DEPARTMENT OF CIVIL ENGINEERING

AHSANULLAH UNIVERSITY OF SCIENCE AND TECHNOLOGY

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Course N0 : CE 416Course Title: Prestress Concrete

Design SessionalCourse Teacher: Munsi Galib

Muktadir Sabreena Nasrin

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Md. Zahidul Islam10.01.03.0024th year 2nd Semester

SUPPORT SYSTEMS Support systems

•Every Structure must have some supports•Restricts free motion of body•Provides stability•Resists or transfers load through a structural system

Support Types

Structures are either partly or completely restrained provided by supports that connect the structure to some stationary body.

There are mainly three types of support:

HingedRollerFixed

Hinged/Pinned Support

Pinned support supplies a reactive force in both vertical and horizontal direction

Doesn’t resist momentAllows rotation but not translationSingle pin support is not sufficient enough to

stable the structureUnknown magnitudes are represented by Rx

and Ry.

Fig: Hinged Bridges

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Hinged Reactions

Roller Support

Roller support supplies a reactive force which acts in a known direction but magnitude is unknown.

Free to rotate and translate along the surfaceCan’t resist momentResulting reaction force is always a single

forceIt can’t provide resistance lateral forcesBuilding structure must have some other type

of supportReaction force is represented by Ry

Fig : Roller Support

Fixed Support

Fixed support encases the member so that rotation and translation is resisted

It can resist horizontal and vertical forces as well as moment

Fixed support stable structures.The forces and moment is expressed by

Rx,Ry,M

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Fixed Support Reactions

Other types

Simple supportLink support

Simple Support

Quite similar to roller supportSingle force is acted perpendicular from the

surfaceUsed in long bridges and roof span

Fig : Simple Support

Link Support

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