clay 15.00 - 15.45 0.45

Fine to medium grained sand 15.45 - 18.00 2.55

Medium to coarse grained sand with rarely pebbles (water saturated)

18.00 - 21.00 3.00

Fine to medium grained sand with gravels.

21.00 - 27.00 6.00

Medium to coarse grained sand with blackish grits and gravels (river bed like sediments)

27.00 - 27.45 0.45

Fine to medium sand 27.45 - 30.00 2.55

Compact clay + blackish grits 30.00 - 30.45 +0.45

AMD-18 Dark brown silty soil. 0.00 - 3.30 3.30

Pale yellow coloured silt with minor kankars.

3.30 - 5.45 2.15

Half a km west of Rakhiyal char rasta, in the campus of Neptune spin mill

Fine grained sand 5.45 - 9.26 3.81

Yellowish brown silt (compact silt + kankar in lower part)

9.26 - 21.00 11.74

Reddish yellow fine grained sand with kankars.

21.00 - 24.10 3.10

Pale yellowish clay 24.10 - 27.12 3.02

Coarse to very coarse grained sand

27.12 - 30.30 2.18

AMD-19 Black clay soil (sticky) 0.00 - 3.00 3.00

Laxmipur near Lambha mandir

Silty clay 3.00 - 5.24 2.24


Silty clay 7.25 - 12.45 5.00

Clay silty brownish 12.45 - 15.45 3.00

Clay part 15.45 - 18.00 2.55

Silty clay 18.00 - 21.45 3.45


Clay silty mixture 24.45 - 30.30 5.85

Fine grained sand 30.30 - 30.45 +0.15

36

Depth range in (m) B.H. No. Locality Lithology From To Thickness

in (m) AMD-20 Black clay soil 0.00 - 3.11 3.11


Suraj Socieyt (Swanil Park Gdhav Jagdambika Nagar

Silty clay with kankars 5.35 - 7.16 1.81

Fine sand with kankar 7.16 - 7.45 0.29

Pale silty clay 7.45 - 9.10 2.65

Silty clay 9.10 - 12.11 3.01

Fine to medium grained sand with clay in pockets

12.11 - 15.45 3.34

Silty sand 15.45 - 18.00 2.55

Coarse grained whitish sand with grits and pebbles (dry friable nature)

18.00 - 21.27 3.27

Reddish brown compact clay 21.27 - 24.45 3.18

Gritty sand 24.45 - 26.45 2.00

Reddish brown compact clay 26.45 - 27.00 0.55

Coarse grained sand with grits and pebbles like river bed

27.00 - 30.00 3.00

Grey silt. 30.00 - 30.45 +0.45

AMD-21 Yellowish brown sandy clay dust 0.00 - 0.50 0.50

Blackish (dark brown) silty clay 0.50 - 1.45 0.95

Yellowish brown silt + small kankars.

1.45 - 5.45 4.00

Ahmedabad textile and research institute; Ambavadi 2 km south of parimal Garden

Yellowish brown fine grained sand

5.45 -- 9.00 3.55

Medium to fine grained sand (yellowish brown0, kankar.

9.00 - 15.37 6.37

Very coarse grained sand with grits

15.37 - 15.42 0.05

Yellowish brown clay 15.42 - 18.21 2.79

Silty clay 18.21 - 24.45 6.24

Fine grained grey colour sand 24.45 - 27.45 3.00

Kankar bed. 27.45 - 30.00 2.55

37


in (m) AMD-22 Blackish clay soil 0.00 - 1.45 1.45

Yellowish brown soil 1.45 - 3.00 1.55

Clay with CO3 patches 3.00 - 3.45 0.45

Shri Raman maharshi Kendra, Driving road crurkal Maninagar


Clay yellowish brown 7.05 - 9.10 2.05

Silty clay 9.10 - 15.00 5.90

Kankar formation with silty clay 15.00 - 21.36 6.36

Reddish brown clay + kankar 21.36 - 30.00 8.64

Kankar bed with minor silt 30.00 - 30.45 +0.45

AMD-23 Dark brown silty clay 0.00 - 1.45 1.45


MB Foundation campus, near Gandhi gram Railway Station

Fine grained yellowish sand 3.45 - 5.00 1.55

Yellowish silt 5.00 - 7.00 2.00

Very coarse grained sand with grits and pebbles.

7.00 - 12.00 5.00

Coarse grained sand gradually turns into silt

12.00 - 14.45 0.45

Silty clay 14.45 - 15.45 3.00

Dark yellowish sandy clay 15.45 - 21.00 5.55

Reddish yellow fine grained sand 21.00 - 24.45 3.55

Very-very hard kankar pan 24.45 - 26.80 2.35

AMD-24 Dark brown silty soil 0.00 - 3.20 3.20

Sandy silt 3.20 - 5.00 1.80

Nikhola, stat dispensary (Panchayat Samitee)

Fine sandy silt 5.00 - 5.45 0.45

Coarse to fine sand with kankars 5.45 - 7.32 1.87

Silt with kankars 7.32 - 9.45 2.13

Silty clay 9.45 - 15.00 5.55

Yellowish silt with minor kankars 15.00 - 15.45 0.45

38


Thickness in (m)

Sticky clay (reddish brown) 15.45 - 24.00 8.55

Yellowish brown silty clay 24.00 - 27.00 3.00

Fine sand reddish yellow 27.00 - 30.00 3.00

Clean sand medium to coarse grained.

