Foot bridge presentation

Structural design-II

Prepared by:

Kauswala Tausif k

Structural Design-II syllabus

•RCC DESIGN•STEEL DESIGN

RCC DESIGN

• Loading standards as per I.S & guidelines for the preparation of structural layout.

• Analysis, design & detailing of G+3 RC framed building for residential & commercial Purpose with ductile detailing.

• Design & detailing of underground and elevated water tanks of different c/s.

• Design & detailing of cantilever & counter fort retaining wall

STEEL DESIGN

• Design of bolted / welded plate girder for static and rolling loads.

• Structural layout & Designing of every components of industrial building.

• Design of foot over bridge and structural system of through and deck bridge.

• Design principles for tall steel structures like transmission towers, chimney etc

Topics covered by ME

• Full Steel design –all chapters• RCC design - Analysis, design & detailing of

G+3 RC framed building for residential & commercial Purpose with ductile detailing.

Theories based on foot over bridge

Topics

• When to use truss girders..?• Difference between Plate girder and Truss

girders.• Types of Truss girders• Components of Truss girder.• Loads on Truss girder• Applications of Foot over Bridge

When to use..??

• To carry main load• When load is so large that can not be

economically bridged using plate girders• If span is comparatively large.

Difference

Plate girder• Continuous web• Smaller spans up to

15-24• Elevation is not

good.• More cost

Truss Bridge• Not continuous –

open web having vertical and inclined members.

• Spans upto 30 and more.

• Elevation is good.• Less cost

Types of truss girders

• Through type• Deck type• Semi type/half through

Deck type Bridge

The carriageway rests on the top of the main load carrying members. In the deck type plate girder bridge, the roadway or railway is placed on the top flanges as shown and the cross girders are supported by the trusses generally at the panel points

Through type truss

• - The carriageway rests at the bottom level of the main load carrying members. In the through type plate girder bridge, the roadway or railway is placed at the level of bottom flanges. The bracing of the top flange or lateral support of the top chord under compression is also required.

Semi through type bridge

The deck lies in between the top and the bottom of the main load carrying members. The bracing of the top flange or top chord under compression is not done and part of the load carrying system project above the floor level The lateral restraint in the system is obtained usually by the U-frame action of the verticals and cross beam acting together.

Components of Truss girder bridges

The weight of the truck (and bridge deck) is carried by the stringers into the floor beam and then the floor beam carries this load to the truss at the node point (joint). The bottom chord of the truss is not bent by the weight of the truck because the stringer is attached to the floor beam and not the truss chord.

Loads Applicable on truss girder

The following are the various loads to be considered for the purpose of computing stresses, wherever they are applicable.

Dead loadLive loadImpact loadLongitudinal forceThermal forceWind loadSeismic loadRacking forceForces due to curvature.Forces on parapetsFrictional resistance of expansion bearingsErection forces

Applications of Foot bridge

At railway station to change the platforms

Sky walk in metro

cities

Connecting two

building towers

Busy Streets to cross the

roads

Thank you