conjunction with this code, allowable bending stresses in compression (FCY Table 11CIndian Steel Design IS Parameters. The design concept is totally changed in comparison to earlier code IS which is based on Elastic method. In view of this, an effort has. Now this time I am come with IS code of Design of Steel Structure. This code is allowed for Polytechnic Diploma in Civil, lesforgesdessalles.info
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Is (Rerfflrmed ). Indian Standard. CODE OF PRACTICE FOR. GENERAL CONSTRUCTION, IN STEEL. (First Revision). Sixtcmtb Reprint MAY . Scope of IS Indian Standard Code. IS Indian Standard applies to general construction using hot rolled steel sections joined using riveting, bolting and welding. This Indian Standard (Third Revision) was adopted by the Bureau of Indian Standards after the draft. IS - Download as PDF File .pdf), Text File .txt) or read online. Indian Standard CODE OF PRACTICE FOR GENERAL CONSTRUCTION IN STEEL.
The provisions of Section 11 with respect to workmanship shall govern the fabrication of structures. Mona Awad. Damaged or deteriorated paint surfaces shall first be made good with the same type of paint as the shop coat. Structures or portions of structures proportioned using plastic design shah have sufficient strength as determined by plastic analysis to support the working loads multiplied by load factors as given below: When the web is subjected to bending and compression. In no case shall a tie plate and its fastenings be incapable of carrying the forces for which the lacing has been designed. Roorkee Engineers India Ltd.
Where single stiffeners are used. Intermediate vertical stiffeners may be joggled and may be single or in pairs placed one on each side of the web. I and t are as defined in 6. The stiffeners shall extend from flange to flange.
When vertical intermediate stiffeners are subjected to bending moments and shears due to eccentricity of vertical loads. For stiffeners subjected to external. Intermediate vertical and horizontal stiffeners not subjected to external loads shall be connected to the web by rivets or welds.
Tn addition to the requirements of 6. Load bearing possible. The radius of gyration shall be taken about the axis parallel to the web of the beam or girder. The stiff portion of a bearing is that length which cannot deform appreciably in bending and shall not be taken as greater than half the depth of beam for simply supported beams and the full depth of the beams continuous over a bearing.
For any section.
The design and detailing of box girders shall be such The diaphas to. At points of support this requirement shall apply. Stiffeners shall be symmetrical about the web. The ends of load bearing stiffeners shall be fitted to provide a tight and uniform bearing upon the loaded flange unless welds or rivets designed to t ansmit the full reaction or load are provided between the flange and stiffener.
The bending stresses about the two axes should be determined separately and Open web purlins shall be designed as checked in accordance with 7. As an alternate to the general design procedure given in 6. L shall be taken as distance centre-to-centre of the rafters or other supports of the purlins.
The calculated deflection should not exceed those permitted for the type of cladding used. In calculating the bending moment advantage may be taken of the continuity of the purlin over supports. Side and end sheeting rails shall be designed for wind pressures and vertical loads. The calculated deflections should not exceed those. Fe S or Fe 4 W and slofies not exceeding. The maximum fibre stress shall not exceed the values specified in 6.
The loads shall be assumed as acting normal to the roof in which case the bending about the minor axis may be neglected. Members subjected to axial compression and bending shall be proportioned to satisfy the following requirements: Compression and Bending.
The following meaning: I The value of 2bCX and to be used in the above formulae shall each be lesser of the values of the maximum permissible stresses bbC given in Section 6 for bending about the appropriate axis.
In the absence of such analysis. Irrespective of any increase in the germissible stress specified in 3. For members whose ends are restrained C. As much of the work of fabrication as is reasonably practica le shall be completed in the shops where the steel work is fabricateB. Where a bearing stress is combined with tensile or compressive.
In all other connections sufficient number of one type of fastening shall be provided to communicate the entire load for which the connection is designed. In any connection which takes a force directly communicated to it and which is made with more than one type of fastening. Oe3 In all other cases bolts in clearance holes may be used provided that due allowance is made for any slippage.
Gusset plates shall be designed to resist the shear. Where the packing is too thin to carry the load or permit the provlsion of ade uate welds. Re-entrant cuts shall be avoided as far as practicable. For triangulated frames designed on the assumption of pin jointed connections.
Where a packing is used between two parts. Where properly fitted packings are subjected to direct compression only. Number of rivets or bolts carrying calculated shear through a packing shall be increased above the number required by normal calculations by 2.
For double shear connections packed on both sides. Wherever practicable. The additional rivets or bolts should preferably be placed in an extension of the packing. Bolts and separators may be used provided that in beams having a depth of mm or more. Where two or more rolled steel joists or channels are used side by side to form a girder. In calculating shear and bearing stresses the effective diameter of a rivet shall be taken as the hole diameter and In calculating the axial tensile that of a bolt as its nominal diameter.