30.00 - 30.45 0.45

AMD-25 Black silty soil 0.00 - 3.06 3.06

Yellowish coloured silty / fine sandy silt

3.06 - 5.28 2.22

AM (Part Birat nagar west of Thakar Nagar)

Kankar bed 5.28 - 5.45 0.17

Yellowish brown silt with minor kankars

5.45 - 9.14 3.69

Whitish / cleaned medium to fine grained sand.

9.14 - 11.00 1.86


Reddish brown silty clay 15.12 - 15.45 0.33

Reddish brown (sticky) clay 15.45 - 21.45 6.00

Silty / sand clay 21.45 - 24.32 2.87

Coarse grained sand 24.32 - 25.00 0.68

Clay bed 25.00 - 26.00 1.00

Coarse sand with grits and gravel 26.00 - 27.00 1.00

Very coarse grained sand with grits and gravel (forming a hard kankar bed)

27.00 - 27.45 0.45

Silty clay 27.45 - 29.80 2.34

Gritty bed 29.80 - 29.95 +or >0.50

AMD-26 Black silty soil 0.00 - 3.12 3.12

Yellowish brown silt, silt with kankars

3.12 - 9.00 5.88

AMC area Dariyapur, Bapu Nagar Near Home Guard office

Silty clay / silt 9.00 - 12.45 3.45

Reddish brown clay (sticky clay) 12.45 - 15.45 3.00

39


in (m) Reddish brown silty clay 15.45 - 18.00 2.55

Compact reddish – brown clay (hard)

18.00 - 21.00 3.00


Reddish brown clay with kankars 24.00 - 30.45 6.45+

AMD-27 Kankaria Dedki nagar, Nursery, maninagar

Dark-grey blackish coloured silty soil

0.00 - 5.00 5.00

Dark grey clay 5.00 - 7.00 2.00

Sandy clay 7.00 - 9.00 2.00

Clayey sand 9.00 - 12.00 3.00

Clayey silt 12.00 - 15.00 3.00

Silty with kankars 15.00 - 18.00 3.00

Clay silt + mica flacks 18.00 - 27.00 9.00


Silty clay with kankars 30.00 - 30.45 0.45 +

AMD-28 Blackish silty soil. 0.00 - 1.45 1.45

Silt 1.45 - 3.45 2.00

Fine sand / coarse grained sand. 3.45 - 7.45 4.00

Excise chowki AMC Plot : Dayabhi Mukhine chali, Sahispur Boga, Naroda Road

Yellowish fine grained sand with kankars and pebbles

7.45 - 9.45 2.00

Clayey silt with kankars 9.45 - 13.45 4.00

Silt 13.45 - 15.45 2.00

Dark brown clay, (compact) 15.45 - 27.00 11.55

Fine grained sand with pebbles 27.00 - 30.40 3.00

Compact clay with hard kankar bed.

30.40 - 30.45 0.045+

40


Thickness in (m)

AMD-29 Dark brown (blackish) silty soil. 0.00 - 3.00 3.00

Clay with hard kankar 3.00 - 5.00 2.00

Bapa bhai ka plot, Back of Niki Fort car shop Sarkhaj- Jodhpur highway

Dark brown silty with mica flacks 5.00 - 9.20 4.20

Fine grained sand. 9.20 - 18.00 8.80

Silty clay with kankars 18.00 - 18.45 0.45


Coarse grained riverine sand with pebbles / kankars

24.30 - 30.00 6.00

Compact clay with kankars 30.00 - 30.45 0.45+

AMD-30 Dark brown silty soil. 0.00 - 1.45 1.45


Yellowish brown coloured clay, micaceous.

3.00 - 9.00 6.00

Makarba village back side of Divya Bhoskar press, Gandhi highway

Sandy clay (reddish brown in colour)

9.00 - 12.25 3.25

Kankar bed 12.25 - 12.45 0.20

Clay silt with kankar 12.45 - 15.45 3.00


Clay 18.25 - 18.45 0.20

Medium grained sand with very hard kankar bed

18.45 - 21.45 3.00

Kankar bed 21.45 - 24.20 2.75

Clay / clay silt with hard kankar 24.20 - 30.45 6.25

Annexure-II

BoreholeNo. Depth (m) From To NR Nc

AMD-1 1.45 1.15 1.45 7 171.10

3.45 3.15 3.45 9 181.70

5.45 5.15 5.45 14 208.20

7.45 7.15 7.45 15 213.50

9.45 9.15 9.45 19 234.70

10.45 10.45 10.75 30 293.00 0.3 3.2 217.0333

AMD-2 1.45 1.15 1.45 7 171.10

3.45 3.15 3.45 10 187.00

5.45 5.15 5.45 13 202.90

7.45 7.15 7.45 22 250.60

9.45 9.15 9.45 28 282.40

15.45 15.15 10.45 76 399.00

20.45 20.15 20.45 53 399.00

25.45 25.15 25.45 77 399.00

27.75 27.45 27.75 72 43 399.00 0.32 3.07 227.7

AMD-3 1.45 1.15 1.45 9 181.70

3.45 3.15 3.45 11 192.30

5.45 5.15 5.45 24 261.20

7.45 7.15 7.45 23 19 255.90

9.45 9.15 9.45 54 34 399.00

20.45 20.15 20.45 65 399.00

25.45 25.15 25.45 72 399.00

27.65 27.35 27.65 46 377.80 0.45 2.2 2.2

AMD-4 1.45 1.15 1.45 6 165.80

3.45 3.15 3.45 12 197.60

5.45 5.15 5.45 21 245.00

7.45 7.15 7.45 15 213.50

N value of the SPT conducted in southern part of Ahmedabad cityN-value Vs = 5.3 n

