Notwithstanding anything contained in these rules a building shall comply with special requirements, if any, laid down in Factories Act, 1948 (63 of 1948) or in any other law for the time being in force in relation to such building.
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PART VIII Structural Design
81. Structural design -
(1) Structural design and safety For any building under the jurisdiction of these regulations structural design/ retrofitting shall only be carried out by an empanelled Structural Engineer. Proofchecking ofvarious designs/reports shall be carried out by competent authority as per Table at clause (e) below wherever applicable.
(a) Additionalprovisions in building regulations/bye—lawsfor natural hazardprone areas Generally, the structural design of foundations, elements of masonry, timber, plain concrete, reinforced concrete, pre-stressed concrete and structural steel shall confirm to the provisions ofPart 6: Structural Design - Section 7 I Loads, Forces and Effects Section 7 2 Soils and Foundations, Section 7 3 Timber and Bamboos, Section 7 4 Masonry, Section 7 5 Concrete & Section 7 6 Steel Section 7 7 prefabrication System, building and Mixed/ Composite Construction of National Building Code ofIndia (NBC), taking into consideration the Indian Standards as amended upto date as given below:
For General Structural Safety I) IS: 456:2000 “Code ofPracticefor Plain and Reinforced Concrete. ” 2) IS: 800-2007 “Code ofPracticefor General Construction in Steel. ” 3) IS: 801-1975 “Code ofPracticefor Use ofCold Formal Light Gauge Steel Structural Members in General Building Construction. ” 4) IS 875 (Part 2): I987 Design loads (other than earthquake)for buildings and structures Part 2 Imposed Loads.
fleeference ofTable 4.1- ”Occupant Load ” may be consideredfor design load) 5) IS 875 (Part 3): I987 Design loads (other than earthquake)for buildings and structures Part 3 Wind Loads.
6) IS 875 (Part 4): I987 Design loads (other than earthquake)for buildings and structures Part 4 Snow Loads.
7) IS 875 (Part 5): I987 Design loads (other than earthquake)for buildings and structures Part 5 special loads and load combination.
8) IS: 883:I994 “Code ofPracticefor Design ofStructural Timber in Building. ” 9) IS: 1904:1986 (R 2005) “Code ofPracticefor Design ofStructural Safety of Buildings: Foundation ” Page 52 10) IS: 1905:1987 (R 2005) “Code ofPracticefor Design ofStructural Safety of Buildings: Masonry Walls ” 11) IS 2911 (Part 1): Section 1: 2010 “Code ofPracticefor design and Construction ofPile Foundation Section 1 Part 1: Section 2 Bored Cast-in-situ Piles Part 1: Section 3 Driven Precast Concrete Piles Part 1: Section 4 Bored Precast Concrete Piles Part 2: Timber Piles Part 3: Under Reamed Piles Part 4: Load Test on Piles For Cyclone/Wind Storm Protection 12) IS 875 (3): 1987 “Code ofPracticefor Design Loads (other than Earthquake) for Buildings and Structures, Part 3, Wind Loads ” 13) Guidelines (Based on IS 8 75 (3)-1987) for improving the Cyclonic Resistance ofLow rise houses and other building.
For Earthquake Protection 14) IS: 1893 (Part I)- 2002 "Criteriafor Earthquake Resistant Design ofStructures (Fifth Revision) ” 15) IS: 13920-1993 “ Ductile Detailing ofReinforced Concrete Structures subjected to Seismic Forces 7 Code ofPractice” 16) IS: 4326-2013 “Earthquake Resistant Design and Construction ofBuildings 7 Code ofPractice (Second Revision) ” 1 7) IS: 13828-1993 “Improving Earthquake Resistance ofLow Strength Masonry Buildings 7 Guidelines ” 18) IS: 1 382 7-1993 “Improving Earthquake Resistance ofEarthen Buildingsi Guidelines ” 19) IS: 13935-2009 ”Seismic Evaluation, Repair and Seismic Strengthening of Buildings 7 Guidelines ” For Protection ofLandslide Hazard 20) IS 14458 (Part 1): 1998 Guidelinesfor retaining wallfor hill area: Part 1 Selection of type ofwall.
21) IS 14458 (Part 2): 1997 Guidelinesfor retaining wallfor hill area: Part 2 Design ofretaining/breast walls.
22) IS 14458 (Part 3): 1998 Guidelinesfor retaining wallfor hill area: Part 3 Construction ofdry stone walls.
23) IS 14496 (Part 2): 1998 Guidelinesforpreparation oflandslid -- Hazard zonation maps in mountainous terrains: Part 2 Macro-Zonation.
