View
329
Download
35
Category
Tags:
Preview:
Citation preview
5/21/2018 Design of Box Culvert(FINAL)
1/12
Designed By: Date:
Verified By: Revision:
Version 1
INPUT DATA
CONCRETE COMPRESSIVE STRENGTH, f 'c 28 MPA
REBAR YIELD STRENGTH, fy 420 MPA
CONCRETE UNIT WEIGHT, gc 24 kN/cum
SATURATED SOIL UNIT WEIGHT, gs 18 kN/cum
HEIGHT OFCULVERT, H 4300 mm
WIDTH OF CULVERT, B 6900 mm
THICKNESS OF SIDE WALLS, tw 450 mm
THICKNESS OF TOP SLAB, tts 500 mm
THICKNESS OF BOTTOM SLAB, tbs 600 mm
DEPTH OF FILL, hf 2800 mm
IMPOSED SERVICE DEAD LOADS, wd 3.83 KPa
ALLOWABLE SOIL PRESSURE, Qa 96 KPa
SOIL ANGLE OF FRCITION, 30 Deg.
PREFERRED REBAR SIZE 16 mm
CONCRETE COVER TO REBAR CENTER 75 mmNO. OF REINFORCEMENT LAYERS 2 Shear Status O.K.
MAIN REINFORCEMENT SPACING 150 mm Flexure Status O.K.
TEMPERATURE REINFOR. SPACING 300 mm Soil Pressure Status O.K.
LOADS ON THE CULVERT
For the design purposes a one-meter length of the culvert is considered.
Top Slab
Vehicular Live Loads (HS 20 AASHTO Truck)
Include live loads if hf< 2400mm hf= 2800 mm LL ignored. Design Based on (AASHTO 3.6.1.2
Multiple presence factor 1.20 Traffic travelling parallel to span (AASHTO 3.6.1.1
Width of distributed load (parallel to span) 0 mm (AASHTO 3.6.1.2
Length of distributed load (perpend. to span) 0 mm Equiv. wheel loads don't overlap. (AASHTO 3.6.1.2
Pressure intensity at the specif ied depth of fi ll 0.00 KPa Wheel Load = 72.5 KN
Linear load on the top slab 0.00 KN/m Assumed to act on full width of the slab.
Dynamic Load Allowance (Impact Factor) (AASHTO 3.6.2.2)
IM = 33(1 - 0.00041 hf) > 0% 0.00 % Factor for increasing live load due to impact effects
Increased linear live load 0.00 KN/m Impact and multiple presence factor included.
Weight of earth fill
Linear weight of fill on the slab 50.40 KN/m
Imposed dead loads
Linear imposed dead loads on the slab 3.83 KN/m
Selfweight
Linear selft weight of the slab 12 KN/m
Side Walls
Soil pressure
kah= (1 - sinf) / (1 + sinf) 0.333Surcharge on side walls due to top soil 50.4 KPa
STRUCTURAL DESIGN OF SINGLE CELL BOX CULVERT
Based on AASHTO LRFD Bridge Design 2007 SI
Job Name/Station: Pedestrian Underpass/3391 IDREES/FARHAN NILL
Client: C & W Department IDREES/FARHAN 9-Jul-12
Design Summary
5/21/2018 Design of Box Culvert(FINAL)
2/12
(cont'd
Height of surcharge (h' = s / gs ) 2.8 m
Linear pressure at the bottom of the side wall 42.6 kN/m
Selfweight
Two side walls = tw(H - tbs - tts) gc 69.1 KN
Bottom Slab
Self weight of the whole structure
Linear soil pressure due to stru. selfweight 90.6474 kN/m See note 1
Vehicular Live Loads (HS 20 AASHTO Truck)
Linear soil pressure due to live loads 0.00 KN/m See note 1
FACTORED LOAD DIAGRAMS
Load factor for dead load 1.25 (AASHTO 3.4.1)
Load factor for horizontal earth pressure 1.50 (AASHTO 3.4.1)
Load factor for live load 1.75 (AASHTO 3.4.1)
82.79 0.00
25.20 25.20
63.9 63.9
113.30924 0.00
ANALYSIS OF THE STRUCTURE
The structure is analyzed using the moment distribution method.
The fixed-end moment at each joint is the superposition of the fixed-end moments due to dead, live and earth pressure loads.
