Assign Group Stairs

7/30/2019 Assign Group Stairs

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Type Of Stairs

Wood

Brick

StoneSteel

Concrete

Combination of thematerials


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Characteristic Of Stairs

Non-combustible materials

Comfortable

Safety follow the rulesStairway protected by a fire-resistingenclosure.

Limitations as to riser height, tread lengths

and handrail requirement usually based uponuse the building


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Single Straight Flight Stairway


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Simple in design and construction, can be unpopular because ofthe plan space it occupies.

The flight behaves as a simply supported slab planning fromlanding and landing.

The effective span or total horizontal going usually taken asbeing from landing edge to edge by providing a down stand edgebeam to each landing.

Edge beam are not provided the effective span would be takenas overall of the landing.

Resulting in a considerably bending moment and hence more

reinforcement.


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Inclined Slab Stair With Half-Space Landing


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Usually plan format for reinforcement concrete stair giving a morecompact paln layout and better circulation than the single straightflight stairs.

The haft space(180)turn landing is usually introduced at the mid-

point of the rise giving equal flight spans.Reducing the effective span and hence the bending momentconsiderably.

Design the landing span crosswise into a load bearing wall.

Tension lap required at the top and button of each flight toovercome the tension included by the tendency of the internal

angles of the junction.


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Staring Beam Stairs


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Alternative design for the stairs described above.

Edge beam is used to span from landing to landing to

resist the banding moment.

Result in a thinner waist dimension and an overall

saving in the concrete volume require.

The staring beams can be either up stand or down

stand in format and to both sides.


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Cranked Slab Stairs


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Very often used as a special feature since the haft space landinghas no visible support.

Bending, buckling and tension stress are included with this formof design creating the need for reinforcement to both faces of thelanding.

Slab or waist of the flight, indeed the amount or reinforcementrequire can sometimes create site problem with regard to placingand compacting the concrete.

Typical details of a cranked slab stairs, which is also known ascontinues stairs, scissor stairs or jack-knife stairs.


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Cantilever Stairs (Spine Wall Stairs)


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Central vertical wall from which the flight and haftspace landing are cantilever.

The wall provides a degree of fire resistance betweenthe flight and are therefore used mainly for escapestairs.Since both flight and landings are cantilever thereinforcement is placed in the top of the flight slab.

Upper structure of the landing to counteract theinduced negative bending moments.


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Spiral Stairs


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Used mainly as accommodation stairs in the foyers of prestigebuildings such as theatres and blanks.

Can be expensive to construct, being normally at least seven times thecost of conventional stairs.

The plan shape is generally based on a circle although it is possible to

design.Can be formed around a central large-diameter circular column in asimilar manner.

Tension and compressive stresses are included in this form of stairsway which will require reinforcement to both faces of the slab.

Formwork for spiral stairs consists of a central vertical core or barrel to

form the open stairs well to which the so fit and riser boards are set outand fixed.


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Precast concrete stair

Better quality control of the finished product.

Saving in site space, since formwork storage and fabricationspace are no longer necessary.

Stairway enclosing shaft can be utilized as a space for hoistingor lifting materials during the major construction period.

Can usually be positioned and fixed by semi-skilled operatives.


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Precast Concrete Straight Flight Stairs.


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Spanning between landing can have a simplebearing or, by leaving projecting reinforcement to begrouted into preformed slots in the landings.

Straight flight precast concrete stairs with a simplebearing require only bottom reinforcement to the slaband extra reinforcement to strengthen the bearing ornib.

The bearing location is a rebate cast in the in-situfloor slab or landing, which is filled with a

compressible material to form a flexible joint.


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CRANKED SLAB PRECAST CONCRETE STAIR


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Usually formed as an open well stairway.

The bearing for the pre-cast landings to the in-situ floor or to thestructural frame is usually in the form of a simple bearing

The infill between the two adjacent flight , in an open well planarrangement at floor and intermediate landing levels.

It must be remembered that when pre-cast concrete stair flightare hoisted into position, different stresses may be includedfrom those which will be encountered in the fixed position.

To overcome this usual ,provide definite lifting points in theform of the projecting lugs or by utilizing any holes cast in to

received the balustrade.


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Precast Concrete Open Riser Stairs.


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Are a form of stairs which can be both economic and attractiveconsisting of a central spine beam in the form.

The foot of the lowest spine beam is located and floor levels.

Anchor bolts or cement in sockets are cast into the spine beam

to provide the fixing for the cantilever. The support for the balustrade and handrail are located in hole

formed at the ends of the treads and secured with a nut and

washer on the underside of the tread.


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Precast Concrete Spiral Stairs.


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Work are based upon the stone stairs found in manyhistoric buildings such as Norman castle andcathedrals.

Holes are formed at the extreme ends of the treads,

to receive the handrail supports in such a mannerthat the standard passes through a tread and is fixedto the underside of the tread immediately below.

A hollow spacer or distance piece is usuallyincorporated between the two consecutive treads.


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Steel Escape Stairs .


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These have already been considered in the contextof means of escape in case of fire and a typicalgeneral arrangement is illustrated.

The treads for this type of stair are bolted to the

strings and can be of a variety of types ranging fromperforated cast iron to patterned steel.

Handrail balustrades or standards can be of steelsquare or tubular sections bolted to the upper surfaceof a channel string or to the side of a channel or

steel plate string.


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Steel Spiral Stairs .


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These may be allowed as an internal or externalmeans of escape stairs if they are to accommodateno more than 50 persons.

Spiral stairs give a very compact arrangement andcan be the solution in situations where plan area islimited.

Two basic forms are encountered, namely those withtreads which project from the central pole or tube andthose which have riser legs.


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OTHER STAIR


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CONCLUSION.

Have so many type of stairs, for example wood, brick,stone, steel, Concrete and Combination of the material. Thistype will be design with follow the place where the stair erected.The main function of stairs is for give easily to user for up anddown in the building. Good characteristic that usually have in

stairs is Non-combustible materials, comfortable, safety followthe rules, stairway protected by a fire penetration and limitationsas to riser height, tread lengths and handrail requirement usuallybased upon use the building.

Assign Group Stairs

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