TOPIC- Formwork for Bridge and Centering Of Arch

NAME ENROLL NO.PATEL NIRMAL 131100106036PATEL PRIYANKA 131100106037PATEL Shivani 131100106039PATEL VIRAJ 131100106040PATEL YASH 131100106042

GUIDED BY: Prof. PINANK R. PATEL Prof. MIHIR B. NAIK

CONTENTSCENTERING OF ARCHCENTERING OF BIG ARCHESFALSE WORK FOR BRIDGESSLIP FORMWORK

Centering of an ArchCentering is the temporary structure

required to support brick, stone or concrete work of arch, Dome etc. during its construction .

The centering choice depends upon several factors like ; Shape of ArchSpan of OpeningThickness of SoffitMaterial used in arch construction …etc

Width of the thinner soffit is 10 cm . If the width of the soffit is wider than 10 cm. ,

two ribs suitably spaced & shaped at the Top may be used.

Centering for a wide soffit and bigger span

Centering for big Arches of bridgesFor the construction of big arches, the

centering will be invariably required.factors:-

Nature & type of arch (i.e. span, rise etc…)Foundation conditionsDepth of water , liability to flood, etc…Distance required between support of

centering for the passage of traffic.Size & lengths of timber availableAvailability of labour.

It has Three type,1. Timber truss centering2. Trestle centering3. Steel truss centering

1. Timber truss centering

It is very useful when,The arch provided in deep valleyThe support for centering are to rest in deep

water.The passage of traffic is required.

2. Trestle centering

3. Steel truss centering

It is very useful when,It is impossible to use trestle type centeringDepth of water is moreArches constructed for heavy flood.

False work for BridgesFalse work consists of temporary structure used in

construction to support spanning or arched structures in order to hold the component in place until its construction is sufficiently advanced to support itself.

The construction of falsework in bridges consists ofTimber or concrete foundation padsTimber corbelsSand jacks and wedgesSteel sill beamsTimber or round hollow steel postsSteel cap beamsTimber or steel stringer beams & timber joists.

Causes of failure of false workThe failure may occurs due to

The overloaded of the falseworkThe inadequate designThe lateral instability of a beam

In some cases, the localized flange bending may takes place at the interface between the cap and sill beams and posts.

Pile formwork• The slip formwork

proves to be economical for vertical structures, which are in the form of concrete shafts.

• They are widely used for piers, chimneys, towers, missile, launching bases, water reservoir, silos, revolving restaurants, etc.

The essential parts of slip forms are follow- sheathing- wales or ribs- yokes- working platform or deck- suspended scaffolding-lifting devices

Advantages The construction of joints is eliminated. The construction work can be carried out speedily. There is considerable saving in cost of forms as there is less

wastage of forms and they can be used several times.

ReferenceGoogle imageAdvanced construction Equipments by R.P.

RETHALIYAAdvanced construction Techniques by

Mahajan publication.

Thanks…