+134g

gravityAmpli-fication

Average ofVs

41



+134g


Average ofVs

10.45 10.15 10.45 53 399.00

15.45 15.15 15.45 100 399.00

20.45 20.15 20.45 54 399.00

25.45 25.15 25.45 64 399.00

27.80 27.65 27.80 71 399.00 0.44 2.23 313.02

AMD-5 1.45 1.15 1.45 8 176.40

3.45 3.15 3.45 8 176.40

5.45 5.15 5.45 17 224.10

7.45 7.15 7.45 22 250.80

10.45 10.15 10.45 34 314.20

15.45 15.15 15.45 43 361.90

20.45 20.15 20.45 58 399.00

25.45 25.15 25.45 62 399.00

28.25 27.95 28.25 15 213.50 0.99 2.5 279.4

AMD-6 1.45 1.15 1.45 7 171.10

3.45 3.15 3.45 10 187.00

5.45 5.15 5.45 17 224.10

7.45 7.15 7.45 16 218.80

10.45 10.15 10.45 39 340.70

15.45 15.15 15.45 46 377.80

20.45 20.15 20.45 22 250.60

25.45 25.15 25.45 65 399.00

28.25 27.95 28.25 77 399.00 0.4 2.4 285.3

AMD-7 1.45 1.15 1.45 14 208.20

3.45 3.15 3.45 12 197.60

5.45 5.15 5.45 12 197.60

7.45 7.15 7.45 25 266.50

42



+134g


Average ofVs

10.45 10.15 10.45 24 261.20

15.45 15.15 15.45 47 383.10

20.45 20.15 20.45 53 399.00

25.45 25.15 25.45 67 399.00

28.25 27.95 28.25 84 399.00 0.43 2.32 301.2

AMD-8 1.45 1.15 1.45 17 224.10

3.45 3.15 3.45 19 234.70

5.45 5.15 5.45 33 298.90

7.45 7.15 7.45 43 361.90

10.45 10.15 10.45 44 367.20

15.45 15.15 15.45 29 22 287.70

20.45 20.15 20.45 27 21 277.10

25.45 25.15 25.45 33 24 298.90

28.25 27.95 28.25 62 38 399.00 0.43 2.29 305.5

AMD-9 1.45 1.15 1.45 8 176.40

3.45 3.15 3.45 9 181.70

5.45 5.15 5.45 17 224.10

7.45 7.15 7.45 29 287.70

9.45 9.15 9.45 44 30 367.20

12.45 12.15 12.45 60 37 399.00

15.45 15.15 15.45 67 399.00

18.45 18.15 18.45 66 399.00

21.45 21.15 21.45 59 399.00

24.45 24.15 50.00 50 399.00

28.95 28.65 28.95 50 399.00 0.47 2.12 330.1

AMD-10 1.45 1.15 1.45 4 155.20

3.45 3.15 3.45 11 192.00

43



+134g


Average ofVs

5.45 5.15 5.45 21 245.30

7.45 7.15 7.45 32 303.60

9.45 9.15 9.45 47 383.10

12.45 12.15 12.45 52 399.00

15.45 15.15 15.45 112 399.00

18.45 18.15 18.45 59 399.00

21.45 21.15 21.45 29 287.70

24.45 24.15 24.45 94 55 399.00

25.45 25.15 25.45 96 55 399.00

28.95 28.65 28.95 81 399.00 0.42 2.36 296.8

AMD-11 1.45 1.15 1.45 4 155.20

3.45 3.15 3.45 7 171.10

5.45 5.15 5.45 14 208.20

7.45 7.15 7.45 30 293.00

9.45 9.15 9.45 27 21 277.10

12.45 12.15 12.45 28 22 282.40

15.45 15.15 15.45 39 340.70

18.45 18.15 18.45 38 27 335.40

21.45 21.15 21.45 72 399.00

24.45 24.15 24.45 55 35 399.00

28.95 28.65 28.95 97 399.00 0.42 2.36 296.3

AMD-12 1.45 1.15 1.45 12 197.60

3.45 3.15 3.45 15 213.50

5.45 5.15 5.45 19 234.70

7.45 7.15 7.45 12 197.60

9.45 9.15 9.45 14 208.20

12.45 12.15 12.45 23 19 255.90

44



+134g


Average ofVs

15.45 15.15 15.45 31 23 298.30 0.35 2.79 250.6

18.45 18.15 18.45 78 399.00

AMD-13 1.45 1.15 1.45 11 192.30

3.45 3.15 3.45 12 197.60

5.45 5.15 5.45 19 234.70

7.45 7.15 7.45 50 399.00

9.45 9.15 9.45 26 271.80

12.45 12.15 12.45 37 330.10

15.45 15.15 15.45 26 271.80

18.45 18.15 18.45 40 346.00

21.45 21.15 21.45 35 25 319.50 0.43 2.29 305.5

24.45 24.15 24.45 53 34 399.00

28.95 27.65 28.95 50 33 399.00

AMD-14 1.45 1.15 1.45 10 187.00

3.45 3.15 3.45 8 176.40

5.45 5.15 5.45 16 218.80

7.45 7.15 7.45 20 240.00

9.45 9.15 9.45 76 399.00

12.45 12.15 12.45 68 399.00

15.45 15.15 15.45 47 387.10

18.45 18.15 18.45 54 399.00

21.45 21.15 21.45 86 399.00

24.45 24.15 24.45 85 399.00 0.46 2.14 327.2

29.15 29.00 29.15 110 399.00

AMD-15 1.45 1.15 1.45 10 187.00

3.45 3.15 3.45 11 192.30

5.45 5.15 5.45 7 171.10

45



+134g


Average ofVs