When loads are required to be carried from one beam to the other or are required to be distributed between the beams. TABLE 8. The diameter of a rivet hole shall be taken as the nominal diameter of a rivet plus 1. ISr 8. The diameter of a bolt hole shall be taken as the nominal diameter of the bolt plus I. Bolts and Welds 8. The distance between centres of rivets should be not less than 2.
Permissible IS: In the case of compression members in which farces are transferred through butting faces. WY OSl. The provisions contained in 8. Rivets and bolts subject to both shear and axial tension shall be so proportioned that the shear and axial stresses calculated in accordance with 8. Where two or more parts are connected together.
In the case of work not exposed to weather. In both cases. In cases of members covered under I. For rivets in tension with countersunk heads. No reduction need be made in shear.
The requirements bolts shall be the same as for rivets given in 8. Where the loads exceed 6 times the diameter of the by normal calculation shall be increased each additional 1. For countersunk heads.
Washers with perfectly flat faces should be provided Steel or malleable with all close tolerance bolts and turned barrel bolts.
Edge Distances for Tacking Bolts. Wherever there is risk of the nuts becoming loose due to vibration or reversal of stresses. For requirements of welds and welding. The those given in IS: The nominal diameter of the barrel shall be in multiples of 2 mm and shall be at least 2 mm larger in diameter than the screwed portion.
Tolerance dimepsions Close of black tolerance bolts bolts shall shall conform. Structures or portions of structures proportioned using plastic design shah have sufficient strength as determined by plastic analysis to support the working loads multiplied by load factors as given below: Working Loads Load Factor.
Reference may also be made to SP 6 GeneraY 9. X Load Factors. Deflections under working loads shall be in accordance with relevant provisions of this code. Beams 9. IS I - medium weight beams 9.
Such a member shall be designed according to the maximum permissible stress requirements satisfying: If an accurate estimate of the elastic buckling load is The elastic buckling load of a frame or its components designed on the basis of plastic theory shall be at least three times the plastic collapse load. Where Tl is the thickness of flange of a section sion or the aggregate thickness of plates if connected Section 8.
The distance between adjacent parallel lines of attachment of a compression flange or another compression element to other parts of member. For the purpose of this clause. When the web is subjected to bending and compression. A flange or other compression required to participate in a plastic hinge shall not project beyond most point of attachment by more than Y moment v. In this clause M. With the approval of the appropriate authority the design engineer may use the methods which allow a reduced amount of bracing to be used..
This may be too great for some design circumstances. The area of such stiffeners. Web shall be provided when the requirements of case the stiffeners or doubler plates shall portion of the force which exceeds the shear stiffeners or doubler plates 9. This requirement shall be deemed to be satisfied if web stiffeners are placed: Web stiffeners shall be provided at points on a member where the concentrated force delivered by the flanges of another member framing into it will produce web crippling opposite the compression flange or high tensile stress in the connection of the tension flange.
The lateral restraints provided by this clause will ensure that a section delivers its full moment and deformation capacity. It shall be permissible to fit the stiffeners against the inside face of the flange adjacent to the concentrated compression force without welding.
When the concentrated force is delivered by only one beam connected to an outside face 0f. Web stiffeners shall be provided at all plastic hinges where the applied load exceeds 0. A member may be designed as an encased column when the following conditions are fulfilled: The provisions of Section 11 with respect to workmanship shall govern the fabrication of structures. The calculated load capacities of welds. The overall dimensions of the steel section do not exceed x mm over plating where used, the larger dimension being measured parallel to the web; The column is unpainted and is solidly encased in ordinary dense concrete, with 20 mm aggregate unless solidity can be obtained with a larger aggregate and of grade designation M 15, Min see IS: The casing is effectively reinforced with steel wires.
The wire shall be at least 5 mm in diameter and the reinforcement shall be in the form of stirrups or binding at not more than mm pitch so arranged as to pass through the centre of the c: At the column base provision shall be made to transfer the load to the footing at safe unit stresses in accordance with IS: The radius of gyration about its other axis shall be taken as that of the uncased section.
NOTE This clause does not apply to steel struts of overall sectional dimen-. The beam is unpainted and is solidly encased in ordinary ldense concrete, with 10 mm aggregate unless solidity can be obtained with a larger aggregate , and of a grade designation M 15, Min see IS: This allowance should be made by assuming for the purpose of determining the permissi; ble stress in compression that the equivalent moment of inertia Ir about the y-y axis is equal to A.
