2river

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PROJECT REPORT

ON

RIVER TRAINING WORKS - CASE STUDIES OF

GANGA BRIDGE NO. 52

AND

SHARDA BRIDGE NO. 97

(PROJECT 526 05)

BY

G. Panneerselvam, Dy. C. E. / Br. Line/ S.Rly

Harpal Singh, Sr. D.E.N. / II / Moradabad/ N. Rly.

S.C. Srivastava, Sr. DEN/ Coord./ Lucknow / N.E Rly.

INDIAN RAILWAYS INSTITUTE OF CIVIL ENGINEERING, PUNE

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CONTENTS SL.

No. DESCRIPTION OF ITEMS PAGES

1. INTRODUCTION 1

2. DIFFERENT PURPOSES OF RIVER TRAINING

WORKS

1 2

3. TYPES OF RIVER TRAINING WORKS 2 3

4. DESIGN OF RIVER TRAINING WORKS 3 17

5. CASE STUDY No. 1 OF GANGA BR. No. 52 18 33

6. CASE STUDY No. 2 OF SHARDA BR. No. 97 33 40

7. CONCLUSION 40 41

8. ACKNOWLEDGEMENT 41

9. REFERENCES 41 - 43

10. FIGURES 44 72

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1. INTRODUCTION.

Rivers in alluvial plans are highly variable in their behaviour

and to an average man often unpredictable. A stream, which is

quite trouble free during low flow, may attain a threatening

condition during high stages. It may develop unforeseen

meanders, breakthrough embankment, attack town and important

structures, outflank bridges and in general may create havoc.

Therefore, whenever any hydraulic structure is built across an

alluvial stream, adequate measures in form of river-training works

must be taken to establish the river course along a certain

alignment with a predetermined cross-section. All these works

which are constructed to train the river are known as river-training

works. (Figure1 & 2)

2. PURPOSE OF RIVER TRAINING WORKS:

The objective of the river training works in general includes to

guide and confine the flow of a river channel in a defined course

and to control and regulate the river bed configuration for effective

and safe movement of floods. The basic purpose of river training

works in railways context may be said to be of two folds as under .

(1) To guide the river through the bridges within a constricted

waterway with as little obliquity as possible.,

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(2) To fend the river off the bridge approaches in order to keep in-

tact the line of flow communication.

3. DIFFERENT TYPES OF RIVER TRAINING WORKS

Various types of river training works generally adopted on

Indian Railways are :

(1) Guide Bunds

(2) Spurs

(3) Marginal bunds

(4) Closure bunds

(5) Assisted cut offs

However choice for adaptation of any particular type or a

combination of above river training works depends on various

factors specific to any particular site conditions. In the present

paper, two case studies have been dealt with in detail to

emphasize the above aspects.

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4. DESIGN OF RIVER TRAINING WORKS :

4.1 GUIDE BUNDS :

Aspects of design of guide banks include their shape in plan,

waterway between them; their lengths upstream and downstream

of the bridge axis; curved heads; cross- sections; measures for

their bank and toe protection against scour.

4.1.1 PLAN- FORM:

In plan, the guide banks can either be parallel to each other,

converging upstream or diverging upstream. However, the actual

form of guide banks depends upon the local topography, location

of the bridge with respect to banks, flow conditions in the river and

the alignment of the approach embankments and is best decided

by the model studies.

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4.1.2 Waterway:

The first step in the design of a bridge on an alluvial river is the

estimation of the minimum and also a safe waterway. Laceys

(1929) wetted perimeter P as given by equation no. (1) is used as

a good guide for providing the clear waterway between the

abutments.

Q75.4P = (1)

where,

P is expressed in meters

Q is flood discharge in m3/sec

4.1.3 LENGTH OF GUIDE BUNDS :

Figure 3 shows a typical layout of a straight and parallel

guide bank. According to Springs the straight length of the guide

bank L1 on upstream of the bridge is 1.1 L, and on downstream

side L2 is 0.25L, where L is the length of the bridge between the

abutments.

4.1.4 RADIUS OF CURVED HEAD :

For designing the curved heads both upstream and

downstream (Fig. 3), following recommendations are followed:

For upstream head R1 = 2.2 Q , sweep angle q1 =1200 to 1450

For downstream head R2 = 1.1 Q , sweep angle q2 =450 to 600

Here R1 and R2 are expressed in metres and Q in m3/sec

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4.1.5 TOP WIDTH AND FREEBOARD :

The top width of the guide banks should not be less than 3.0

m and is generally kept between 6.0m to 9.0m to allow for the

movement of vehicles carrying construction material. Side slopes

are generally 2H: 1V. Freeboard 1.5m to 2.5m above the

anticipated maximum flood level of 100-year flood. Alternatively, a

freeboard of 1.0m is added to the high flood level of a 500-year

flood for getting the top level of the guide bank.

FIGURE 3 LAYOUT OF A GUIDE BUND

Deepest Scour Hole

1:2 (V:H)

Launching Apron

H.F.L.

Section A-A

Section B-B

H.F.L. H.F.L.

