Civil Engineering/etaabs

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Expert: - 10/1/2009


Question
QUESTION: Dear Sir,

While doing analysis in etaabs ,Is it better to consider analysis property modification factors for all   to be '1' or which value is preferable ? thanking you..

ANSWER: Hi Raviarjun,

This depends what you are analysing for- in simple terms, if it is for wind loading, you can use 1, but for seismic loading you need to use the modifiers as per applicable codes- such as UBC or ACI 318. The factors range from 0.25 to 0.7, depending on whether they are slabs or beams or walls.

For long-term deflections, use the modifiers, for short term deflections/sway assessments use 1.0

---------- FOLLOW-UP ----------

QUESTION: Dear Sir,
thanx so much .could I get an idea of the preferable ratio for beam,slabs and walls seperately..
thanking you..

Answer
Hi Raviarjun,

Visit this website and scroll up to section 10.11.1 and you will see all the factors.

http://books.google.com/books?id=oa8XnnvX6BgC&pg=PA133&lpg=PA133&dq=aci+318+sect

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Arshad Khan

Expertise

I can answer any questions to do with civil and structural engineering consultancy and construction industry in East Africa and the Middle East, and specifically with the analysis and design of reinforced concrete structures. My particular expertise is in the aseismic design and optimisation of tall buildings.

Experience

Employment history: 36 years in Construction and consultancy in the UK, Kenya, Tanzania, Uganda, Ethiopia, Eritrea, South Africa, Somalia, Zambia, Austria, Bahrain, Kuwait, Doha and the U.A.E.

Organizations
.Fellow of Institution of Structural Engineers (UK) .Fellow of Institution of Civil Engineers(UK) .Member of the Institution of Engineers, Kenya .Registered Engineer, ERB, Kenya .Member of the Architectural Association of Kenya (Engineers Chapter) .Chartered Engineer (UK)

Publications
•1984: International Conference on the Art and Practice of Structural Design, London •1994: 3rd Int. Kerensky Conference in Structural Engineering, Singapore •2008: International Conference on High-Rise Towers, Abu Dhabi

Education/Credentials
BSc, 1st Class Hons, in Building Engineering, University of Bath, UK MSc in Concrete Structures and Technology, University of London. Diploma of Imperial College, UK.

Awards and Honors
•Science Congress Special Award (for 2-seater Hovercraft - 1968) •Institution of Civil Engineers Award for outstanding performance at Bath University (1975) •Concrete Society Postgraduate study Bursary Award (1976) •Consular Representative for British High Commission, Nairobi. (1995 to 1998) •Examiner for Institution of Civil Engineers Professional Interviews, Nairobi. (1997 to 1998) •Branch Representative in Vienna for PI assessment for Inst. of Struct. Engrs. (1999 to date)

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