RAJEEV SHAH & ASSOCIATES
STRUCTURAL CONSULTANTS
STRUCTURAL DESIGN BASIS REPORT
HOUSE FOR GOLCHHA FAMILY
KATHMANDU,NEPAL
RAJEEV SHAH & ASSOCIATES
FLAT NO :- 15, 4TH FLOOR ,RADHA APARTMENT, R.S.M MARG, TELLI
GULLY,ANDHERI ( E ) MUMBAI :- 400069
CONTACT:- 022-2 6 8 4 4 8 4 1 / 6 5 2 2 9 6 0 1
FAX: 2 6 8 3 3 0 6 3
Email :- rbaps@rediffmail.com / bapashah@gmail.com
1
CONTENTS
1. Structural Design Introduction
2. Project Features
3. Foundation
4. List of References
5. Material, Workmanship, Inspection and Testing
6. General Design Consideration
7. Conclusion
1) Structural Design Introduction:
The proposed structure is a residential bungalow for Golccha family in
Kathmandu,Nepal. The structure is a G+1+Terrace structure in RCC.
In this brief report we are presenting the data and assumptions related to the
project, which has lead to the conceptual design at this preliminary stage.
The document attempts to record all inputs assumed in design and will form the
basis for all future detailed structural work.
The report most importantly clarifies the load criteria assumed in the design and
it is therefore expected that all related consultants, including the architects, would
go through the document and refer to it at every stage of detailed design.
Recommendations or revisions on assumed parameters are requested at this
stage.
Besides this the report will also form the outline of the design criteria and
methods of both analysis and design to be adopted in this project with the aim of
achieving a design that satisfies all sorts of seismic, and serviceability
requirements.
2) Project Features:
The proposed project is a Bungalow Project in RCC. The proposed building is a
Ground+1+Terrace RCC Residential structure.
3) Foundation system:
Geotechnical Investigation for the site has been carried out by “M/s.
MULTI LAB (P) LTD ,NEPAL” and the foundation system is decided
based on this report.
1) Upto 3M depth is Filling materials including yellow to gray clayey silt
with pieces of brick, concrete & gravels.
2) From 3-4.7M is Yellow to brown clayey silt of low plasticity with gravels.
3) From 4-7.7M Dark gray clayey silt of low plasticity.
4) From 7.7-12M Dark gray clayey silt of low plasticity with traces of
gravels.
5) Isolated foundation is suggested at 2m depth.
6) We considered SBC of 10Ton/M2 at 2.5m depth and designed the strip
foundation connected with Raft.
4) List of References:
IS 456-2000 Plain and reinforced concrete-code of practice
IS 800-2007 General Construction is Steel
IS 875 Code Of practice for design loads for buildings and
structures
Part 1: 1987 dead loads- unit weights of building material and stored
material
Part 2: 1987 Imposed loads
Part 3: 2015 Wind loads
SP34 Handbook of Concrete Reinforcement and Detailing
Reynolds handbook
5) Material, Workmanship, Inspection and Testing:
The proposed RCC structure will consists of concrete, untensioned
reinforcement and structural steel as the three main materials used for
construction of the structure. The specifications for these materials are
discussed in this chapter.
5.1 Concrete:
The concrete shall be in grades designated as per Table 2 IS 456-2000.
Recommended grades for the different members is as follows:
Foundation M35
Columns M25
Beams/Slabs M35
Water Tanks M35
Any other structural member will be in general designed in M35.
5.2 Reinforcement:
The reinforcement shall be high strength deformed steel bars of grade
Fe-500D to be used for entire structure.
5.3 Durability of concrete
The structure is in Kathmandu,Nepal where the climatic conditions are
considered moderate. Concrete grade of submerged structures will be a
minimum of M25. Nominal covers shall not be less than 20mm from a
durability point of view.
The cover to the various structural elements is to be as follows,
Structural Element Clear Cover in mm
Slabs 25
Beams 30
Columns 45
Pile Cap /Foundation 75
Retaining wall 45
Pile & Other Structural 45
elements under ground
5.4 Structural Steel
The structural steel to be used shall confirm to IS 800.
5.5 Construction Joint
Construction joints and shrinkage strips will be planned with the contractor
and only be used in locations pre-approved by consultants.
6) General design considerations:
6.1 Method of Design
The aim of design is the achievement of an acceptable probability that
structures being designed will perform satisfactorily during their intended life.
With an appropriate degree of safety, they should sustain all the loads and
deformations of normal construction and use and have adequate durability
and adequate resistance to the effects of misuse and fire.
Structures and structural elements will be designed by Limit State Method.
Due consideration will given to the accepted theories, experience and modern
philosophy of design.
6.2Loads and Forces
In structural design, account is taken of the dead, imposed and wind
loads.
Dead Loads
The dead loads are calculated on the basis of unit weights of materials
given in IS 875 (Part 1). The data provided by MEP consultant and other
service consultants will be used for the specific materials/equipments.
Unless otherwise specified the unit weight of materials will be used as
follows.
Reinforced Concrete 25 kN/cum
Plain concrete 24 kN/cum
Brickwork 20 kN/cum
Concrete block work 24 kN/cum
Siporex Blocks 8.0 kN/cum
Stone cladding 25 kN/cum
Soil dry 15 kN/cum
Soil wet 18 kN/cum
Floor finishes 20 kN/cum
Sandwich Puff Panel 0.4KN/Cum
Imposed Loads
Imposed loads are assumed in accordance with IS 875 part 2, as follows.
The table listed below is a summary of these loads.
Loads For school bldg.
1 Ground Level kN/sqm Comments
Plinth Beam 20.7KN/M Assuming 4.5M average height of brickwork.
Assuming load to be transferred on to the filling
Grade Slab 0 and no load transfer to plinth beam
2 Roof Level
Purlins spacing at 1M 60Kg/M2 Live load
1.6Kg/M2 Considering 40Kg/m3 and thickness as 40MM
Purlins are working at this load.(Staad model
Purlins just to checked at 150Kg/m2 attached at 150kg/m2)
Load Combinations considered:
1. D.L + L.L
2. D.L + 0.8(L.L + Wxz + )
3. D.L + 0.8Wxz +
4. 1.5(D.L + L.L)
5. 1.2(D.L + L.L + Wxz + )
6. 1.5(D.L + Wxz + )
7. 0.9D.L +1.5 Wxz +
6.3 Analysis Approach
Structural Geometry:
The structure consists of 1 Sloping roof varying in height from 3.3M to
7.9M.
7 Conclusions.
7.1 Other loads: Any other loads like those of services; storage etc will be
obtained from time to time from the relevant consultants and incorporated.
7.2 Column locations: The location of the columns has been retained as per
conceptual drawings received. Although additional columns are added wherever
required.
This DBR attempts to briefly cover all design related methods and assumptions
at this stage of the project. As the project progresses certain revisions to the
DBR might be warranted and such timely revisions of this report will be promptly
provided by us.
