Civil Engineering/RC buildings


I am a neophyte engineer trying to get to grips with structural design and hence thought of sending you my query. In order to design an RC building say, 50-80m in length, does one need to incorporate expansion joints? Secondly, in East Africa, I believe, majority of residential buildings are on pad foundations, obviously, dependent on ground bearing capacity. However, for a building that is say 8 stories in height, is it possible to use pad foundations on limestone strata?
Kind regards

Hi Keesh,

A rule of thumb is to have a joint every 50m approximately, but if the joint causes other problems then you can design for additional thermal stresses and do even 100m without joints.

Yes, so long as the applied pressure under the pads is within the bearing capacity and without causing excessive long-term settlement, there is no reason why pad footings cannot be used.

Civil Engineering

All Answers

Answers by Expert:

Ask Experts


Arshad Khan


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.


Employment history: 40 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.

.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)

•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 •2013: IEK International Conference, Kisumu, Kenya

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 2010)

©2017 All rights reserved.