25 Aug 2013

C & S Software Solutions Sdn Bhd  

Building structure for structural consulting engineer (Intermediate)

Whenever a client has an idea of building a unit or more building in their land, it is a starting of ‘life form’ for building. They will start looking for land surveyor, architect, civil and structural engineer, mechanical and electrical engineer and quantities surveyor. All these parties will have to perform their own necessary duty to accomplish the building works. Civil and structural works will be one of portion on project implementation.
As a fresh engineer, he will think that it just get architecture drawings and do necessary design on structural works. i.e. prepare drawings and calculation. With the help of computer software, the task can be accomplished in short of period. Anyway, it is starting of problem of structural works. Actually design of structure has a number of knowledge that hidden behind. It wills not just what as mention above. It will range from theory to practicality. The implementation of design will depend on project case.
Initially architect will come out some preliminary drawings or sketches on building. These drawings or sketches have to gain acknowledgement from client. As a civil and structural engineer, he has to get initial comments on the structural works such as proposed of columns and beams location. This stage is important because it will control on the over cost of structural works and workability of structural design. As for example, when client want to have a spaces area for showroom i.e. columns free. One of the control elements is floor height. If architect is proposed a low floor height, it will affect the final clear height. This is because structural beam element must has deeper depth to control structural deflection. Structural engineer has to tell architect that minimum depth of beam. The minimum depth of beam structure can be obtained from code of practice on structural design. Such as BS8110 and BS5950 of British Standard. The longer span of structural beam, the more depth required. It may advisable on using of steel structure instead of RC structure.
The location of proposed beams and columns may affect the outlook of building. It may works fine on structural design, but it may not fit architecture design or vise versa. Therefore, it is always has more discussion on design work to get “win win” situation. Proposed of structural elements may affect by Fung Shui philosophy. As for example, people who believe Fung Shui may not want a column expose on the centre of main entrance. It will be more trouble when Fung Shui element comes in after building has been constructed. Normally Fung Shui master will has a number of comments on structural elements. Such as, remove existing column. It looks simple but it is a nightmare for engineer, because structural framework has been configured. Removing a column in structural framework will be a major work for engineer. It may includes enhancement of related foundation, introduce transfer beam at position of omitting column. It is a tedious analysis and design. Sometime, the existing condition will cause restraint on new structure adding.
For example on design of apartment structure, architect may allow of columns from top floor to lower floor. Sometime, with introduction of car park a ground floor; certain location of columns has to remove at ground floor; especially location along of driveway. Engineer may happy with columns at upper floor. How to deal with such case when column to be omitted at ground floor? A transfer beam may require. Is the ground floor height is sufficient to gather on transfer beam depth? Is it required to introduce prestress beam for that particular transfer beam?
For design of shopping complex, it will have a number of amendments. Engineer has to base on his own working experience, he has to judge on certain work that may changed or added during or after the construction work. As for example, inexperience architect may lack on allocation of fire fighting tanks. For experience engineer, he has to highlight this to architect for the needs. If the information is unavailable during the planning stage, engineer has to base on his best judgment and estimate the tank volume and location. He has to destine the location of tank for foundation works. During construction, certain location may change on the usage such as shopping lot change to cinema. How to deal with such case? Engineer must aware that the change of usage of building. The change of usage of building may only ended when it has been completed constructed. Some time, it stills change after the completion of building work such as further extending on building.
Whenever design of building structure on adjacent existing building. Beside the normal structure design on new building, engineer has to have some extra practical knowledge on construction works. For example, how to introduce piling work without affect the structural integrity of adjacent unit? The design of foundation work needs to ‘offset’ from adjacent unit. How to prevent collapse of earth on adjacent unit when new building has basement? All such issues are challenging to an engineer. The application of structural knowledge will mainly base on engineer experience. The more design he has gone through the more design experience he has.
For case of a client needs to extend his existing building. First of all; engineer need to study the existing building structure. Is the existing structure can directly extend for it? The client is unable to forward existing structure design and drawings. How to investigate existing structure when the existing structure information not available? How to prevent cracks on jointing location of new and old structural elements?
When dealing with change of behavior on a building such as current building is office unit and it change to hospital. How to deal with such situation? Will it require enhancing the structural of building? If require, how to do it?
For case such as moving heavy machinery into a building. There will be a route of moving the machinery to a location. How to prevent damage of existing building structure? The current design may not gather for this temporary moving load. As a structural engineer, he has to think out a method to allow temporary structure for this moving load. When a client request for assistance on investigate the cracked structure, in what position shall the engineer step into it. What should be investigated on defect structure? Where should be started to check on? How to investigate the structure when existing structure information is unavailable such as design drawings and calculation?
Nowadays, many contractors perform cost cutting on structural work. Certain may not constructing according to code of practice. Whenever a constructed building has defect, contractor may request help from engineer. How to an engineer to perform his duty on his professionalism? How to come out a remedy proposal on current structure? How to propose a cost effective way on rectify the structure?
It is quite often that contractor come out another alternative proposal on current building structure. Contractor may tell client that it is cheaper that what engineer proposed. As an engineer, what should he has to do on such issue? Sometime, contractor may telling that the specify material is unable to find in market. How to overcome such problem?
As mention all above are some of the possibilities on happening on design of structure works. The issues arise may varies on case-by-case basis. Bear in mind that when doing a structure design, it will not end until the structural has been constructed. Sometime, it will extend further during the serviceability of building. Therefore, structural engineer has to always alert on the change of behavior of building structure.
Written by scchee
Disclaimer: the above article is based on writer personal opinion on civil and structural field. It will not represent any ultimate solution of any mention subjects. Writer will not responsible for any causes arise.

Reading level: Intermediate.
(Updated 15/8/07)
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