Note: Whenever an Indian Standard including those referred in the National Page 53 (’1) Building Code or the National Building Code is referred, the latest revision ofthe same shall befollowed except specific criteria ifany, mentioned above against that code.
Structural Design Basis Report (SDBR) In compliance of the design with the above Indian Standard, the empanelled Structural Engineer will submit a structural design basis report in the Proforma attached herewith covering the essential safety requirements specified in the standard.
((0 The “Structural Design Basis Report (SDBR) ” consists offourparts - Part 1: General Information /Data Part 2: Load bearing Masonry Buildings Part 3: Reinforced Concrete Buildings Part 4: Steel Buildings 1) Drawings and Documents to be submitted for approval of appropriate authorities shall include SDBR as detailed bow:
Part 1: Completed Part 2: (ifapplicable) , completed Part 3: (if applicable) , undertaking that completed Part 3 will be submitted before commencement ofconstruction.
Part 4: (if applicable) - undertaking that completed Part 4 will be submitted before commencement ofconstruction.
ii) SDBR as detailed below shall be submitted to the appropriate authority as soon as design offoundation is completed, but not later than one month prior to commencement of construction.
Part 1: Completed Part 2: Part 3: Part 4 (ifapplicable) Completed Seismic strengthening /retrofitting Prior to seismic strengthening /retrofitting of any existing structure, evaluation of the existing structure as regards structural vulnerability in the specified wind/seismic hazard zone shall be carried out. Ifas per the evaluation the seismic resistance is assessed to be less than the specified minimum seismic resistance as given in the note below, action will be initiated to carry out the upgrading of the seismic resistance of the building as per applicable standard guidelines.
Note:
1. For masonry building reference shall be made to IS 4326 and IS 13935
2. For concrete buildings and structures reference shall be made to IS 15988: 2013 Seismic evaluation and strengthening ofexisting RCC buildings.
Building with Soft Storey In case ofbuildings with a flexible storeys, such as the ground storey consisting ofopen spaces for parking that is “Still building” or any other storey with open halls, special arrangements are to be made to increase the lateral strength and stifi’ness of the soft/open storey such as Steel bracing/ Shear walls /Brick infills between columns.
Dynamic analysis of building is to be carried out including the strength and stiffness eflects of infills and inelastic deformations in the members, particularly; those in the soft storey and the structural members are to be designed accordingly. Alternatively, the following design criteria Page 54 are to be adopted afier carrying out the earthquake analysis, neglecting the effect of infill walls in other storeys:
a. The column and beams of the soft storey shall be designedfor 2.5 times the storey shears and moments, calculated under seismic loads specified in the other relevant clauses: or b. Besides the columns designed and detailedfor the calculated storey shears and moments, shears walls shall be placed symmetrically in both directions of the building as far away from the centre of the building as feasible; to be designed exclusively for 1.5 times the lateral storey shear force calculated as before. For details of design and provisions, IS 1893, Part I shall be referred.
(e) Review ofstructural design 1) The Competent Authority shall review and suggest addendum to the certificate or a new certificate in case ofsubsequent changes in structural design.
iii) Table below gives requirements of empanelled Structural Engineer for different seismic zones namely III, IVand Vandfor structures ofdifferent complexities.
iv) In seismic Zone II, buildings & structures greater than 40m in height will require proof checking as per details at Sl. No. 3 ofTable below.
ProofChecking Requirementsfor Structural Design Sl. No. Type ofStructure Submission from To be Proof empanelled Structural Checked Engineer I Load Bearing Buildings SDBR* Not to be upto three storeys checked 2 Building upto seven storeys SDBR To be checked m. C. C/Steel framed Preliminary design To be checked structure) 3 Building greater than SDBR To be checked seven storey (R. C. C/Steel Preliminary design To be checked flamed structure) Detailed structural design To be checked and structural drawings 4 Special Structures SDBR To be checked Preliminary design To be checked Detailed structural design To be checked and structural drawings * SDBR 7 Structural Design Basis Report Notes:
I. Table 4.1 may be referredfor Occupant Load Live loadfor different building types.
2. At the preliminary proposal stage ofa project, the objective is to undertake feasibility study comparison of a number ofpossible alternatives ofstructural schemes and determine the most cost effective one, detailed structural calculations are not necessary for each alternative scheme. However, it is conservative assumption it is possible to derive simplified calculations for analysis and design. This is called ”Preliminary or appropriate analysis, and design ” After the most cost effective scheme is selected and signed-ofl by the Client, the detailed calculations are performed on the selected scheme to determine the precise structural members and composition (size, dimension and stress behavior), and this is called the “Detailed structural design”.