Launching Apron

Deepest Scour Hole

2 2R = 1.1 Q2

R2

R = 2.2 Q1

1

R1

1

A A

B

B

1

2

Flow

L = 1.1L

L = 0.25L

1

Top Width

Rear Apron

Side Slope

Front Apron

Axis of the Bridge

L

L

q = 120 to 145

q = 45 to 60

1:2 (V:H)

q

q

o

2

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4.1.6 Stone Pitching On Sloping Sides And Launching Apron:

The sloping face of the guide bank as well as its nose are

susceptible to severe erosion by the river flow, therefore, they are

protected by large size stones . Normally the thickness of such

stone pitching on the slope is estimated by the following empirical

equation given by Inglis (Garde and Ranga Raju, 2000)

T = 0.04 to 0.06 Q1/3 (2)

where,

T = Thickness of the pitching in metres and Q is in m3/sec

This pitching should extend upto 1.0m higher than the

expected maximum flood level. Further, it should be ensured that

the minimum size of the boulder used in this pitching is such that it

is not washed away during flood. This minimum size of stones of

relative density 2.65 may be calculated by the following empirical

equation as given by Garde and Ranga Raju (2000).

dmin = 0.023 to 0.046U2max

(3)

in which

dmin is expressed in m, and U max is the maximum velocity of

flow (in m/s) in the vicinity of guide bank.

A geosynthetic filter or a conventional sand gravel filter

0.30m thick is generally placed on the sloping bank of the

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guide bank facing river flow to prevent washing out of fine

material from the subgrade or backfill and the pitching is

provided over this filter. The pitching is placed in a closely

packed formation inside a grid formed by masonry walls of

0.30m width provided along the bank slope at a spacing of

6.0m measured in the direction of flow.

4.1.7 LAUNCHING APRON :

Figure 4 shows the general arrangement of the launching

apron that is generally provided at the head and the shank of

the guide bank to prevent undermining of the bank pitching

and consequent failure of the guide bank. The design of the

launching apron involves the estimation of the maximum

scour that is likely to occur at different portions of the guide

bank and the provision of the adequate quantity of stone to

cover the face of the scour hole at that location.

Inglis (Garde and Ranga Raju, 2000) has related this

maximum scour depth D1 to Laceys depth R as per the

following relation:

D1 = XR (4)

where,

R = 0.473/1

fQ (5)

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Here D1 and R are both measured from the high flood level

and are expressed in metres; Q is in m3/sec and f is Laceys

silt factor given as

f = 1.75 50d (6)

in which d50 is the median size of the bed material in mm and

the coefficient X is taken from Table1.

Table1 Values of X in Equation (4)

Location Value of X

Scour at straight spurs facing upstream 3.8

Scour at straight spurs facing downstream 2.25

Scour at nose of large radius guide banks 2.75

Transition from nose to straight portion of

guide bank 2.25

Straight portion of the guide bank 2.0

It is assumed that the launching apron placed on the river

bed would launch into the scour hole to take a slope of IV: 2H with

an average of 1.25T. To ensure this volume of boulder material,

the average thickness of the launching apron on the riverbed

comes to 1.86T.The apron is originally laid on the riverbed in a

width of 1.5Ds where Ds is the scoured depth measured below the

bed at that location.

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To account for the non-uniformity in launching, the thickness

of the apron calculated above is provided in the form of a

wedge as shown in Fig.4.

FIGURE 4 DETAILS OF A LAUNCHING APRON

Thus, making use of Table 1 and Fig.4, the widths of the

launching apron at various locations of the guide bank can be

estimated. Smooth transitions need to be provided to

accommodate the varying widths of the apron.

4.2 PERMEABLE SPURS

Permeable spurs have been used more often for bank protection

than for diverting the flow. These spurs stabilise a reach of the

river by inducing siltation along the bank from which they are

H.F.L.

Average Thickness 1.25T after Launching

River Bed

Deepest Scour

1.5 T

20 cm Soling of Ballast

1:2 (V:H)

Boulder Pitching

Total thickness including Soling (T)

2.25Ds

1:2 (V:H)

sD

1D = xR

Launching Aprons

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projected. They are generally provided as a series of spurs

projecting from the bank, which requires protection against

erosion. Design considerations include their cross-section, length

and spacing, stability and protection against scour.

4.2.1 CROSS- SECTION :

Spurs are built of rectangular section with a top width of about 1.50

m. Vertical ballies' (wooden piles made of bamboos) are driven in

two rows at the spacing equal to top width of the spur. They are

tied longitudinally, laterally and diagonally for achieving greater

rigidity and strength. The space between the two rows of ballies'

is filled with brushwood and stones. The recommended

thicknesses of brushwood and stones to be placed in alternate

layers are 0.90 m and 0.30 m respectively. It is also suggested that

the spur should have a permeability of about 40%.

4.2.2 LENGTH AND SPACING :

There is no specific information available regarding length of these

spurs. The length is however decided mainly from the

consideration that these spurs are required to promote silting and

not to deflect the current away from the bank. Further, short spurs

would have comparatively less hydrodynamic force on them

thereby reducing the chances of their failure. The width of the river

is also considered in fixing the length of the spur. For the railway

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bridge at Garhmukteshwar the width of the river during high flood

in the reach affected by bank erosion was 300.0 m and permeable

spurs of 10.0 m long were proposed.

4.2.3 STABILITY OF PERMIABLE SPUR :

The main criterion for the stability of the spur is that it should

not overturn under the various forces that act on it. The stability on

the basis of this criterion should be examined both in the

unscoured and scoured conditions. Therefore, the length of the

ballies below the riverbed should be adequate to ensure their

stability.

