Project 2

AIM  : Calculate the water current forces ,centrifugal forces, wave forces, snow loads, temperature loads, Barge Impact load for the bridge structure shown. Analysis of model using Staadpro useing required IS codes and IRC codes 

INTRODUCTION : 

• This is 2nd project of first module of Design of loads considered on bridge 
• In this challenge I have to apply the water current forces ,centrifugal forces, wave forces, snow loads, temperature loads, Barge Impact load
• Bridge is located at a river bed 

GIVEN DATA

The high flood level is 4 m above the Bottom of foundation level. The span of the bridge is  10 m.

○The mean velocity of the river is 2.5 m/s.

○Width of carriage way is 9 m.

○The bridge is subjected to a live load of Class 70R tracked vehicle and radius of curvature in the bridge is 2 m.

○The design speed of the vehicles is 50 km/hr.

○The size of the Pier is 1.2 x 1.2 m.

○The width of deck slab is 10.5m and the thickness of deck slab is 1.5 m. The deck of bridge is flat with B <30>

○The Dead weight tonnage of Panamax vessel is 25000 DWT. The Ship can accommodate maximum of 1500 containers. Each container is of standard 6.1 TEU.

 The maximum crest elevation for the wave is 3 m.

 The deck of the slab is supported by four I Girders. Each I Girder is 1.6 m height with a top and bottom flange width of 2m. The thickness of flange and web is 0.3m

. Assume constant r as 5. Assume Cva as 3. The Storm elevation is 8.5m. Take Cr as 0.4

MODEL MAKING : 

PIERS CREATION : 

• Open Staadpro and create a file 
• Add a node and copy it in Y direction at 12m height of pier connect this two nodes by adding abeam between them 
• copy the created beam copy it in Z direction at 3.5m 3 steps using translational repeat 
• Select the created 4 piers and copy it in X direction at 10m distance and  4 steps then 40m span will be creted 

 GIRDERS  CREATION :

• Click on add beam and add a beam between piers 
• Add also cross girdeas shown in below

• 

DECKSLAB CREATION :

• Select a corner node and copy it in X direction and select those 2 nodes and copy it in x direction
• Click on add plate and add a plate  between those nodes 
• Copy this plate to Create a deck slab 
• as shown inn below

SUPPORT CREATION : 

• Click on supports and add afixed supports to all the piers 
• as shown inn below 

now our model is successfully created 

PROPERTIES :

• FOR DECK SLAB ADD APLATE THICKNESS OF 1.5m AS SHOWN IN BELOW

• FOR GIRDER GIVE THE PROPERTY AS SHOWN IN GIVEN DATA 

• AFTER APPLYING ALL THE PROPERTIES OUR STRUCTURE LOOKS LIKE AS SHOWN IN BELOW 

LOAD APPLICATION :

• WATER CURRENT LOADS 

HFL = 4m 

mean velocity  2.5m/s 

pier size = 1.2 x 1.2 m 

as per IRC 6 to calculate the water current forces formula is 

P = 52KV^2

v = max velocity = √2 x 2.5 = 3.53m/s

K = 1.50 for square ended piers 

P = 52 X 1.50 x 3.53^2

   = 971.95kg/m3

P = 9.71 kn/m2 

Click on load case details = add a load case = water current force = add trapezoidal load in local z direction = wnter value and load is upto 4m above foundation = assign the load as shown in below 

• CENTRIFUGAL FORCES :

Span = 10m 

width = 10.5m

live load of class 70R tracked vehicle 

radius of curvature = 2m 

design speed = 50km/h 

weight = 700kn 

Centrifugal force = (W x v^2)  /  127 R 

                            =  (700 x 50 x 50 )/ 127 x 2 

                            = 6889.76 kn 

Assumed load generation is 60 

• Click on load defination and add a load = click on load case details = add load generation 60 assign the load to the structure as shown in below 
•  
• 
•  
• 

• WAVE LOADS : 

max crest = 3m

r = 5 

assume 

Cva = 3 

Cr = 0.4 

Storm elevation : 8.5m  

Fv =  Gamma x delta zv x Av 

    = 10 x 1.9 x 420 

    = 7980 kn 

Fh = gamma x deltazv X Ah 

     = 10 x 1.7 x 104 

     = 1768 kn 

Fv max = Cva - vfv = 3 x 7890 = 23940 kn 

            = 23940 / 420 = 57kn 

Fhmax = (1 + cr(n-1)cva-h X Ah ) = 11668.8 kn / 104 = 112.2kn

• SNOW LOAD ; 

B < 30>

Depth = 1250mm

width = 10.5m 

thickness of deck = 1.5m

we are asumming that snow is settled snow 

so density = 3kn/m3 

So = Density X Depth X span = 3 x 1.25 x 40 = 150kn/m 

u = 0.8 

Design snow load = 0.8 x 150 = 120kn/m 

• Temperature loads : 

Assuming the city of delhi 

grade of concrete = M20 grade 

Max temp in location as per IRC 6 isothern at location = 47.5 degree 

Min temp in location as per IRC 6 isothern at location = -2.5 degree 

Effective temp difference = 47.5 - (-2.5) + 10 / 2 = 25 + 10 = 35 degree 

Stresss due to temp = 11.27 x 10^-6 x 35 x 5000root 40 = 12.47 kn/m2 

max permissible stres = 2/3 x 0.7 x root40 = 2.95 kn/m2 = 3kn/m2 

• positive temp difference = 5.60 degree 
•  
• 

• BARGE IMPACT LOAD : 

Barge impact energy = 3014564063

Barge damage depth = 58346.76mm 

Barge Collision impact force = 99354832kn 

Uniform force = 2483.87kn/m

Analysis And Result :