Joint A B D C
Member AC AB BA BD DB DC CD CA
Length 3.20 6.90 6.90 3.20 3.20 6.90 6.90 3.20
Moment of Inertia 0.0375 0.0417 0.0417 0.0375 0.0375 0.0500 0.0500 0.0375
Distrib. Factor 0.66 0.34 0.34 0.66 0.62 0.38 0.38 0.62
FEM 34.71 -328.46 328.46 -34.71 41.32 -449.55 449.55 -41.32
Distribution 193.85 99.89 -99.89 -193.85 252.25 155.98 -155.98 -252.25
Carry Over -126.13 -49.95 49.95 126.13 -96.93 -77.99 77.99 96.93
Distribution 116.20 59.88 -59.88 -116.20 108.08 66.83 -66.83 -108.08
Carry Over -54.04 -29.94 29.94 54.04 -58.10 -33.42 33.42 58.10
Distribution 55.42 28.56 -28.56 -55.42 56.55 34.97 -34.97 -56.55Carry Over -28.27 -14.28 14.28 28.27 -27.71 -17.48 17.48 27.71
Distribution 28.08 14.47 -14.47 -28.08 27.93 17.27 -17.27 -27.93
Carry Over -13.96 -7.24 7.24 13.96 -14.04 -8.63 8.63 14.04
Distribution 13.99 7.21 -7.21 -13.99 14.01 8.66 -8.66 -14.01
Carry Over -7.01 -3.60 3.60 7.01 -6.99 -4.33 4.33 6.99
Distribution 7.00 3.61 -3.61 -7.00 7.00 4.33 -4.33 -7.00
Carry Over -3.50 -1.80 1.80 3.50 -3.50 -2.16 2.16 3.50
Distribution 3.50 1.80 -1.80 -3.50 3.50 2.16 -2.16 -3.50
Moment Sum 219.85 -219.85 219.85 -219.85 303.37 -303.37 303.37 -303.37
5/21/2018 Design of Box Culvert(FINAL)
3/12
5/21/2018 Design of Box Culvert(FINAL)
4/12
SHEAR MOMENT DIAGRAMS
Top Slab
Mmax (+) 272.84 kN/m
Mmax (-) -219.85 kN/m
Design Moment 272.84 kN/m
Vmax (+) 285.62 kN
Vmax (-) -257.06 kN
Design Shear 213.18 kN
At distance d from the face of the support
Bot tom Slab
Mmax (+) 303.37 kN/m
Mmax (-) -370.96 kN/m
Design Moment 370.96 kN/m
Vmax (+) 390.92 kN
Vmax (-) -390.92 kN
Design Shear 280.44 kN
At distance d from the face of the support
-300.0
-200.0
-100.0
0.0
100.0
200.0
300.0
0.
00
1.
04
2.
07
3.
11
4.
14
Moment(kN
-m)
Distance x (m)
Top Slab Moment Diagram
-400.0
-300.0
-200.0
-100.0
0.0
100.0
200.0
300.0
400.0
0.
00
1.
04
2.
07
3.
11
4.
14
Shear(kN)
Distance x (m)
Top Slab Shear Diagram
-500.0
-400.0
-300.0
-200.0
-100.0
0.0
100.0
200.0
300.0
400.0
0.
00
1.
04
2.
07
3.
11
4.
14
Moment(kN-m)
Distance x (m)
Bottom Slab Moment Diagram
-500.0
-400.0
-300.0
-200.0
-100.0
0.0
100.0
200.0
300.0
400.0
500.0
0.
00
1.
04
2.
07
3.
11
4.
14
Shear(kN)
Bottom Slab Shear Diagram
5/21/2018 Design of Box Culvert(FINAL)
5/12
500.0
Side Walls
Mmax (+) 303.37 kN/m
Mmax (-) -176.84 kN/m
Design Moment 303.37 kN/m
Vmax (+) -81.91 kN
Vmax (-) -184.15 kN
Design Shear 168.49 kN
At distance d from the face of the support
THICKNESS CHECK
Shear strength provided by concrete = fVc= f0.17 (f'c)0.5
bwd
Component d (mm) fVc kN) Vd (kN) StatusTop slab 425 286.7 213.2 O.K.
Bottom slab 525 354.2 280.4 O.K.
Side walls 375 253.0 168.5 O.K.
REINF. CALCULATIONS
Minimum reinforcement ratio for main reinforcement, min 0.0006 See note 2
Minimum reinforcement ratio for temperature reinforcement, min 0.0008 See note 2
Maximum center to center spacing of reinforcement, smax 900 mm Max (1.5 t, 450)
d (mm) Mu(kN-m) As (mm2) As prov act min Status act min
Top slab 425 303.2 1887 2681 0.0054 0.0012 O.K. 0.0054 0.0017
Bottom slab 525 412.2 2077 2681 0.0045 0.0012 O.K. 0.0045 0.0017
Side walls 375 337.1 2378 2681 0.0060 0.0012 O.K. 0.0060 0.0017
SOIL PRESSURE CHECK
Pressure on soil 90.65 KPa
Allowable soil pressure 96.00 KPa
Status O.K.
1- In reality, the uplift soil pressure on the bottom slab may not be uniform. However, for simplicity, it shall be assumed to be uniform.
2- Minimum reinforcement ratio found is for one layer of reinforcement and shall be multiplyed by 2 if there is 2 layers of reinforcement
TEMPRATURE RComponent
MAIN REINFORCEMENT
-300.0
-200.0
-100.0
0.0
100.0
200.0
300.0
400.0
0.
00
0.
48
0.
96
1.
44
1.
92
2.
40
Moment(kN
-m)
Distance x (m)
Side Walls Moment Diagram
-200.0
-180.0
-160.0
-140.0
-120.0
-100.0
-80.0
-60.0
-40.0
-20.0
0.0
0.
00
0.
48
0.
96
1.
44
1.
92
2.
40
Shear(kN)
Distance x (m)
Side Walls Shear Diagram
5/21/2018 Design of Box Culvert(FINAL)
6/12
2 Minimum reinforcement ratio found is for one layer of reinforcement and shall be multiplyed by 2 if there is 2 layers of reinforcement.
this design spreadsheet can not be used since it is possible that two axle loads come on the culvert.
5/21/2018 Design of Box Culvert(FINAL)
7/12
5/21/2018 Design of Box Culvert(FINAL)
8/12
5/21/2018 Design of Box Culvert(FINAL)
9/12
5/21/2018 Design of Box Culvert(FINAL)
10/12
5/21/2018 Design of Box Culvert(FINAL)
11/12
5/21/2018 Design of Box Culvert(FINAL)
12/12
Recommended