Week 5 Challenge
Aim: To calculate the Design wind load on the bridges
INTRODUCTION:- This challenge is focusse on how to apply the wind load on the bridges using the stadd pro software. This study will provide the step by step procedure of designing the deck slab, girder, cross beam and column.
LIVE LOAD CALCULATION:-
Height of bridge from G.L = 9 m
Vb = 44 m/s (Mumbai)
K1 = 1.07
K2 = 1.05
K3 = 1
K4 = 1.3
Vz = Vb*k1*k2*k3*k4
= 44*1.07*1.05*1*1.3
= 64.26 m/s
Wind Pressure, Pz = 0.6 Vz*Vz
= 0.6*64.26*64.26
= 2.477 KN/m2
For 9 m, Pz = 2.477*9
= 22.29 kn/m
PROCEDURE:-
- Step 1 :- Analytical Modelling
- Firstly nodes were created. Then after creating nodes the deck slab and column height of 9 m is modelled.
- Creating mesh side of 0.5 m x 0.5 m through out the length of the bridges.
- Defining the section properties of the bridges like thickness of deck slab and pier, girder and cross beam. And then after defining the section properties of the pier
- Creating fixed support at the base of pier
- LOADING:- First i apply the self weight of bridge as -1 by selecting the bridge. and then after that wind load is applied in +X, -X, +Z and in -Z direction.
Figure 3D model of the designed bridge
Figure Applied wind load in +X direction
ANALYSIS
1. STATIC CHECK: Firstly static check is done in which the difference between the load and reaction shoukd be zero. static check is ok.
Figure Static check
DEFLECTION :- Maximum deflection is 0.448 mm
Figure Deflection
2. REACTION
Reaction due to wind in +X Direction (First row Pier) 2nd Row Pier 2rd Row Pier
X = 149.051 KN X = 37.702 KN X = 29.476 KN
Y = 20.432 KN Y = 9.849 KN Y = 31.198 KN
Z = 0.002 KN Z = 0.044 KN Z = 0.260 KN
Mx = 0.225 KN-m Mx = 0.106 KN-m Mx = 1.007 KN-m
My = 1.329 KN-m My = 0.680 KN-m My = 1.098 KN-m
Mz = 392.342 KN-m Mz = 207.394 KN-m Mz = 182.898 KN-m
Figure Reaction due to wind in +X
Reaction due to wind in -X Direction (First row Pier) 2nd Row Pier 2rd Row Pier
X = 29.476 KN X = 37.702 KN X = 149.190 KN
Y = 31.198 KN Y = 9.849 KN Y = 21.508 KN
Z = 0.260 KN Z = 0.044 KN Z = 0.027 KN
Mx = 1.007 KN-m Mx = 0.106 KN-m Mx = 0.225 KN-m
My = 1.098 KN-m My = 0.680 KN-m My = 1.329 KN-m
Mz = 182.898 KN-m Mz = 207.394 KN-m Mz = 392.342 KN-m
Figure Reaction due to wind in -X direction
Reaction due to wind in +Z Direction (First row Pier) 2nd Row Pier 2rd Row Pier
X = 0.133 KN X = 0 KN X = 0.133 KN
Y = 27.908 KN Y = 28.440 KN Y = 27.908 KN
Z = 134.644 KN Z = 134.578 KN Z = 134.644 KN
Mx = 304.316 KN-m Mx = 303.850 KN-m Mx = 304.316 KN-m
My = 0.439 KN-m My = 0 KN-m My = 0.439 KN-m
Mz = 0.372 KN-m Mz = 0 KN-m Mz = 0.542 KN-m
Figure Reaction due to wind in +Z Direction
Reaction due to wind in -Z Direction (First row Pier) 2nd Row Pier 2rd Row Pier
X = 0.133 KN X = 0 KN X = 0.133 KN
Y = 27.908 KN Y = 28.440 KN Y = 27.908 KN
Z = 134.644 KN Z = 134.578 KN Z = 134.644 KN
Mx = 304.316 KN-m Mx = 303.850 KN-m Mx = 304.316 KN-m
My = 0.439 KN-m My = 0 KN-m My = 0.439 KN-m
Mz = 0.372 KN-m Mz = 0 KN-m Mz = 0.542 KN-m
PLATE STRESSES:- Due to +ve X Direction
Mx = -2.21666 KN-m/m (minimum) and Mx = 1.92849 KN-m/m (maximum)
My = 0.445127 KN-m/m (maximum) and Mx = -0.442241 KN-m/m (minimum)
Mxy = 0.354346 KN-m/m (maximum) and Mxy = -0.354346 KN-m/m (minimum)
Sqx = 0.000647223 N/mm2 (maximum) and Sqx = -0.0155573 N/mm2 (minimum)
Sqy = 0.00329324 N/mm2 (maximum) and Sqy = -0.00329324 N/mm2 (minimum)
Figure Maximum plate stresses due to +X wind (maximum moment)
PLATE STRESSES:- Due to -ve X Direction
Mx = -2.21666 KN-m/m (minimum) and Mx = 1.92849 KN-m/m (maximum)
My = 0.445127 KN-m/m (maximum) and Mx = -0.442241 KN-m/m (minimum)
Mxy = 0.354346 KN-m/m (maximum) and Mxy = -0.354346 KN-m/m (minimum)
Sqx = 0.0155573 N/mm2 (maximum) and Sqx = -0.000647224 N/mm2 (minimum)
Sqy = 0.00329324 N/mm2 (maximum) and Sqy = -0.00329324 N/mm2 (minimum)
PLATE STRESSES:- Due to +ve Z Direction
Mx = 0.118345 KN-m/m (maximum) and Mx = -0.147824 KN-m/m (minimum)
My = 0.484466 KN-m/m (maximum) and Mx = -0.657576 KN-m/m (minimum)
Mxy = 0.295793 KN-m/m (maximum) and Mxy = -0.295793 KN-m/m (minimum)
Sqx = 0.00326652 N/mm2 (maximum) and Sqx = -0.00326652 N/mm2 (minimum)
Sqy = 0.0017222 N/mm2 (maximum) and Sqy = -0.0156602 N/mm2 (minimum)
Figure Maximum plate stresses due to +Z wind (maximum moment)
GIRDER FORCES CALCULATION
Mz = 82.932 KN-m
My = 6.765 KN-m
Fy = 26.023 KN
Fz = 8.80 KN
Figure Maximum moment in Girder (Mxy)
CROSS BEAM FORCES CALCULATION
Mz = 72.835 KN-m
My = 1.652 KN-m
Fy = 26.828 KN
Fz = 2.790 KN
Figure +X Wind loading Diagram
PIER FORCE CALCULATION
Mz = 392.342 KN-m
My = 304.316 KN-m
Fz = 134.644 KN
Fy = 149.051 KN
Figure Maximum moment in pier (Mz)
Figure Maximum shear in diagram (Fy)