Week 7 Challenge

AIM OF THE EXPERIMENT: To determine the water current loads acting on bridge and perform analysis accordingly in Staad Pro.

THEORY:-

Water Current Load:- A Water Current Load is the amount of stream water that is passed from a catchment to the component receiving at the substructure of bridge.

Objective:-

The objective is to calculate water current loads from the given data and apply it in Staad.Pro for the bridge and analyse the results and effects on the structure.

Given Data:-

Span of the Bridge :- 2x45m

HFL:- 2m above the foundation level

Assumption:

Size of Pier = 2m Diameter

Size of Abutment = 2m Diameter

Size of Cross-beam = 1m x 1m

Girder Type :- I-Section

Thickness of Deck slab = 300 mm

Width of bridge = 10.0 m.

CALCULATION:-

Height of piers & Abutments subjected to water current = 2 m

Vmean= 3 m/s

Maximum Velocity = V = √2 x Vmean= √2 x 3 = 4.243 m/s

Water current pressure = P = 0.52 x k x V²

As Piers are circular in shape, So, value of k = 0.66

P = 52 x 0.66 x (4.243)² = 617.865 KN/m²

Procedures in Staad Pro.

STEP 1:-

Model the Bridge in Staad Pro. As per given question and assumptions with proper dimensions.

STEP 2:-

Create mesh elements for the deck slab of unit mesh size 0.m x 0.5m

STEP 3:-

Give the property for abutments, piers, girders , cross beams and deck slab

• FOR ABUTMENT AND PIERS

• FOR GIRDERS

• FOR CROSS BEAMS

• FOR DECK SLAB

STEP 4:-

Create and assign Supports for the bridge

STEP 5:-

Applications of Loadings

1. Dead loads
2. Water current loads

For Self weight,

For water current loads in z direction:-

Water current loads in x directions:-

STEP 6:-

Go to Analysis/Print/select no print

Go to Analyze menu bar, select perform analysis

Step 7:-

Go to Post Processing Mode:-

Support Reactions for DL

Support Reactions for water current z-dir.

Support reactions for water current in x direction

Plate contours on My local on water current on z direction