For the stability analysis, the spur is considered as a

permeable, two-dimensional anchored pile. The various forces to

be considered per unit length of the spur are as below and are

shown in Fig.5

(i) Drag force , FD

(ii) Soil resistance, Fs

(iii) Self weight of the spur, W

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The method of estimating these forces is given below:

FIGURE 5 FORCES ON THE SPUR

Drag force, FD :

The drag force per unit length is conventionally expressed as

FD = C D 21 f U

2 Hs (7)

in which CD is the drag coefficient of the spur, r f is the density

of water, Hs is the height of the spur above the river bed. Here

the value of CD can be estimated using the results of Ranga Raju

et al.(1988) for the flow past porous fences as shown in Fig.6.

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FIGURE 6 RELATIONSHIP FOR CD

In this figure d is the thickness of the boundary layer, Hf is

the height of the fence and h is its porosity. The relationship shown

in Fig. 6 does not consider the effect of blockage on CD. As the

length of the spur is generally quite small in comparison to river

width, the effect of blockage on CD could be ignored. For the spur

projecting from the river bank, Hf is taken as the length of the spur

and d as equal to half the width of the river

The value of CD also depends on the angle of inclination of

the spur. However, the results of Ranga Raju and Garde (1969)

show that for the angle of inclination between 600 and 900, the

value of CD remains practically constant.The drag force FD may

be taken to act at Hs/2 above the river bed level.

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Soil resistance, Fs :

For considering the overturning of the spur about its base, the soil

resistance Fs per unit length of the spur is computed using the

following equations (Ranjan and Rao, 1991)

Fs=21 g, (kp - ka ) D

2 (8a)

kp = tan2 (45 + j /2 ) (8b)

ka= tan2 (45 - f /2 ) (8c)

Here g, is the submerged weight of the soil, f is the angle of

internal friction and D is the depth of ballies below the river bed. In

calculating the value of Fs from Eq.(8), the extra resistance

offered by the launching apron has not been considered. This

assumption would give the value of Fs on the conservative side.

The line of action of the force Fs is at 2D/3 below the river bed

level.

Self weight of the spur, W:

The self weight of the spur, W, per unit length may be computed

as

W = s b (Hs + D) (9)

in which s is the submerged unit weight of the spur material

and b is the width of the spur. This weight acts vertically down

at b/2 through the centre of gravity of the spur.

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4.2.4 STABILITY ANALYSIS IN UNSCOURED CONDITION :

Figure 7 shows the forces on the spur in the unscoured

condition. The unknown grip length D of the spur below riverbed

could be calculated with these forces and adopting no tension

criterion in which resultant of all the forces passes through a point

within the middle third of the base.

FIGURE 7 FORCES ON THE SPUR IN UNSCOURED CONDITION

Stability analysis for the required grip length with scour

Figure 8 shows the spur, with deepest scour at its nose and the

resulting launched position of the apron.

As can be seen from this figure, the soil has a sloping profile of

IV:2H below the bed level. For the computation of soil resistance in

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this case, the effective depth of soil has been assumed as 2/3D

instead of the full depth D. This is shown as equivalent horizontal

soil level in Fig.8. Here D is the required grip length below riverbed

level. Following the criterion of no tension at the toe, the required

grip length D can be worked out. The resistance offered by the

launched apron will provide additional margin of safety.

FIGURE 8 FORCES ON THE SPUR IN SCOURED CONDITION

4.2.5 Stabi lity of spur at the riverbed level

In analyzing the stability of the spur at the riverbed level, it is

assumed that the grip length as estimated on the basis of scour

condition will provide enough rigidity at the riverbed level for

considering the bending of the spur. This bending needs to be

considered under the action of various forces acting on it above

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the riverbed level. Schematic diagram showing forces on the spur

above the riverbed level is shown in Fig.9.

FIGURE 9 FORCES ON THE SPUR ABOVE THE RIVERBED LEVEL

Also, the spur above the riverbed may be assumed as a solid

structure though it will function as a permeable spur to start with.

The assumption is on the conservative side. The analysis requires

permissible stresses on the ballies used for the spur. These

stresses depend on the grade of the timber used for ballies and

are given in National Building Code of India (1970). Knowing

forces shown in Fig.7, the analysis can be carried out to determine

the factor of safety against overturning and stresses at the toe and

heel of the spur. The width of the spur could be modified if required

on the basis of such an analysis. Protection against scour at the

nose of these spurs is provided in the form of the usual launching

apron.

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5. CASE STUDY NO. 1: RIVER TRAINING AND PROTECTION

WORKS AT BRIDGE NO. 52 ON RIVER

GANGA AT GARHMUKTESHWAR ON

MORADABAD-GHAZIABAD-DELHI (BG)

RAILWAY LINE ON NORTHERN RAILWAY.

5.1 BRIDGE DETAILS(Existing) :

Span - 11 x 61 m.

Design Discharges - 7600 cumecs

Foundation - Well foundation in brick masonry

(5.00 x 10.00 m round nose & 25 m

Depth, stein. 1.20 m)

Rail Level - 204.9 m.

Bottom of girder - 202.44 m.

H F L (1924) - 200.25 m

Danger level - 199.35 m.

L W L - 195.4 m.

Permissible scour level - 183.0 m

Bottom of foundation - 169.7 m

A Road bridge of span 2 x 53.30m + 11x 54.21 m also exist

at 180 m on down stream side of this bridge .