7.45 7.15 7.45 35 25 315.50

9.45 9.15 9.45 37 26 330.10

12.45 12.15 12.45 54 399.00

15.45 15.15 15.45 62 399.00

18.45 18.15 18.45 43 361.90

21.45 21.15 21.45 70 399.00

24.45 24.15 24.45 62 399.00 0.42 2.3 296

27.45 27.15 27.45 62 399.00

29.60 29.45 29.60 50 399.00

AMD-16 1.45 1.15 1.45 38 335.10

3.45 3.15 3.45 15 213.50

5.45 5.15 5.45 15 213.50

7.45 7.15 7.45 15 213.50

9.45 9.15 9.45 17 224.10

12.45 12.15 12.45 26 271.80

15.45 15.15 15.45 41 351.30

18.45 18.15 18.45 50 399.00

21.45 21.15 21.45 13 202.90 0.34 2.39 393

24.45 24.15 24.45 66 40 399.00

30.45 30.15 30.45 58 399.00

AMD-17 1.45 1.15 1.45 13 202.90

3.45 3.15 3.45 16 218.80

5.45 5.15 5.45 21 245.30

7.45 7.15 7.45 44 367.20

9.45 9.15 9.45 70 399.00

12.45 12.15 12.45 50 399.00

15.45 15.15 15.45 50 399.00

46



+134g


Average ofVs

18.45 18.15 18.45 27 277.10

21.45 21.15 21.45 38 399.00

24.45 24.15 24.45 52 399.00

27.45 27.15 27.45 50 399.00

30.45 30.15 30.45 50 399.00

AMD-18 1.45 1.15 1.45 9 181.70

3.45 3.15 3.45 18 229.40

5.45 5.15 5.45 29 287.70

7.45 7.15 7.45 47 383.10

9.45 9.15 9.45 60 399.00

12.45 12.15 12.45 51 399.00

15.45 15.15 15.45 55 399.00

18.45 18.15 18.45 66 40 399.00

21.45 21.15 21.45 50 33 399.00

24.45 24.15 24.45 48 32 388.40

27.45 27.15 27.45 50 33 399.00

30.45 30.15 30.45 85 399.00 0.5 1.97 355.2

AMD-19 1.45 1.15 1.45 18 229.40

3.45 3.15 3.45 15 213.50

5.45 5.15 5.45 27 277.10

7.45 7.15 7.45 37 330.10

9.45 9.15 9.45 32 303.60

12.45 12.15 12.45 79 399.00

15.45 15.15 15.45 74 399.00

18.45 18.15 18.45 50 399.00

21.45 21.15 21.45 51 399.00

24.45 24.15 24.45 66 40 399.00

47



+134g


Average ofVs

27.45 27.15 27.45 89 399.00

30.45 30.15 30.45 89 52 399.00 0.49 2.02 345.5

AMD-20 1.45 1.15 1.45 10 187.00

3.45 3.15 3.45 14 208.20

5.45 5.15 5.45 24 261.20

7.45 7.15 7.45 17 224.10

9.45 9.15 9.45 38 335.40

12.45 12.15 12.45 40 346.00 0.46 2.16 323.3

15.45 15.15 15.45 55 399.00

18.45 18.15 18.45 50 399.00

24.45 24.15 24.45 50 399.00

27.45 27.15 27.45 50 399.00

30.45 30.15 30.45 50 399.00

AMD-21 1.45 1.15 1.45 16 218.80

3.45 3.15 3.45 27 277.10

5.45 5.15 5.45 33 298.90

7.45 7.15 7.45 50 399.00

9.45 9.15 9.45 55 399.00

12.45 12.15 12.45 66 399.00

15.45 15.15 15.45 64 399.00

18.45 18.15 18.45 36 324.80

21.45 21.15 21.45 50 399.00

24.45 24.15 24.45 50 399.00

27.45 27.15 27.45 50 399.00 0.5 1.97 355

30.45 30.15 30.45 51

AMD-22 1.45 1.15 1.45 21 245.30

3.45 3.15 3.45 14 208.20

48



+134g


Average ofVs

5.45 5.15 5.45 21 245.30

7.45 7.15 7.45 26 271.80

9.45 9.15 9.45 20 240.00

12.45 12.15 12.45 24 261.20

15.45 15.15 15.45 63 399.00

18.45 18.15 18.45 54 399.00

21.45 21.15 21.45 54 399.00 0.45 2.17 322.1

24.45 24.15 24.45 54 399.00

27.45 27.15 27.45 50 399.00

30.45 30.15 30.45 50 399.00

AMD-23 1.45 1.15 1.45 10 187.00

3.45 3.15 3.45 26 271.80

5.45 5.15 5.45 20 240.00

7.45 7.15 7.45 19 234.70

9.45 9.15 9.45 45 372.50

12.45 12.15 12.45 54 399.00

15.45 15.15 15.45 50 399.00

18.45 18.15 18.45 35 319.50

21.45 21.15 21.45 24 20 261.20 0.45 2.21 316.6

24.45 24.15 24.45 50 33 399.00

26.65 26.50 26.65 50 399.00

AMD-24 1.45 1.15 1.45 11 192.30

3.45 3.15 3.45 16 218.80

5.45 5.15 5.45 33 298.90

7.45 7.15 7.45 41 351.30

9.45 9.15 9.45 43 361.90

12.45 12.15 12.45 50 399.00

49



+134g


Average ofVs

15.45 15.15 15.45 43 361.90

18.45 18.15 18.45 50 399.00

21.45 21.15 21.45 55 399.00

24.45 24.15 24.45 53 399.00

27.45 27.15 27.45 52 399.00

