Highrise Building design report

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reference report on Highrise Building

Text of Highrise Building design report

  • PG/DIP Structural Engineering Page-1

    Contents

    1. Introduction

    2. Preliminary selection of structural elements

    3. Wind Analysis

    4. Earthquake Analysis

    5. Element Design

    6. Reference

  • PG/DIP Structural Engineering Page-2

    Design of a Forty Story Building for ABC bank head quarts

    1.0 Introduction

    It is decided to design a forty storied building for the use of ABC bank at Colombo 7. Whole

    building is to be used as Bank head quarts and rent some space to be used as office.

    Designed will be done as a part of the course work of Pg Dip /MEng (Structural Design )

    program.

    Key features of the building

    1- 40 storied building

    2- 8 floors to be used as car park

    3- Lift system is designed as Hard Zoning

    4- Building length 48m

    5- Building width 36m

    6- Super structure will be reinforced concrete and sub structure will be pile foundation.

    Following designs will be considered in this Report.

    Decide grid arrangement and building services

    Selecting the arrangement of strong elements

    Selection of suitable loads

    Selection of dynamic parameters

    Determination of wind loads and induced acceleration

    Determination of earth quake loads

    Develop computer model and determination of member forces

    Design of slab beam wall column and pile foundation

  • PG/DIP Structural Engineering Page-3

    1.1 Calculation of basic parameters of the building

    Let Column spacing in longest direction = 8m

    Therefore no of columns 48/8+1 = 7

    Let column spacing in shortest direction = 6m

    Therefore no of columns 36/6+1 = 7

    Let beam height (hb) 6000/14+25 = 450mm

    Slab Thickness (Ts) 6000/44+25 = 160 mm

    Let space for services c = 300 mm

    Let head clearance h = 2.5 m

    Total Floor height h+c+Ts+hb = 2.5+.3+.45

    H = 3.25m

    Height of the Building 3.25x40 = 130m

    Height/Width Ratio 130/36 = 3.6

    One Floor Area 36x48 = 1728 m2

    Lift Core Area 24x16 = 384 m2

    Usable Area = 1344 m2

  • PG/DIP Structural Engineering Page-4

    7

    6

    5

    4

    3

    2

    16.00 m

    6.00 m

    6.00 m

    6.00 m

    6.00 m

    6.00 m

    36.00 m

    48.00 m

    8.00 m

    A B C D E F G8.00 m 8.00 m 8.00 m 8.00 m 8.00 m

    Fig 1 Building Layout

    1.2 Calculation of Number of Lifts

    Let population density = 10 m2

    Number of people per floor 1344/10 = 134.4 per floor

    Let = 135 persons per floor

  • PG/DIP Structural Engineering Page-5

    8th Floor (Car park)

    10th Floor

    20th Floor

    30th Floor

    40th Floor

    Expre

    ss R

    un

    Expre

    ss R

    un

    Hard zoning arrangement will be used as follows.

    Fig 2 Lift Arrangement

    1.2.1 Ground floor level to 19th floor level

    Population calculation Ground floor to 19th floor = 135 x 12

    = 1620 persons

    Let consider serving for 5 minute peak capacity.

    Peak capacity is assumed as 14% of the total population .

    Hence, population handled in 5 minute period = 1620x14/100

    = 226.8persons

    Let 227 persons

    Let select 24 capacity lift, Average interval = 28 sec (Table 25 7.1)

  • PG/DIP Structural Engineering Page-6

    Let select 4m/s speed lift system, hence round trip time = 165 s

    Hence, number of lifts required Round Trip Time

    Average Interval

    = 165 / 28

    = 5.89

    Hence, 6 lift required between ground floor level and 19th floor level.

    1.2.2 20th floor level to 29th floor level

    Population calculation 20th floor to 29th floor = 135 x 10

    = 1350 persons

    Let consider serving for 5 minute peak capacity.

    Peak capacity is assumed as 14% of the total population

    Hence, population handled in 5 minute period = 1350 x 14/100

    = 189 persons

    Let select 24 capacity lift ,Average interval = 32 sec (Table 25 7.1)

    Let select 4m/s speed lift system, for 18 floors hence round trip time = 160 s

    Lift will travel express 6 ms-1 from 8th floor level to 19th floor level and serve 20th floor to 29th

    floor.

    Hence, total distance traveled = 12 x 3.25 x 2

    = 78 m

    Hence, time taken = 78 / 6

    = 13 s

    Total round trip time = 160 + 13 s

    = 173 s

    Hence, number of lifts required = Round Trip Time

  • PG/DIP Structural Engineering Page-7

    Average Interval

    = 173 / 32

    = 5.4

    Say, 5 lifts

    Hence, 5 lift cars to serve between 20th floor level and 29th floor level.

    1.2.3 30th floor level to 39th floor level

    Population calculation 30th floor to 39th floor = 135 x 10

    = 1350 persons

    Let consider serving for 5 minute peak capacity.