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5.2 BRIDGE DETAILS(In Progress 30 m D/S of existing) :

Span - 11 x 61 m.(UP/DN)

Design Discharges - 8300 cumecs (Return period 50

year)/12748 cumecs(Return period 2000 years corresponding

to H.F.L of 1924)

Foundation -Well foundation in R.C.C 2.5 m Stein.

- Pier 12 m circular & 48 m Depth with

- Abut. 12m circular & 46.6 m Depth

Rail Level - 204.9 m.

Bottom of girder - 202.44 m.

H F L (1924) - 200.25 m

Danger level - 199.35 m.

L W L - 195.4 m.

Permissible scour level - 170.25 m

Bottom of foundation - 147.93 m

A Road bridge of span 2 x 53.30m + 11x 54.21 m also exist

at 150 m on down stream side of this bridge and another is in

progress 14.80m up stream of existing road bridge.

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5.3 STATEMENT OF PROBLEM :

Moradabad-Ghaziabad line of Northern Railway,crosses river

Ganga near Garhmukteshwar at km 66/8 to 67/4.The Ganga at the

bridge site ,in alluvium stage with sand (Silt factor 0.9) in its bed, is

nearly 500 km down stream of its source of origin and catchment

area is approx. 29709.0 sqkm. At the time of construction, river

with Khadir width of 7-8 km was flowing hugging its extreme edge

of khadir on Ghaziabad side.The bridge was constructed in 1900

with guide bunds 670 m long on u/s side and 150 m long on

downstreamside for right guide bund.Similarly 460 m long on u/s

side and 150 m on d/s side for left guide bund were constructed.

Left guide bund was kept shorter than the right guide bund,

keeping in view the proximity of the edge of the island. Mr. W.A

John, who constructed the bridge,clearly recorded that length of

left guide bund has been purposely kept shorter to allow more

passage of water in between the guide bund and island.He further

recorded that if required,its length can be increased.Since

constrction of this bridge the river has been changing its course

intermittently causing serious threat to left approach

embankment,guide bund and also to right guide bund .Till date

various studies and protective measures have been/are being

taken.After construction of one spur of 600 feet long during 1903

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,1500 feet away from left, the river straightened itself and caused

no serious problem till 1947except in 1924 when flow of river was

only 200 m away from the Matwali bridge and some portion of the

Ganga flood water was diverted towards Matwali bridge.As such

breach took place in the approaches of Matwali Bridge.After the

breach,span was increased from 3x12.2 to 6x12.2m.Depth of well

foundation was increased from 12.5 m to 21.3 m (for newly

constructed wells). Two bridges,one each at Chhoiah Nallah

(Bridge no 50) and Matwali Nallah(Bridge no 51)were provided to

avoid flooding of water in nearby area for longer duration

considering that these bridges will pass on the discharge to the

down stream side.(However it is suspected that during the heavy

flood, river Ganga also somewhat attracted towards the bank due

to bridge constructed over Matwali Nallah.Sometime it was feared

that river may outflank through Matwali bridge.Later on,Railway

administration corresponded with the State Govt. regarding closure

but the same could not be materialized on account of resistance of

the villagers on the plea that they will be mostly submerged in

water). During the flood of 1948, the river attacked railway bank at

km 63-64. Member engineering flew over the site and in

consultation with C.W.P.R.S/Pune the left guide bund was

extended by 1200 feet with additional curved head of 600 feet

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radius. A 4.5 km long diversion was constructed from km 66/11 to

65/12 .The river immediately after execution of these works

retreated back. Again in floods of 1950,1954,1956,1977,1996,1998

some flood repair works were carried out on the left approach bunk

and the guide bunds by dumping boulders and

constructing/extendig solid and permeable spurs.During

1955,nearby Tigree & Lathira villages were endangered and

Lathira village partly washed away.To protect the villages , one

spur was constructed thereby tying the river between to obligatory

points i.e Tigree spur and guide bund of Garhmukteshwar bridge,

meandering and coming close to embankment .

For protection measures various further studies were got done by

Railway from IRI /Roorkee in 1978,1980 ,from IIT/Roorkee in

1997,1999. Based on them a large number of solid and permeable

spurs have been provided on the left bank of the river for

controlling the flow so that the railway embankment is not subject

to bank erosion.(In 1996 & 1998 in a reach X1X2 (a distance of

about 825m) as shown in Fig.l,in fact at location 64/7 km on this

reach, the river is only 70. m away from the centre line of the track

and is subject to serious bank erosion. Therefore protective

measures were to be taken immediately).A barrage 70 km

upstream has also been commissioned in 1988 from which canal

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takes off from right bank.

However, before a further detailed physical model study

could be conducted, a new Railway Bridge as well as a new

roadways were also sanctioned for construction within 180 m in

down stream side of existing Railway Bridge and in up stream side

of existing road bridge. Keeping in view the fact that the

construction of these two new bridges in close vicinity of existing

bridges may further affect the river behaviour, it was thought

prudent to have a fresh detailed study including physical model

study taking holistic consideration of all aspects including effect of

existing and proposed ghats. Accordingly department of civil

engineering of IIT Roorkee along with Irrigation Research Institute,

Roorkee were asked for a detail study and interactive design.