30.30 30.15 30.30 50 399.00

AMD-25 1.45 1.15 1.45 15 213.50

3.45 3.15 3.45 8 176.40

5.45 5.15 5.45 36 324.80

7.45 7.15 7.45 43 361.90

9.45 9.15 9.45 41 351.30

12.45 12.15 12.45 51 399.00

15.45 15.15 15.45 50 399.00

18.45 18.15 18.45 61 399.00

21.45 21.15 21.45 41 351.30

24.45 24.15 24.45 47 383.10

27.45 27.15 27.45 78 399.00

29.95 29.65 29.95 51 399.00

AMD-26 1.45 1.15 1.45 7 171.10

3.45 3.15 3.45 8 176.40

5.45 5.15 5.45 13 202.90

7.45 7.15 7.45 24 261.20

9.45 9.15 9.45 51 399.00

12.45 12.15 12.45 52 399.00

15.45 15.15 15.45 67 399.00

18.45 18.15 18.45 38 335.40

21.45 21.15 21.45 80 399.00

50



+134g


Average ofVs

24.45 24.15 24.45 83 399.00

27.45 27.15 27.45 50 399.00

30.45 30.15 30.45 55 399.00 0.46 2.13 328.3

AMD-27 1.45 1.15 1.45 3 149.90

3.45 3.15 3.45 1 139.30

5.45 5.15 5.45 6 165.80

7.45 7.15 7.45 17 224.10

9.45 9.15 9.45 17 15 224.10

12.45 12.15 12.45 54 34 399.00

15.45 15.15 15.45 47 32 383.10 0.46 2.28 306.6

18.45 18.15 18.45 58 36 399.00

21.45 21.15 21.45 50 33 399.00

24.45 24.15 24.45 50 33 399.00

27.15 27.00 27.45 55 35 399.00

30.30 30.15 30.30 50 399.00

AMD-28 1.45 1.15 1.45 4 155.20

3.45 3.15 3.45 13 202.90

5.45 5.15 5.45 21 245.30

7.45 7.15 7.45 21 245.30

9.45 9.15 9.45 29 287.70

12.45 12.15 12.45 48 388.40

15.45 15.15 15.45 55 399.00

18.45 18.15 18.45 55 399.00

21.45 21.15 21.45 32 303.60 0.44 2.24 312.8

24.45 24.15 24.45 37 330.10

27.45 27.15 27.45 50 33 399.00

30.45 30.15 30.45 50 33 399.00

51



+134g


Average ofVs

AMD-29 1.45 1.15 1.45 11 192.30

3.45 3.15 3.45 27 277.10

5.45 5.15 5.45 21 245.30

7.45 7.15 7.45 23 255.90

9.45 9.15 9.45 37 330.10

12.45 12.15 12.45 34 314.20 0.45 2.2 317.2

15.45 15.15 15.45 18 229.40

18.45 18.15 18.45 65 399.00

21.45 21.15 21.45 44 367.20

24.45 24.15 24.45 50 399.00

27.45 27.15 27.45 50 399.00

30.15 30.00 30.15 50 399.00

AMD-30 1.45 1.15 1.45 14 208.20

3.45 3.15 3.45 19 237.70

5.45 5.15 5.45 27 277.10

7.45 7.15 7.45 32 303.60

9.45 9.15 9.45 37 330.10

12.45 12.15 12.45 50 399.00

15.45 15.15 15.45 50 399.00

18.45 18.15 18.45 45 372.50

21.45 21.15 21.45 50 399.00

24.45 24.15 24.45 50 399.00

27.45 27.15 27.45 50 399.00 0.48 2.07 338.2

52

Annexure-III

S. No.

Borehole No. Location Lat. Long. GW (m)

Date of commencement

& completion1 AMD-1 Between narol on Isanpur chaukdi 22°58’26” 72°35’35” 10.45 19.12.02

20.12.03

2 AMD-2 1/2 kmm east of Isanpur char Rastaand Before Vatva bridge (Ghorasararea)

22°58’41” 72°36’40” 18 22.12.0325.12.03

3 AMD-3 Yashodo nagar Back of Petrol pumpand & south of Permeswar society

22°58’58” 72°37’55” 6 27.12.0330.12.03

4 AMD-4 AMC land, 300 m away fromSindhai mata temple.

22°59’21” 72°38’15” 17.05 31.12.0303.01.04

5 AMD-5 Bhaipura Hedkeswar area AMCland.

22°59'35" 72°37'45" 14 05.01.0407.01.04

6 AMD-6 Karnawati Apartment cooperativesociety, Maninagar

22°59'15" 72°36'35" 14 08.01.0411.01.04

7 AMD-7 Vijay Form Sarkhej Narol (DaniLimbda)

22°58’36” 72°34’06” 18 12.01.04

8 AMD-8 Someshwar-Mahadeo area sarkhejhighway, before bridge.

22°58’54” 72°33’05” 18.5 17.01.0419.01.04

9 AMD-9 AMC land near old Chandola octoraiNaka

22°58’54” 72°35’05” 8.5 27.01.0428.01.04

10 AMD-10 Park site, near ST-Bus workshop,Alahnagar

22°00’06” 72°34’49” 19.25 29.01.0401.02.04

11 AMD-11 Suresh Form, Infront of MC plant, inwest of Chimni

22°59’29” 72°34’18” 25 03.02.04

List of Boreholes Drilled in Southern and Central Parts of Ahmedabad City for Standard Penetration Test

