Week 6 Challenge

Aim :

1. To Summarize your study for the bending moment, shear force and deflection diagrams for the raft foundation in stadd and compare them with manual calculation for different set of loads. Fill of 1 m on top slab.

1) Earth pressure 2) self-weight 3) Surcharge 4) 70R load

2. Based on the analysis design the members and outline the thought process in selecting the member sizes along with the raft foundation design.

3. Detailing of reinforcement in the base slab.

Also, what will be the change in shear in base slab if there is

a)5 m fill

b)1 m fill on top of bridge.

Introduction : The given box structure is of 12m clear span and 5.5m clear height with top slab thickness 0.85m, vertical wall thickness 0.9m & base slab thickness 0.9m. Depth of fill in top slab 1m.

Procedure :

1) Staad creation

Results:

Ans 1. Summary

Bending Moment Diagram

Self weight

Earth Pressure

Surcharge on both sides

70 R Loading

Shear force diagrams

Earth Pressure

Self weight

LL Surcharge

70R Loading

Deflection Diagram

Earth Pressure

Self weight

LL Surcharge

70 R loading

Ans 2. Member Design

Ans 3. Reinforcement detail

Shear is base slab if 1m

Shear in base slab for fill 5m