Based on their recommendations submitted in year 2004 various

further measures as detailed below are being adopted at site.

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5.4 RECOMMENDED REMEDIAL ACTIONS TAKEN IN

VARIOUS STAGES :

(I) Year 1903:

600 feet left embankment spur at 1500 feet from abutment

constructed.

(II) Year 1948: River main channel was only 480 feet away from

track. . On Member engineering visit to site and in

consultation with C.W.P.R.S/Pune the left guide bund was

extended by 1200 feet with additional curved head of 600

feet radius. A 4.5 km long diversion was also constructed

from km 66/11 to 65/12 .

(III) Year 1950: UP Govt. constructed a spur to save village tigri

situated 8 km u/s of bridge.However since then the river has

been flowing hugging this spur and passing through railway

bridge.

(IV) Year 1954: Repairs by dumping boulders along railway

embankment & linking track on diversion.

(V) Year 1956-58: IRI/oorkee recommended curved mole head

for right guide bund and 3500 feet long spur at km 63-

64.Somehow none of these proposal materialized.

(VI) Year1977: Diversion repaired with 16 feet bank width and

1.5 : 1 side slope.A reseve stock of 1lakh cft of boulders at

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km 63-64 was also collected and kept.With the

commissioning of earthen dam over river Ramganga at

Kalagarh the dry weather flow of river ramganga is

discharged in River Ganga 4 km u/s of village Tigri to

augment discharge of lower ganges canal taking off from

Narora Since the current at km 63/7-8 was 10-12 feet deep

the const. Of even small spures to arrest the local erosion

could not be taken up as time leftover was very little.

(VII) Year 1978: IRI/ROORKEE in1978( report no50) suggested

two spurs one 250 m long at km 64.06 and another 400 m

long at km 65.50 normal to the track based on model study.

(VIII) Year 1980: IRI/Roorkee in1980( report no51) suggested (i) A

kinked spur having 60 m shank length and 90 m nose at 165

degree included angle at km 63.75(ii) Existing 50 m long

inclined spur at km 65 may be extended straight normal to

track beyond its nose making total length 100m.(iii) A mole

head of radius 200m at 120 degree sweep angle may be

provided to the nose of right guide bund.

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(IX) Year 1981 :

(i) 305 Nos. large size trungers dropped around the nose of

spur at KM: 63 /12.

(ii) 3000 trees planted on the RGB, LGB and along the bank of

Ganga.

(iii) Turfing of the slops of retarded alignment was done.

(X) Year 1997 :

Department of civil engineering of the then University of

Roorkee had suggested in its 1st report that following action should

be taken as short term measures to safeguard the bridge guide

bunds an its approach embankments from any threat in oncoming

monsoon.

1. Twenty five permeable dikes 5. 0m long at a spacing

of 30 m and at locations shown in Fig.15 be

constructed on the left bank of the river. The construction

details of the dikes and the launching apron are given

in Fig.16.

2. A pilot channel 10.0m wide, 1.0m deep and 225.0 m

long be excavated on the existing bed opposite the

proposed location of the dikes to reduce the discharge

intensity in the main channel in the vicinity of the dikes.

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3. Sandbag revetment be provided on the left bank

both upstream and downstream of the proposed

dikes. The length of revetment may be 100.0m on

the upstream side and 50.0m on the downstream side.

While follow up action on item No. 1 and 3 were taken at site,

action on item No. 2 was deferred till detailed model study as its

efficacy was considered doubtful.

(XI) Year 1999:

However, before a detailed physical model study as earlier

recommended by IIT, Roorkee, could be got conducted, serious

problems were felt in flood of 1998 and 1999. The river came very

close to the railway embankment over a distance of 825 m posing

a serious threat to its safety. Nose of exisiting spurs along with

molehead of the existing left guidebund were seriously damaged.

Department of a Civil Engineering of IIT, Roorkee were again

requested to study the following aspects :

To examine the need of extending the newly built solid spurs.

Identification of the number and the location of additional solid

permeable spurs on the left bank of the river

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To suggest safety measures for the protection of the molehead of

the left guidebund of the bridge and the existing solid spurs.

IIT Roorkee, based on a detailed theoretical analysis

recommended that

(a)To extend all the three solid spurs that were built during

1998(shown in fig.20).

(b)To build two new solid spurs at locations Km 64/8-9 and 65/4-

5(Shown in fig. 20)

(c)To build a series of permeable spurs 5 m long at 30 m center to

center spacing in the entire affected reach (Shown in fig.20 ).

(d)To strengthen the molehead of the existing left guide bund and

the three solid spurs built in 1998.

(e)To provide stone pitching along the left bankline over a distance

of 100 m u/s of the existing solid spur at km 64/3-4and over a

distance of 100 m d/s of the last permeable spur (Shown in fig. 20)

(XII) Year 2004 :

As the basic purpose of study conducted in 2004 was to study the

behavior of river based on holistic approach the scope of the study

to be conducted by Irrigation Research Institute Roorkee included:

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(a) To study the effect of river stream on left and right guide bunds

and other river training works required to protect railway

embankment as well as bridge.

(b) To study for making uniform distribution flow of water from all

spans of bridges during monsoon.

(c) Scour depth in the vicinity of bridge piers.

(d) Shape and section of piers.

(e) Merging of Nala into right guide bund.

(f) Any other suitable suggestions.