53

S. No.



& completion12 AMD-12 Vasna Power house, near vasna

Police station22°59’49” 72°32’47” 8 05.02.04

07.02.04

13 AMD-13 Anjali cinema vasna road nearPetrol Pump.

23°00’20” 72°33’07” 20 08.02.0410.02.04

14 AMD-14 Vedalpur Bus stand Makarba road,Bakeri engineering and industrylimited

23°00'00" 72°30'30" 14 11.02.0414.02.04

15 AMD-15 2.4 km east of Juhapura, near NH-8& bypass

22°59’40” 72°32’00” 5.3 16.02.04

16 AMD-16 Fatehwadi back of Gopal hotel ipeselling corporate

22°58’47” 72°29’18” 19 19.02.0421.02.04

17 AMD-17 Backside of the ITI NawabFatehwadi, Indranagar

22°58’28” 72°30’12” 16 23.02.0425.02.04

18 AMD-18 Half a km west of Rakhiyal charrasta, Neptune spin Fab. Limited

23°01’18” 72°37’09” 17 26.02.0428.02.04

19 AMD-19 Laxmipur Near Lambha Mandir 22°56’34” 72°34’28” 22 17.03.0419.03.04

20 AMD-20 Suraj Socieyt (Swanil Park) odhawJagdambika Nagar

23°01’45” 72°39’11” Not touched 22.03.04

21 AMD-21 Ahmedabad textile and researchinstitute; Ambavadi 2 km south ofparimal Garden

23°01’51” 72°32’34” Not touched 25.03.0427.03.04

22 AMD-22 Shri Raman maharshi Kendra,Driving road crurkal Meninagar

23°02’43” 72°31’56” 19.5 29.03.0431.03.04

23 AMD-23 MB Foundation campus, nearGandhi grum Railway Station

23°01’32” 72°34’14” 17.5 01.04.0403.04.04

54

S. No.



& completion24 AMD-24 Nikhola, stat dispensary (Panchayat

Samitee)23°02’13” 72°39’44” Not touched 05.04.04

07.04.04

25 AMD-25 MC Park Birat nagar west of ThakarNagar

23°01’35” 72°38’35” Not touched 08.04.04

26 AMD-26 AMC area Dariyapur, Bapu NagarNear Home Guard office

23°02’46” 72°37’40” 23 15.04.0418.04.04

27 AMD-27 Kankaria Dedki nagar, Nursery,maninagar

23°00’42” 72°36’42” 7.3 19.04.0421.04.04

28 AMD-28 AMC Plot : Dayabhi Mukhine chali,Sahispur Boga, Naroda Roadexcise chauki

23°03'35" 72°38'35" 20 22.04.0424.04.04

29 AMD-29 Bapa bhai ka plot, Back of Niki Fortcar shop Sarkha- Jodhpur highway

23°01'10" 72°29'30" Not touched 26.04.0428.04.04

30 AMD-30 Makarba village back side of DivyaBhoskar press, Gandhi Nagarhighway

23°59’57” 72°30’08” Not touched 29.04.0401.05.04

55

Annexure-IV

S. Sample Depth Moisture Sp.No. No. (m) content

(%)Gravel

(%)Sand (%)

Silt+Clay(%)

Gr. LL(%)

PL(%)

PI(%)

1 AMD-1/2 1.30 7.7 69.61 30.39 19.3

2 AMD-1/3 1.75 6.5 80.47 19.53 Non-plastic

3 AMD-1/5 3.30 4.6 84.36 15.64 Non-plastic

4 AMD-1/7 3.90 3.4 93.69 6.31 Non-plastic

5 AMD-1/9 5.75 8.2 88.78 11.22 Non-plastic

6 AMD-1/11 7.30 4.3 75.85 24.15 Non-plastic

7 AMD-1/12 7.75 4.4 61.04 38.96 Non-plastic

8 AMD-1/14 9.30 12.8 56.40 43.60 19.9

9 AMD-1/15 9.75 7.1 56.88 43.12 Non-plastic

10 AMD-1/17 10.45 11.9 59.45 40.55 19.6

11 AMD-2/1 1.00 5.0 74.11 25.89 Non-plastic

12 AMD-2/2 1.30 5.0 72.67 27.33 Non-plastic

13 AMD-2/3 1.60 5.4 76.83 23.17 Non-plastic

14 AMD-2/4 3.00 4.3 76.79 23.21 Non-plastic

15 AMD-2/5 3.30 4.1 80.74 19.26 Non-plastic

16 AMD-2/6 3.60 5.9 67.53 32.47 Non-plastic

17 AMD-2/7 5.00 6.8 75.38 24.62 Non-plastic

18 AMD-2/8 5.30 6.0 67.48 32.52 Non-plastic

19 AMD-2/9 5.60 5.8 78.17 21.83 Non-plastic

20 AMD-2/10 7.00 10.5 64.10 35.90 Non-plastic

21 AMD-2/11 7.30 8.2 59.64 40.36 Non-plastic

22 AMD-2/12 7.60 15.1 56.85 43.15 Non-plastic

23 AMD-2/13 10.00 4.4 86.27 13.73 Non-plastic

24 AMD-2/14 10.30 3.4 87.25 12.75 Non-plastic

25 AMD-2/15 10.60 4.6 81.28 18.72 Non-plastic

26 AMD-2/21 20.60 39.5 22.10 77.90

27 AMD-2/23 25.30 34.5 26.42 73.58

28 AMD-2/27 27.90 31.3 53.16 46.84

Grain Size analysis Atterberg's Limits

Results of Analysis of Quaternary Sediments - Samples from Ahmedabad City During SPT Work

