Cracks, Collapses and a National Building Code; An Interview with a Structural Engineer

Disintegration, cracks, sloping floors and more are all signs of a poor foundation and structure. Yet, their possibility depends on the stability of your foundation and how it has been constructed. One of the major components that affects this is the soil and location. This is when structural engineering is required to plan out your construction the right way. 

This week, LankaPropertyWeb conducted an email interview with Mr Ranjith Wijegunasekera, an Intermediate Rise Structural Engineer. Here he gives you an insight on structural engineering, and what you need to know to construct a solid building. 

What is Structural Engineering? 

Structural engineering is a scientific process based on proven theories, research, experiments and sound experiences. This process, known as structural analysis, predicts effects on these elements and their behaviour due to actions which they are subject to, and transfers loads safely to a support system. Having identified the effects on the elements and their behaviour, section properties are determined based on required strength and stiffness. 

How would you define a Structural Engineer as?

A structural engineer identifies and evaluates actions that affect a structure and determines effective and efficient load paths based on the shape of the structure. Safety and robustness of the structure is preserved by ensuring the loads are safely transferred to a support system like a foundation. 

What is the role of a Structural Engineer in a construction? 

A structural engineer develops structural schemes to support architects designs and advises clients and contractors on structure related problems.

Why is a Structural Engineer required in a construction?

While providing a sound structural design for construction, a structural engineer monitors the standard of construction and follows up with due actions when the situation demands.

How will homeowners be benefited by consulting a Structural Engineer before and after constructing their home?

A structural engineer provides a stable, robust, economical and aesthetically pleasing structural scheme. In post-construction, homeowners may consult structural engineers when they require any alteration or modification to the original design. Homeowners can also get a professional opinion when they feel the structure is undergoing distress.

What are the tasks of a Structural Engineer after receiving a house plan? 

A structural engineer studies the environmental factors of the proposed site and directs investigations in accordance with the house plans. He then liaises with the architect and building service engineers to propose a viable structural scheme.

What are some factors people need to consider when building a house or apartment (in general)? 

The primary considerations are the building and the site itself. In terms of the site, foundation solutions are determined by topography and ground condition. Budgetary constraints are important from a financial sense, and accessibility to utilities from a planning sense. 

What are some alarming signs to be mindful of in a house/apartment after time goes by?

Deterioration is typically made evident by progressing cracks, settlements in foundation and crookedness in structural elements. 

The recent Kandy incident brought up the need for a national building code in Sri Lanka. What are your views on it and what difference would it make? 

A national building code is of paramount importance. These guidelines can bring designers and reviewers on to the same platform and bring standardisation to design of buildings. Alternatively, we could develop a national annexure with country specific data to an existing, recognised code of practice. 

What sort of additional concerns should we be mindful of when building a complex in general as well as in particular in the hill country?

If the proposed site is prone to landslides as per the National Building Research Organization (NBRO) classification, then the proposed construction should be avoided. When a hilly site is subject to loading from construction and other activity, there is a tendency to destabilise the slope. Hence, the stability of the slope should be analysed by a thorough geotechnical investigation with recommendations provided by a geotechnical specialist. The recommendations may comprise methods to improve the stability of the slope, type of foundation and its depth, and methods of handling drainage issues.

Are there any special factors to consider when building a house or apartment in Colombo? 

In addition to occupancy, environmental and geotechnical factors, any other client specific requirements should be made known to the design team. In more urban areas, an additional factor that may require further consideration is the effect on adjacent buildings due to ongoing construction activities.  

Given the nature of Sri Lanka and the number of constructions taking place daily, the role of structural engineering is becoming even more important today. So if you are planning to build a home of your own, make sure to consult a structural engineer yourself!