A model study based on distorted model of River Ganga from

about five km up stream to 4 km down stream of existing Railway

Bridge Built on scales 1 in 250 (horizontal ) and 1 in 40 (Vertical)

was conducted by Irrigation Research Institute Roorkee to

examine the efficacy of various measures suggested by

department of Civil Engineering, IIT Roorkee based on theoretical

considerations. Various measures suggested by department of

Civil Engineering, IIT Roorkee based on theoretical considerations

were as under :

1. Afflux at the existing railway bridge is expected to be less than

10.0 cm and the freeboard provided at the guide bunds is

adequate.

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2. The right guide bund is required to be extended on the

upstream side along its straight length by 107.0 m keeping the top

width the same as in the existing guide bund, viz. 13.0 m and by

providing side slopes of IV: 2.0 H. berms on both sides of the

sloping banks of the extended straight length of the right guide

bund be provided at the same level as in the existing right guide

bund viz. 198.058 m. The width of these berms may also be kept

the same as in the straight portion of the existing right guide bund.

3. The curved head at the end of the extended portion of the right

guide bund be provided as per the details shown in Fig. 23.

4. The bank revetment and the launching apron in the modified

portion of the right guide bund i.e. straight extended length and the

curved head be provided as per the details shown in Figs. 23,24

Geosynthetic filter is recommended instead of sand-gravel filter in

view of quality control and convenience in its laying.

5. The mole head of the existing left guide bund be modified as per

the design proposed for the curved head of the right guide bund.

The details of the proposed modifications are shown in Fig. 26.

6. A 850.0 m long pilot channel 10.0 m wide, 1.0 m deep with

1V:2.0 H side slopes as shown in Fig. 18 be excavated on the

existing' island along the left guide bund to reduce the

concentration of main flow on the right bank of the river. The

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channel is to be excavated below the existing surface level of the

island.

7. Provision of Ghats on the upstream side on the right guide bund

is recommended as such a provision is not expected to alter the

flow characteristics from what have already been considered in the

present design. The rise and the tread of the steps in these Ghats

would however, need adjustments as per the existing and the

proposed side slopes of the right guide bund.

However during the detailed model study by Irrigation Research

Institute Roorkee, it was found that extension of right guide bund

by 107 m in upstream and construction of a pilot channel as

suggested by IIT Roorkee have no effect on activating the left side

spans and channel was found to get silted during the recession of

flood as such these two items were dropped and various other

measures as suggested by IIT Roorkee and found to be

satisfactory in Irrigation Research Institute Roorkee Report are

being implemented at site as detailed (fig. 22)

6. Case study II :

River training and flood protection works between Br. No. 97

and Br. No. 98 between Palian Kalan Bhirakheri Station on

Mailani Gonda (MG) Section of N.E. Railway.

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6.2 Details of Br idge No. 97

Rail cum Road Bridge 19 x 24.38 m

Location 241/ 1-5

Rail Level 158.95 m

Maximum scour Level 14.85 m below Rail Level

Bottom of Girder 156.80 m

Danger Level 155.00 m

Top of Foundation 7.68 m below Rail Level

Bottom of Foundation 25.98 m below Rail Level

Highest Flood Level 155.32 m (1934)

Length of Guide Bund (Plain end) 472 m

Length of Guide Bund (Bhira end) 500 m

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6.2 Details of Bridge No. 98

Rail Bridge Span 9 x 6.1 m + 1 x 12.2 m

Location 247/ 7-8

Rail Level 157.38 m

Top of Girder 157. 16 m

Bottom of Girder 155.80 m

Danger Level 155.20 m

Floor Level 153.375 m

Highest Flood Level 156.32 m (1987)

Length of Guide Bund (Plain end) 77 m

Length of Guide Bund (Bhira end) 73 m

Statement of Problem

River Sharda crossed the Mailani Gonda (MG) Railway

Line through a 501.92 m long rail-cum road bridge no 97 in district

Lakhimpur Kheri. Earlier the river course was almost straight and

perpendicular to the bridge. However during last 10 years the river

Sharda, due to meandering towards right has taken a sharp curve

in which flow is taking about 180 degree turn and river has come to

very close (even up to 15 m) to the railway embankment posing

serious threats to its safety (Fig. 27). Furthermore due to its

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meandering and coming very close to the Railway track, a

significant part of River flow has started passing through a smaller

bridge No.98 (9x 6.1 +1 x 12.2. m) situated in u/s side of bridge

No. 97. It is apprehended that flow of exceptionally high discharge

through bridge No. 98 and parallel to Railway embankment in

close proximity of 15-30 m may cause serious damage to the

bridge No. 98 and Railway embankment in this stretch. Discharge

in the river Sharda is controlled by a barrage of UP Iriigation Dept

at Banbasa which is approximately 100 km of u/s of bridge No. 97.

6.3. RECOMMENDED REMEDIAL ACTIONS.

Originally the river Sharda was flowing quite away from the

Railway embankment between bridge No. 97 and 98 and was

crossing bridge No. 97 almost perpendicular to the track. However

it started meandering towards Railway embankment around 1990.

There upon UP Irrigation Department was requested to under take

necessary river training works. Accordingly UP Irrigation

department planned a scheme of Rs. 1.36 Cr. in the year 1990.

But no work was actually done by them.