56


(%)Gravel

(%)Sand (%)

Silt+Clay(%)

Gr. LL(%)

PL(%)

PI(%)


29 AMD-9/1 1.30 8.2 0.00 79.64 20.36 Non-plastic

30 AMD-9/2 3.30 6.2 6.36 74.21 19.43 Non-plastic

31 AMD-9/3 7.30 13.0 2.09 78.22 19.69 Non-plastic

32 AMD-9/4 12.30 17.3 1.66 63.46 34.88 Non-plastic

33 AMD-9/5 18.30 19.2 4.08 21.93 73.99 Non-plastic

34 AMD-9/6 24.30 24.0 1.78 41.17 57.04 31.26 19.92 11.35

35 AMD-10/1 1.30 6.2 1.37 68.31 30.32 Non-plastic

36 AMD-10/2 3.30 2.4 2.59 68.56 28.85 Non-plastic

37 AMD-10/3 7.30 11.2 0.47 81.34 18.20 Non-plastic

38 AMD-10/4 12.30 8.1 5.04 40.29 54.67 Non-plastic

39 AMD-10/5 15.30 14.4 6.88 58.90 34.22 Non-plastic

40 AMD-10/6 18.30 16.8 9.33 51.03 39.64 28.75 23.06 5.69

41 AMD-10/7 25.30 16.1 7.23 67.92 24.85 Non-plastic

42 AMD-12/1 1.30 1.14 96.74 2.12 Non-plastic

43 AMD-13/2 5.30 2.71 19.75 60.62 19.63 Non-plastic

44 AMD-13/3 9.30 2.33 25.01 66.15 8.84 Non-plastic

45 AMD-13/4 12.30 7.40 16.65 43.01 40.34 37.30 19.10 18.20

46 AMD-13/5 15.30 16.23 27.15 44.47 28.38 Non-plastic

47 AMD-13/6 24.30 16.42 2.74 74.08 23.18 Non-plastic

48 AKS/AMD/15/1 1.30 1.93 95.21 2.86 2.60

49 AKS/AMD/15/2 5.30 13.21 53.07 33.72 2.59

50 AKS/AMD/15/3 9.30 7.63 40.35 52.02 2.55

51 AKS/AMD/15/4 15.45 11.96 54.41 33.63 2.57

52 AKS/AMD/16/1 1.30 14.58 67.96 17.46 2.56

53 AKS/AMD/16/2 3.30 0.31 91.70 7.99 2.56

54 AKS/AMD/16/3 9.30 14.13 39.71 46.15 2.55

55 AKS/AMD/16/4 18.30 5.71 90.72 3.57 2.54

56 AKS/AMD/17/1 3.30 1.31 20.70 78.00 2.60

57 AKS/AMD/17/2 7.30 8.15 87.03 4.82 2.56

58 AKS/AMD/17/3 15.45 10.14 86.01 3.85 2.55

59 AMD-18/1 1.30 3.37 0.27 77.22 22.50 Non-plastic

60 AMD-18/2 3.30 1.73 0.23 95.83 3.93 Non-plastic

57


(%)Gravel

(%)Sand (%)

Silt+Clay(%)

Gr. LL(%)

PL(%)

PI(%)


61 AMD-18/3 7.30 5.96 10.78 70.36 18.86 Non-plastic

62 AMD-18/4 27.30 11.28 5.09 78.80 16.12 Non-plastic

63 AMD18/5 30.30 7.67 5.04 55.69 39.27 Non-plastic

64 AMD-20/1 1.30 8.10 0.00 71.24 28.76 2.52 23.77 19.79 3.98

65 AMD-20/2 3.30 3.92 2.53 72.98 24.49 2.52 Non-plastic

66 AMD-20/3 5.30 8.90 6.94 32.94 60.12 2.53 16.14

67 AMD-20/4 7.30 4.11 27.15 44.47 28.38 2.54 Non-plastic

68 AMD-20/5 21.30 2.50 11.16 65.09 23.75 2.53 Non-plastic

69 AMD-20/6 24.30 13.70 7.48 56.48 36.04 2.53

70 AMD-20/7 27.30 3.08 16.72 62.79 20.49 2.55 Non-plastic

71 AMD-21/1 5.30 1.18 3.90 72.96 23.14 2.52 Non-plastic

72 AMD-21/2 9.30 1.36 9.65 76.13 14.23 2.52 Non-plastic

73 AMD-21/3 21.30 6.79 1.12 49.59 49.28 2.53 17.14

74 AMD-21/4 24.30 4.96 9.38 56.48 34.13 2.57 Non-plastic

75 AMD-21/5 27.30 9.96 0.76 59.14 40.10 2.54 20.43

76 AMD-22/1 3.30 7.32 2.48 27.21 70.30 2.72 20.18

77 AMD-22/2 5.30 5.98 2.55 49.00 48.46 2.71 Non-plastic

78 AMD-22/3 9.30 14.36 3.50 18.74 77.76 2.41 Non-plastic

79 AMD-22/4 12.30 10.23 6.83 51.78 41.39 2.59 Non-plastic

80 AMD-22/5 18.30 13.70 9.71 69.50 20.79 2.57

81 AMD-22/6 27.30 14.81 5.48 55.51 39.01 2.60 Non-plastic

82 AMD-23/1 1.30 0.97 90.10 8.93 2.63

83 AMD-23/2 5.30 1.81 91.04 7.15 2.65

84 AMD-23/3 7.30 41.02 56.33 2.65 2.65

85 AMD-23/4 18.30 15.30 76.77 7.93 2.43

86 AMD-24/1 1.30 1.04 94.65 4.31 2.59

87 AMD24/2 3.30 0.78 92.42 6.79 2.61

88 AMD-24/3 18.30 10.62 43.29 46.09 2.57

89 AMD-24/4 27.30 16.69 79.86 3.45 2.63

90 AMD-25/1 3.30 0.00 62.10 37.90 41.52 21.69 19.83

91 AMD-25/2 5.30 0.14 44.31 55.55 Non-plastic

92 AMD-25/3 9.30 11.37 83.75 4.88 Non-plastic

58


(%)Gravel

(%)Sand (%)

