Is1893 part 1 2006 code pdf download

The use of foundations vulnerable to significant differential settlement due to ground shaking shall be avoided for structures in seismic Zones III, IV and V In seismic Zones IV and V, individual spread footings or pile caps shall be interconnected with ties, except when individual spread footings are directly supported on rock.

Empirical expression for estimating the fundamental natural period Ta of multi-storeyed buildings with regular moment resisting frames has been revised.

This excludes the basement storeys, where basement walls are connected with the ground floor deck or fitted between the building columns. But it includes the basement storeys, when they are not so connected. The concept of response reduction due to ductile deformation or frictional energy dissipation in the cracks is brought into the code explicitly, by introducing the response reduction factor in place of the earlier performance factor.

No 1 2 3 1 Moment resistant frame with appropriate ductility in reinforced concrete or steel Frame as above with R. Steel moment resisting frame designed as per SP 6 Load bearing masonry wall buildings a Unreinforced b Reinforced with horizontal RC bands c Reinforced with horizontal RC bands and vertical bars at corners of rooms and jambs of openings.

The code now requires that there be a minimum design force based on empirical fundamental period Ta of the building even if the dynamic analysis gives a very high value of natural period and thus low seismic force. Torsional eccentricity values have been revised upwards in view of serious damages observed in buildings with irregular plans.

As per IS Provision shall be made for the increase in shear resulting from the horizontal torsion due to an eccentricity between the centre of mass and the centre of rigidity. The design eccentricity shall be taken as 1.

Negative torsional shears shall be neglected. Modal combination rule in dynamic analysis of buildings has been revised. Modal analysis using Greater than 40 m and All zones Irregular buildings All framed response spectrum up to 90 m method.

Less than 40 m All zones Modal analysis using response spectrum method. Use of seismic coefficient method permitted in all zones. Editorial and Typographical Errors Direction of horizontal ground motion in design Clause 6. Fundamental natural period Clause 7. In this Clause brick infill panels should be replaced by masonry infill panels Clause 7. All framed buildings higher than 12m. Modal combination Clause 7. The equation should be as follows:. Seismic zone map In first printing of the code, some errors got introduced in the seismic zone map.

The Indian Concrete Journal November Open navigation menu. Close suggestions Search Search. User Settings. Skip carousel. Also, this standard Part 1 deals with earthquake-resistant design of buildings; earthquake-resistant design of the other structures is dealt with in Parts 2 to 5.

For such structures, additional requirements may be imposed based on special studies, such as site-specific hazard assessment. In such cases, the earthquake effects specified by this standard shall be taken as at least the minimum. At the time of publication, the editions indicated were valid.

All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below: IS No. Title Code of practice for plain and reinforced concrete fourth revision IS No. In this condition, the soil tends to behave like a fluid mass see Annex F. Since the amplitudes of mode shapes can be scaled arbitrarily, the value of this factor depends on the scaling used for defining mode shapes.

A structure with N degrees of freedom possesses N natural periods and N associated natural mode shapes. This mode of oscillation is called the fundamental lateral translational natural mode of oscillation. A three- dimensional model of a structure will have one such fundamental lateral translational mode of oscillation along each of the two orthogonal plan directions.

Here, the acceleration refers to that of the horizontal motion, unless specified otherwise. It depends on the perceived seismic damage performance of the structure, characterized by ductile or brittle deformations, redundancy in the structure, or overstrength inherent in the design process.

The response referred to here can be maximum absolute acceleration, maximum relative velocity, or maximum relative displacement. For buildings with basements, it is considered at the bottommost basement level. For buildings resting on, a pile foundations, it is considered to be at the top of pile cap; b raft, it is considered to be at the top of raft; and c footings, it is considered to be at the top of the footing.

For buildings with combined types of foundation, the base is considered as the bottom-most level of the bases of the constituent individual foundations as per definitions above. Unless otherwise stated, the inertia force considered is that associated with the horizontal shaking of the building. In step-back buildings, it shall be taken as the average of heights of all steps from the base, weighted with their corresponding floor areas.