Thereafter UP state Irrigation department again finalized a

scheme of provision of 40 No. spurs (16 m long @ 60 m c/c at a

cost of Rs 1.84 cr.) to control its meandering. However only 3

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spurs out of 40 could be constructed which were also seriously

damaged in monsoon.

In the mean time, U.P govt. appointed a committee of three

chief engineers to study the problem and suggest remedial

measures .The committee has recommended provison of sufficient

no of spurs along with a cunnette/marginal bund. Based on above

a detailed model study was conducted by irrigation research

institute Roorkee ,which recommended construction of 10 km long

cunnette along with a 12 km long bund with boulder pitching, which

was estimated to cost rs 164.64 cr.

Since then Railway has been consistently requesting the UP

Irrigation Department to undertake necessary river training works

but no work was actually done by them. In the mean time the river

came very close to the Railway embankment and Br No. 98,

posing serious threat to its safety itself. To ensure the safety of

Railway embankment & Br. NO. 98, following works were executed

by Railway in different stages:

(i) Construction of 35 no spurs in different stages(Fig. 28 & 35).

(ii) Strengthening and extension of the guide bund of Br. No. 98.

(iii) Strengthening of the flooring system of Br. No. 98 (Fig. 34).

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However as the cost of the river training works as suggested

by IRI Roorkee was exorbitantly high , UP Irrigation department

again referred this problem to Irrigation Research Institute

Roorkee to suggest alternative cost-effective river training works

taking into account various flood protection works already

executed at site by Railway dept. After a detailed physical model

study in Jan 2004 considering following alternative

(a) Provision of 8.65 km long marginal bund with 100 m

wide cunnette at 350 m from bund (Fig. 36).

(b) Provision of 11 km long marginal bund with 200 m wide

cunnette at 275 m from bund (Fig. 37).

(c) Provision of 11.10 km long marginal bund with 200 m wide

cunnette at 685 m from bund (Fig. 38).

(d) Provision of 4.10 km long marginal bund from Railways existing

spurs (Fig. 39).

(e) Provision of 4.10 km long marginal bund with spur and

extention of 8 nos Railways existing spurs (Fig. 40).

IRI Roorkee in its report of march 05 has recommended for

Construction of 4.00 km long marginal bunds along with spurs /

studs along the right bank of river Sharda in up stream of the

Railways flood protection work (and Bridge No. 98) and extension

of existing 8 no. spurs constructed by the Railway. It also

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recommended that extension of existing spurs along Railway

embankment and construction of new spurs along proposed

marginal bunds should be constructed in 1 working season. It is

estimated to cost approximately Rs. 25 Cr.

However there is now a dead lock about financing of the

above scheme. State Government is demanding the full fund from

the Railway on the pretext that this work is to be executed by

them for protection of Railway bridge and track , and therefore

full cost is to be given by the Railway. However Railway is

opposing the above on the ground that this work is not for safety of

Railway bridge and track only but also for the safety of Civil area.

Further more the Railways also say that scope and cost of work

has increased so much only because of timely action not taken by

state govt. and therefore Railway is not liable to pay. This issue

needs to be resolved still.

Br. No. 98 has got 9 girders of span 6.1 m each and 1 girder

of span 12.2 m. The bottom of girder of 12.2 m span is 590 mm

below the bottom of the girder of 6.1 m span due to which many

times water level in 12.2 m span comes above bottom of its girder

whereas water level in other spans of 6.1 m length still below

bottom of girders necessitating suspension of traffic. As such

changing of girder of 12.2 m span with the restricted height has

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been got sanctioned and is to be executed during current year so

that suspension of traffic on this account may be eliminated.

7. CONCLUSION :

7.1 It is seen from the above case studies that timely action in

provision of various river training works not only mitigates

serious threat to the safety of Railway bridges and

embankment at later stages but also prevents many fold

escalation of cost.

7.2 It is also noted that many times obvious theoretical measures

contemplated for river training works may not be required at

all or may even be counter productive. Therefore it is

desirable to go for detailed physical model studies before

undertaking any major river training works.

7.3 The River Training works after model study should be

implemented expeditiously i.e. without delay.

7.4 Trees planted on and along guide bunds/ spurs serve as

natural protection measures.

7.5 For more effective results spacing of solid spurs should be

kept between 2 to 3 times of their lengths & permeable spurs

used for bank protection be spaced at 5 to 6 times their

length.

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7.6 Distribution of discharge through all bays useful for safety

and economy of bridge can be achieved through suitable

river training works like bed bars etc.

7.7 Execution of river training works require special attention.

The mole head of the left bank of Ganga Bridge need

Geometric correction and left bank spurs need further

strengthening keeping in view HFL of 1924.

8. ACNOWLEDGEMENT :

Authors gratefully acknowledge the assistance and guidance given

by Shri N.C. Sharda, Sr. Professor Works, Indian Railways

Institute of Civil Engineering, Pune for the Project Report.

9. REFERENCES :

i. Indian Railways Bridge Manual 1998

ii. River Behaviour management and Training, Publication No.

204, Volume 1 1989 by Central Board of Irrigation and power

N. Delhi

iii. Indian Railways Standard Code of Practice for the Design of

Substructure and foundations of Bridges.

iv. Member Engineering, Railway Board New Delhi, Technical

Paper No. 6.

v. Irrigation Research Institute Roorkee Report No. 50 of 1978.

vi. Irrigation Research Institute Roorkee Report No. 51 of 1980.