Silt+Clay(%)

Gr. LL(%)

PL(%)

PI(%)


93 AMD-26/1 9.30 6.01 66.26 27.73 Non-plastic

94 AMD-27/1 7.30 0.43 66.69 32.88 34.43 16.27 18.16

95 AMD-28/1 3.30 0.90 86.30 12.81 Non-plastic

96 AMD-28/2 5.30 5.32 81.56 13.12 Non-plastic

97 AMD-29/1 5.30 4.43 47.24 48.33 31.86 19.50 12.36

98 AMD-29/2 12.30 0.70 71.96 27.34 Non-plastic

99 AMD-30/1 1.30 1.93 39.38 58.70 44.18 24.75 19.43

59

INFORMATION SHEET FOR BIBLIOGRAPHY IN UNPUBLISHED REPORTS

TITLE Seismic hazard / risk microzonation of Ahmedabad city, Gujarat

AUTH Saxena A. K., Prasad, Surendra and Fulzele, D.N.

TDOC Interim Report

CONF Classified

CORP Region : Western

Division : Earthquake Geology

BENE

DCNU Document number : SEI/WR/HQ/2001/007

FSPR 2003-04

DPUP November, 2006

ABST During the course of seismic hazard/ r isk microzonation study of Ahmedabad city, Gujarat, seismotectonic map, ground water level map, soi l map and land use map were compiled. Besides, the Standard Penetration Test ( SPT ) with a truck mounted dri l l machine were carried out in southern part of Ahmedabad city. The area covered during SPT investigation fal ls in toposheet nos 46A/8 & 12 and 46B/5 & 9 and it consists of f luvial and aeolian sediments of Quaternary age.

While carrying out Standard Penetration Test, a total of 30 boreholes each up to 30 meters depth were drilled. The borehole locations were planned at an average interval of 2.5 to 3 Km distance to cover the area inside the Ring Road of AUDA Plan 2011(Ahmedabad Urban Development Agency) of Ahmedabad city within the limit of proposed target of 100 boreholes. Different types of lithological units were noticed during the course of drill ing for the SPT. These units are mainly dark brown coloured silty soil and silt, medium to coarse grained sand and clay in ascending order. These units do not exactly occur in order of their superposition but follow more or less same pattern of occurrence as indicated above. It has been observed that the SPT value (i.e. ‘N’ Value) or number of blows increases with increasing depth. Generally 7 to 30 blows were noticed during the penetration of last 30cm of sampler ( the first 15 cm considered as sitting) up to 12m depth but further below this value increases to more than 50 (a refusal value). The 'N' value are by and large affected by the compaction of sediments, the nature and intensity of kankers occurring in the sediment and the water level occurring in the column. Many kanker beds and alluvial fill deposits (grits, gravels and pebbles) were noticed below 10 m depth which sometimes did not allow the auger drill to penetrate down and the drilling operation had to be suspended. Perched water table zones (0.5 m to 3.00m thick) were also encountered in majority of boreholes between 5 m to 23 m depth. 99 sediment samples were submitted to geotechnical lab for geotechnical analysis. These samples were analysed for grain size analysis, Atterberg’s limits etc.

‘N’ value contour map along with water level contour map were prepared.

The analysis of the SPT data and ground water level map indicate the occurrence of an east -west trending sector which has depth to water level less than 10m and as such is potential ly susceptible to l iquefact ion. The Mani Nagar area is located in the eastern part of this zone which is also characterized by 'N' value less than 10 at SPT conducted at 3.15 to 3.45 m depth. The combination of low N value and shal low ground water explain the greater seismic hazard potential of the Mani Nagar area which suffered a heavy damage during by Bhuj earthquake of 26t h January, 2001.

MPRF Toposheet No. 46 A/8, A/12, 46 B/5, B/9

PROFORMA

Title of the Report : Seismic hazard / risk microzonation of Ahmedabad city, Gujarat

Name of the authors(s) : A. K. Saxena, Surendra Prasad and D. N. Fulzele

1. Background of the investigation at whose instance or with what particular objective in view the investigation was undertaken

: Preparation of Seismic hazard map of Ahmedabad city

2. Whether the item of investigation was included in the approved programme for the year concerned. If so, particulars, such as item No., page reference etc. may be given.

: Yes, Item No. 35 of FSP 2003-04

Page No. 30

3. Date of commencement of the investigation with month and year, and exact number of days spent by the officers(s) in the field in connection with the investigation

: October, 2003, 281 days

4. Brief comments by Director/Supervisory officer on the conclusion and recommendation by the author(s) with suggestion for implementing the same.

: SPT for soils proposed for remaining part of Ahmedabad city in next field season (2004-05) will be useful in the characterization of different seismic microzone

5. Please state specifically how the results of the investigation were achieved compared with the objective for which it was undertaken.

: The objective of the investigation has been achieved

Place : Jaipur Signature :

Date: Name:

Designation. : Director Project/Divn.: Earthquake Geology Division Operation / Region : Western Region

Documents

Seismic Hazard Risk Microzonation of Ahmedabad City