Other properties required for referring to 6. The permissible bending stress so determined shall not exceed l-5 times that permitted for the uncased section. NOTE - This clause does not apply to beams and girders having a depth greater than 1 mm, or a width greater than mm or to box sections.
Tolerances for erection of steel structures shall conform to the Indian Standard. The erection clearance at ends of beams without web cleats should be not more than 3 mm at each end, but where, for practical reasons, greater clearance is necessary, suitably designed seatings should be provided.
Gas cutting by mechanically controlled torch may be permitted for mild steel only. Gas cutting of high tensile steel may also be permitted provided special care is' taken to leave sufficient metal to be removed by machining so that all metal that has been hardened by flame is removed.
Hand flame cutting may be permitted subject to the approval of the inspector. For dynamically loaded structures. The component parts shall be assembled and aligned in such a manner that they are neither twisted nor otherwise damaged.
The thickness of material punched shall be not greater than 16 mm. Finished holes shall be not more than 1. All holes not drilled through all thicknesses at one operation shall be drilled to a smaller size and reamed out after assembly.
Where this is not practicable. They shall. For multiple riveted connections. Caps a-d Bases In column caps and bases. If so specified. Slab bases and slab caps.
A bearing face which is to be grouted direct to a foundation need not be machined if such face is true and parallel to the upper face. The parts shall be shop assembled with sufficient numbers of parallel drifts to bring and keep the parts in place. ISt All projecting plates or bars and all ends of members at joints shall be stiffened. This does not apply to the interior of sealed hollow sections.
No structure or part of the structure. All structural steel should be so stored and handled at the site that the members are not subjected to excessive stresses and damage. The inspector. The positioning and levelling of all steelwork.
The suitability and capacity of all plant and equipment used for erection shall be to the satisfaction of the engineer. Where specified.
All rivet and bolt heads and the site welds after de-slagging shall be cleaned. Bolts which have been galvanized or similarly treated are exempted from this requirement. Rivets driven at the site shall be heated and driven with the same care as those driven in the shop.
Damaged or deteriorated paint surfaces shall first be made good with the same type of paint as the shop coat. Field bolting same care as required for shop bolting. All field assembly and welding shall be executed in accordance with the requirements for shop fabrication exceptWhere the steel has ing such as manifestly apply to shop conditions only. Bred upon Survey of India map with. Responsibility for the correctness of internal details rests with the publishers. Q Government of India Copyright In Fig.
In the later case. C-l and Fig. C-l when relative displacement of the ends of the column is prevented and in Fig. C-2 when relative lateral displacement of the ends is not prevented. In the absence of more exact analysis.
The provisions of D-l. AND xl. AND El. BOR i. Coefficient kl for effective length of bottom part of double stepped column shall be taken from the formula:. Cluusc D AND k. C Wectively held in position and restrained against rotation bottom end.
Effectively held in position and rertrained against rotation at both ends. Safe load tables for laterally Steel Construction. J Inst. New York. Buckling Hill. Engrs Aust. Aug Background Committee of Japan. V CE Institution of Engineers. Guide to design criteria for metal compression members. John Wiley. Elastic stability of propped cantilevers. Elastic Stability of I-beam element in rigid-jointed frames. Strength of Metal Theory of elastic stability. Stability of structure under static and dynamic loads.
American Society of Civil Engineers. Australian Institute of of beams. June Column Research Council. April McGraw- Structures.
New Jersey Structural members and frames. Column Research 1. Collaboration of building designer and steelwork designer shouId begin at the outset of the project by joint consideration of the planning and of such questions as the stanchion spacing. ISrfmJg4 g Limiti of length and weight of steel members in transit and erection; h Drawings of the substructure, proposed or existing, showing: In the case of new work, the substructure should be designed.
Reference to bye-laws and regulations affecting the steelwork design and construction. Plans of the floors and roof with principal dimensions, elevations and cross sections showing heights between floor levels. The occupancy of the floors and the positions of any special loads should be given. So if you want to download IS: Share this: Twitter Facebook. Like this: Like Loading Leave a Reply Cancel reply Enter your comment here Fill in your details below or click an icon to log in: Email required Address never made public.
IS The standard was revised in and subsequently in , incorporating certain very important changes. IS is the basic Code for general construction in steel structures and is the prime document for any structural design and has the influence on many other codes governing the design of other special steel structures, such as towers, bridges, silos, chimneys, etc.
Realizing the necessity to update the standard to the state of the art of the steel construction technology and economy, the current revision of the standard was undertaken. The revised standard will enhance the confidence of designers, engineers, contractors, technical institutions, professional bodies, and the industry and will open a new era in safe and economic construction in steel.
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