Page 55 In the aforesaid , the design of structural members is typically assumed to account for all the stress loads identifiedfrom section xx to be applicable in the given project
3. Special structure means large span structures as stadium, assembly halls, or tall structures such as water tanks. TV tower, chimney, etc.
0‘) Certification regarding structural safety in design Empanelled Structural Engineer shall give a certificate ofstructural safety ofdesign as per standardproforma.
(g) Constructional safety
(i) Supervision All construction except load bearing building upto 3 storeys shall be carried out under supervision under empanelled Construction Engineerfor various seismic zones.
(ii) Certification ofstructural safety in construction Empanelled Construction Engineer shall give a certificate of structural safety of construction at the time ofcompletion.
(h) Quality control and inspection All material and workmanship shall be of good quality conforming generally to accepted standards of Public Works Department and Indian standard specification and codes as included in part-V Building Materials and Part— VII Construction practices and safety ofNational Building Code OfIndia.
(1) Inspection All the construction for high-rise buildings higher than seven storeys, public building and special structures shall be carried out under quality inspection program prepared and implemented under the empanelled Quality Auditor in seismic zones.
(ii) Certification ofsafety in quality ofconstruction Empanelled Quality Auditor shall give a certificate of quality control. Quality Inspection Programme to be carried on the site shall be worked out by empanelled Quality Auditor in consultation with the owner, builder.
Note: Section (g) and (h) shall not be applicable government buildings that are designed and constructed under the supervision of in house architect/ engineer.
(I) Control and signage & outdoor display structures, cellphone towers and telephone towers.
Followingprovisions shall applyfor telecommunication infrastructurea) Location: The Telecommunication Infrastructure shall be either placed on the building rooftops or on the ground or open space within the premises subject to other regulations.
b) Type ofStructure 1) Steelfabricated towers or antennae ’s on MS. pole.
ii) Pre-fabricated shelters offiber glass or P. V. C. on the building rooftop/ terracefor equipment.
iii) Masonry Structure/ Shelter on the groundfor equipment.
iv) D. G set with soundproofcover to reduce the noise level.
0) Requirement:
1) Every applicant has to obtain/ procure the necessary permission from the “Standing Advisory Committee on Radio Frequency Allocation ” (SACFA) issued by Ministry ofTelecommunication.
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ii) Every applicant will have to produce the structural safety & stability certificate for the tower as well as the building from the empanelled Structural Engineer which shall be the liability of both owner and empanelled Structural Engineer.
iii) Applicant has to produce/submitplans ofstructure to be erected.
d) Projection: No pager and/ or Telephone tower shall project beyond the existing building line ofthe building on which it is erected in any direction.
Structural requirements oflow income housing Notwithstanding anything contained herein, for the structural safety and services for development of low income housing, the relevant provision of applicable IS: 8888 part I shall be enforced along with Annex C ofpart 3 NBC.
Alternative Materials, Methods ofDesign and Construction and Tests The provision of the Bye-Laws are not intended to prevent the use of any material or method of design or construction not specifically prescribed by the bye-law provided any such alternative has been approved. The building materials approved by B.I.S. or any statutory body will form part of the approved building material and technology as part ofthe Bye-Laws.
The Authority shall promote and encourage use ofPre-fabricatedfactory made building components for medium to large scale projects that have significant impact. The use of ready mix concrete (RMC) shall also be encouragedfor in-situ concrete constructions.
While submitting the plan for Ground Floor /Basementfloor ofthe building, the plan should clearly specify the height of the buildingfor which foundation of the building has been designed and all relevant provisions of the Rules related to that designed height ofthe building should befollowedfrom the beginning i. e. from Ground Floor/ Basementfloor ofthe building.
Quality of materials and workmanship.- All materials and workmanship shall be of good quality conforming generally to the accepted standards of the Public Works Department of the Government of Tripura or Indian Standard Specifications as indicated in part V on Building Materials and part VII on Constructional practices and safety of the latest edition of the National Building code of India.
Alternative materials, method of design and construction.- The ULB may approve any alternative material or method of design or construction if the competent authority of the ULB is satisfied that such alternative is satisfactory and conforms to the provisions of the relevant parts of the National Building Code of India regarding materials, method of design and construction and that materials, methods of design or work are for the purpose intended equivalent to those specified in the code in quality, strength, compatibility, effectiveness, fire and water resistance, durability and safety.
Tests.- Whenever there is insufficient evidence of compliance with the provisions of these rules or there is evident that any claim for alternative materials, or design, the ULB may require tests to be made sufficiently in advance or require performance certificate from a body authorized by a state or central government, as proof of compliance and such tests shall be made at the expenses of the owner and in such manner as the ULB may direct.
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