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vii. Irrigation Research Institute Roorkee Report No. 75 RR

(H105 ) of 2004.

viii. Irrigation Research Institute Roorkee Report No. 75 RR (H1

07 ) of 2005.

ix. Report on Protection of Left Bank of the River Ganga

Near Garhmukteshwar Railway Bridge of Department of

Civil Engineering of IIT Roorkee dated Jun1997.

x. Report on Measures for Control of Erosion of Left Bank

of the River Ganga Near Garhmukteshwar Railway

Bridge of Department of Civil Engineering of IIT Roorkee

dated Mar 1999.

xi. Proceedings of Workshop on Bridge scour, River Training

and Protection works by Department of Civil Engineering and

Bridge Engineering Group of IIT Roorkee dated Oct 2003.

xii. Final Report on Hydraulics Design of Proposed Railway

Bridge on the River Ganga at Garhmukteshwar of

Department of Civil Engineering of IIT Roorkee dated July

2004.

xiii. IS:10751 (1994), Planning and design of guide bunds for

alluvial rivers, Guidelines, BIS, New Delhi.

xiv. Lacey G. and Inglis, C.C. (1944), Maximum depth of scour

at heads of guide banks, groynes, pier noses and

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downstream of bridges, Annual Report (Technical),

CWPRS, Pune.

xv. Ranga Raju, K.G.(1993), Flow through open channels , Tata

McGraw Hill Publishing Company Limited, New Delhi.

xvi. Ranga Raju, K.G., Mittal, M.K., Verma, M.S. and Ganeshan,

V. (1980), Analysis of flow over baffle blocks and end sills ,

Jour. of Hyd. Research, Vol. 18, No. 2, pp. 227-241.

xvii. River Training and Protection Works for Railway Bridges.

Published by IRICEN, Pune.

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FIG 1: TYPICAL LAYOUT OF GUIDE BUND

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FIG.2

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FIGURE 10 : COURSE OF RIVER GANGA IN 1900 AND 1978 AT

GARHMUKTESHWAR RAILWAY BRIDGE

U.P. I R I ROORKEE TRAINING OF RIVER GANGA AT GARHMUKTESHWAR BR. NO. 52

INDEX PLAN

1978

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FIGURE 11: TOPOGRAPHICAL AND HYDROLOGICAL MAP OF GANGA BRIDGE NO. 52

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FIG

.12

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FIG

.13

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FIG

. 14

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FIG

. 15

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FIGURE 15a :

COURSE OF RIVER GANGA IN 1996 AT GARHMUKTESHWAR

RAILWAY BRIDGE

Dry Channel (B)

Railway Crossing No. 49

km 64/7X2

X1

km 65/0

BarLeft Guide Bank

km 66/0

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FIGURE 16: PLAN VIEW OF PROTECTION WORKS USING PERMEABLE SPURS

30m

A

GHAZIABADMORADABA

DRAILWAY TRACK

km 64/7

EXISTING SPUR

EXISTING BANK LINE PROPOSED DIKES

PERPENDICULAR TO THE EXISTING BANK

EXPECTED BANK LINE

REVETMENT(ABOUT 100m LONG)

BARPROPOSEDPILOT CHANNEL

RIVETMENT(ABOUT 50m LONG)

B

4

1

101520

25

5

X

X2X

1

825m

RAILWAY CROSSING No. 49

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FIGURE 17: DETAILS OF THE PROTECTION WORKS FOR THE SPUR

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FIG.18 (a)

FIG.18 (b)

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FIG. 19 : COURSE OF THE RIVER GANGA IN 1997 AND 1998 AT

GARHMUKTESHWAR RAILWAY BRIDGE NO. 52

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FIG. 20 : PLAN VIW OF PROPOSED PROTECTION WORKS FOR LEFT BANK OF GANGA BRIDGE NO. 52 (IITR 1999 REPORT)

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FIGURE 21 : PROPOSED SOLID SPUR AT LOCATION 65 / 4 - 3

H.F

.L 2

00.2

5 H

.F.L

200

.25

195.

54 m

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FIGURE 22 : FINAL PROPOSAL FOR PROTECTION WORKS

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TA

BL

E 2

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FIG. 23

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FIG. 24

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FIG. 25

26

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FIGURE 26 : PLAN AND SECTIONS SHOWING DETAILS OF THE MODIFICATIONS FOR THE MOLE HEAD OF THE LEFT

GUIDE BUND

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FIGURE 27 : COURSE OF THE RIVER SHARDA BETWEEN

1991 TO 2004 BRIDGE NO. 97 & 98

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FIGURE 28 : PLAN SHOWING RIVER SHARDA EDGE

BETWEEN BRIDGE NO. 97-98 AS ON 12-08-2004

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FIGURE 29 : VIEW OF RIVER SHARDA DURING FLOOD (TREE PLANTATIO ACTING AS NATURAL PROTECTION MEASURE / SPURS)

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FIGURE 30 : VIEW OF RIVER SHARDA DURING FLOOD

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FIGURE 31: VIEW OF RIVER SHARDA DURING FLOOD AT BRIDGE NO. 98

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FIGURE 34 : DETAILS OF PROTECTION WORKS OF FLOOR AND EMBANKMENT AT BRIDGE NO. 98

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FIGURE 35 : DETAILS OF SPUR OF RIVER SHARDA

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