And, in buildings founded on hill slopes, it shall be taken as the height of the roof from the top of the highest footing level or pile cap level. This, a excludes the basement storeys, where basement walls are connected with the ground floor deck or fitted between the building columns; and b includes the basement storeys, when they are not so connected. A structure with this structural system has enhanced lateral stiffness, wherein core structural walls and perimeter columns are mobilized to act with each other through the outriggers, and the perimeter columns themselves through the belt truss.

The global lateral stiffness is sensitive to: flexural stiffness of the core element, the flexural stiffness of the outrigger element s , the axial stiffness of the outrigged column s , and the flexural stiffness of the outrigger elements connecting the core structural walls to the perimeter columns.

The storey lateral stiffness is the total stiffness of all seismic force resisting elements resisting lateral earthquake shaking effects in the considered direction. The storey lateral strength is the total strength of all seismic force resisting elements sharing the lateral storey shear in the considered direction. The random earthquake ground motions, which cause the structure to oscillate, can be resolved in any three mutually perpendicular directions.

The predominant direction of ground vibration is usually horizontal. Effects of earthquake-induced vertical shaking can be significant for overall stability analysis of structures, especially in structures a with large spans, and b those in which stability is a criterion for design.

Reduction in gravity force due to vertical ground motions can be detrimental particularly in prestressed horizontal members, cantilevered members and gravity structures. Hence, special attention shall be paid to effects of vertical ground motion on prestressed or cantilevered beams, girders and slabs.

This standard specifies design forces for structures founded on rocks or soils, which do not settle, liquefy or slide due to loss of strength during earthquake ground vibrations. Ductility arising from inelastic material behaviour with appropriate design and detailing, and overstrength resulting from the additional reserve strength in structures over and above the design strength are relied upon for the deficit in actual and design lateral loads.

In other words, earthquake resistant design as per this standard relies on inelastic behaviour of structures. But, the maximum ductility that can be realized in structures is limited.

Therefore, structures shall be designed for at least the minimum design lateral force specified in this standard. Some provisions for appropriate ductile detailing of RC members are given in IS Members and their connections of steel structures should be so proportioned that high ductility is obtained in the structure, avoiding premature failure due to elastic or inelastic buckling of any type.

Some Soil-structure interaction may not be considered in the seismic analysis of structures supported on rock or rock-like material at shallow depth. In such cases, it may be necessary to obtain floor response spectra for design of equipment and its supports. For details, reference may be made to IS Part 4.

Therefore, usually, resonance of the type as visualized under steady-state sinusoidal excitations will not occur, as it would need time to build up such amplitudes. But, there are exceptions where resonance-like conditions have been seen to occur between long distance waves and tall structures founded on deep soft soils.

In addition, those specified in this standard shall be applicable, which include earthquake effects. Thus, EL in the load combinations given in 6. Hence, the sets of load combinations to be considered shall be as given below: 1 1. This implies that the sets of load combinations involving earthquake effects to be considered shall be as given below: 1 1.

For determining the type of soil for this purpose, soils shall be classified in four types as given in Table 2. In soft soils, no increase shall be applied in bearing pressure, because settlements cannot be restricted by increasing bearing pressure. Such sites should be avoided preferably for locating new structures, and should be avoided for locating structures of important projects. Otherwise, settlements need to be investigated, and appropriate methods adopted of compaction or stabilization to achieve N values indicated in Note 4 of Table 1.

Audio Software icon An illustration of a 3. Software Images icon An illustration of two photographs. Images Donate icon An illustration of a heart shape Donate Ellipses icon An illustration of text ellipses. EMBED for wordpress. Want more? For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall be -rounded off in accordance with IS 2: Rules for rounding off numerical values revised.

The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard. This standard describes the procedures for earthquake resistant design of industrial structures. It provides the estimates of earthquake loading for design of such structures. In addition to the above, the following structures are classified.

At the time of publication the editions indicated were valid. Automobile industries;Title