    Peak capacity is assumed as 14% of the total population

    Hence, population handled in 5 minute period = 1350 x 14/100

    = 189 persons

    Let select 24 capacity lift ,Average interval = 32 sec (Table 25 7.1)

    Let select 4m/s speed lift system, hence round trip time = 160 s

    Lift will travel express 6 ms-1 from 8th floor level to 29th floor level and serve 30th floor to 39th

    floor.

    Hence, total distance traveled = 22 x 3.25 x 2

    = 143 m

    Hence, time taken = 143 / 6

    = 23.8 s

    Total round trip time = 160 + 24 s

    = 184 s

    Hence, number of lifts required = Round Trip Time

  • PG/DIP Structural Engineering Page-8

    Average Interval

    = 184 / 32

    = 5.7

    Say 6 lifts

    Hence, 6 lift cars can be used to serve between 30th floor level and 39th floor level.

    Summary of the lift arrangement as follows.

    Location No of lifts

    Ground floor level to 19th floor level 6

    20th floor level to 29th floor level 5

    30th floor level to 39th floor level 6

    Total 17

    Table 1 Required lift at each zone

    1.2.4 Lift cabin arrangement

    From Table 25.3

    Cabin size of the 24 passenger lift = 2100 x 1650

    Shaft size = 2550 x 2400

    1.2.5 Stair case arrangement

    Width = 2m

    Length = 3.35m

    Landing length = 4m

    Landing width = 1.5m

    Required opening area = (3.35+1.5)x 4 m2

    = 19.4m2

  • PG/DIP Structural Engineering Page-9

    1.2.6 Wash rooms arrangement

    There will be two washrooms for men and women, 7.5m x7.5m each

    1.2.7 Service Core Arrangement

    Length = 24m

    Width = 16m

    Fig 3 Service Core Arrangements

    men

    wash room

    ladies

    wash room

    7

    6

    5

    4

    3

    2

    16.00 m

    6.00 m

    6.00 m

    6.00 m

    6.00 m

    6.00 m

    36.00 m

    48.00 m

    8.00 m

    A B C D E F G8.00 m 8.00 m 8.00 m 8.00 m 8.00 m

  • PG/DIP Structural Engineering Page-10

    men

    wash room

    ladies

    wash room

    7

    6

    5

    4

    3

    2

    16.00 m

    6.00 m

    6.00 m

    6.00 m

    6.00 m

    6.00 m

    36.00 m

    48.00 m

    8.00 m

    A B C D E F G8.00 m 8.00 m 8.00 m 8.00 m 8.00 m

    1.2.8 Shear wall arrangement

    Lateral loads are to be resisted by a shear wall arrangement.

    Assumed Shear wall thicknesses are as follows.

    Zone Selected Shear wall

    thickness / (mm)

    Ground to 9th floor level 300

    10th floor to 19th floor level 300

    20th floor to 29th floor level 300

    30th floor to 39th floor level 300

    Table 2 Shear wall Thickness

    Fig 4

    Shear wall

    arrangement

  • PG/DIP Structural Engineering Page-11

    2.0 Preliminary selection of structural elements.

    Slab Thickness

    Selected slab thickness = 175 mm

    Cover = 25 mm

    Diameter of the reinforcement = 10 mm

    Hence, effective depth = 175 - 25 10/2

    = 145 mm

    Span / Effective depth = 6000 / 145

    = 41.4

    Basic span / Effective depth = 26 ( T 3.9 BS8110)

    Let Assume a modification factor of 1.6

    Modified span / Effective depth = 26 x 1.6

    = 41.6

    Hence, 175 mm slab thickness is capable of meeting the deflection criteria satisfactorily.

    2.1 Selection of Beam Dimensions

    Selected beam depth = 600 mm

    Hence, effective depth = 550 mm

    Span / Effective depth = 8000 / 550

    = 14.55

  • PG/DIP Structural Engineering Page-12

    2.2 Determination of Column Dimensions

    Initial column size can be selected with trial approximate loads

    Assume column carries load from 8 x 6 panel area of the building. Trial size of column will be

    selected according to axial load capacity

    2.2.1 Dead loads calculation

    Slab self-weight = 8 x 6 x 0.175 x 24

    = 201.6 kN

    Assuming Finishes of 0.75 kN / m2 = 0.75 x 8 x 6

    = 36kN

    Assuming partition of 1.0 kN / m2 = 1.0 x 8 x 6 (BS 6399 5.1.4)

    = 48 kN

    Assuming services of 1.0 kN / m2 = 1.0 x 8 x 6

    = 48 kN

    Beams Weight = (8 + 6) x 0.4 x 0.6 x 24

    = 80.64 kN

    Live load on slab of2.5 kN / m2 = 2.5 x 8 x 6 (BS 6399)

    = 120 kN

    Calculation of desig