In the context of unplanned development and risky buildings construction, it was necessary to discuss earthquake issue in order to inform the general people about the risk. Forum for Physical Development of Bangladesh (FPD) and Bangladesh Earthquake Society (BES) came together to arrange a series of round table conferences on different aspects of earthquake. Out of the five predefined round table conferences, the fifth conference was held on 21th October, 2010 at Rafflesia Hall. The conference was presided by Professor Dr. M. Shamim Z. Bosunia and moderated by Executive Director, FPD, Architect Kazi Anisuddin Iqbal. The list of the participants attended the conference is as follows;
Held on: October 21, 2010
Venue: Refflesia, House no. 02, Road no. 22, Gulshan: 01, Dhaka: 1212
- M. Shamim Z. Bosunia, Former Professor, Department of Civil Engineer, BUET.
- Kazi Anisuddin Iqbal, Executive Director, FPD, Chairman, Building For Future Ltd.
- Tanveerul Haque Probal, Director, FPD, Managing Director, Building For Future Ltd.
- Mahmudul Hassan, Member Secretary, FPD.
- Munaz Ahmed Noor, General Secretary, BES & Professor, Department of Civil Engineering, BUET.
- T. M. Al-Hussaini, Vice President, BES, Professor, Department of Civil Engineering, BUET.
- Architect G. A. Khan, Secretary General, BACI.
- Engineer S. M. Khorshed Alam, Executive Committee Member, BACI.
- Shafiqul Haque Talukder, Executive Committee Member, BACI.
- Md. Atiqur Rahman, Executive Committee Member. BACI
- Shamsul Arefin, Director, City Axis Ltd.
- Bimol C. Roy, Foundation Engineer
- Engineer Md. Shah Alam, Consultant, Crown Cement.
- Sumon Kumar Das, Engineer, Lafarge Surma.
- Dibakar Biswas, Assistant Manager, BSRM.
- Jahangir Alam Siddique, Director, Sara Brick.
The Supporting Participants:
- Muhammad Ariful Islam, Research Coordinator, FPD;
- Nazmul Ahsan, Research Officer, FPD;
- Nilima Nasrin, Research Officer, FPD;
- Mamun Chowdhury, Research Officer, FPD
The theme of the conference was “Earthquake Risk Mitigation in Bangladesh”. The preceding conference that was taken place on 3rd October 2010 had the same theme but that conference was held with different professionals. However, the speeches given by the participants attended the conference are presented below;
Kazi Anisuddin Iqbal
Thank you all for coming here to attend this meeting. We have Professor Shamimuzzaman Basunia here, our respected teacher, he will preside this session. Today we have the topic “Risk Mitigation” on which we had another session earlier. As this meeting is the most important factor regarding the structure of the building, we wanted to have more opinions from different sectors of the Building Industry. Today’s meeting is represented by major building material manufacturer companies. All of us are concerned about earthquake threat in the country. This series is a joint program with Bangladesh Earthquake Society. Professor Munaz from BES is present here; he will give a brief about the other sessions to provide you the thread of discussion.
Dr. Munaz Ahmed Noor, General Secretary, BES &Professor, Department of Civil Engineering, BUET
4 other round table conferences were arranged on earthquake issue before this one. Those were titled as;
1st RTC: Magnitude and Intensity of Earthquake Risk in Bangladesh
2nd RTC: Our Present Condition and Preparation in Respect of Earthquake
3rd RTC: Socio-economic Impact of Earthquake in Bangladesh
4th RTC: Earthquake Risk Mitigation in Bangladesh
Risk Mitigation is a very important step to manage the losses from earthquake. There are three types of mitigation measures: risk mitigation, locational mitigation and structural mitigation.
Earthquake risk can be managed by initiating some policies like insurance. If proper insurance system is in practice, people who would be affected from earthquake will be able to recover their losses in a very short time.
Locational mitigation refers to discourage/ prohibit development in risky areas. But having limited resources and scarce land, this mitigation measure is in practice in our country.
Lastly, structural mitigation is very important measure for our country that the way we can mitigate the earthquake losses/ damages effectively. This can be done in two ways: by constructing new buildings considering design standard of BNBC as well as other Building Construction Rules and also by retrofitting old vulnerable buildings.
In construction activities, the most important things are reinforcement and concrete. Nowadays, generally 60 grade reinforcement is used in construction. Now there are also some manufacturers who are able to supply 72.5 grades steels reinforcement.
In case of concrete, the minimum strength has been prescribed in order to construct earthquake resisting buildings and it is not below 3000 psi.
There are many companies manufacturing cement maintaining a very good quality. But it is a matter of sorrow that there is no standard for aggregate. There is no company to produce aggregates. In the construction sites, some unskilled labors prepare aggregate from bricks. As a result, high quality aggregates cannot be obtained most of the times. But to gain a high strength concrete, size and quality of aggregate is very important. It is revealed from a research that concrete strength can be up to 3500 to 6500 psi by using different size and quality of aggregates where other construction materials are kept same quality.
Md. Shamsul Arefin, Director, City Axis Ltd.
In our country, most of the labors engaged in construction activities are unskilled. They don’t have any institutional knowledge. Most of them lack any type of training facility. As a result, due to their deficiency of knowledge, accurate construction works cannot be done in most of the times.
There are many old structures in Dhaka city which are too vulnerable in earthquake. Measures should be taken to strengthen those vulnerable buildings/ structures.
Construction materials are to be checked properly to maintain effective quality before construction.
To prevent from earthquake losses, roles of persons/ organizations concerned in this regard should be specified properly (i.e. role of engineers/ planners/architects, role of concerned departments, role of government, role of politicians/ businessmen/ society, role of manufacturer of construction materials, role of labors, etc. ).
Many people are unaware about the devastation scale of earthquake because of necessary information. Most of them are totally unaware about what to do in order to mitigate the risk from this natural hazard. Electronic and press media can play a very important role to disseminate necessary information to general people.
Designing of structures is a very important factor in the way of constructing earthquake resistant structures. So it is to be determined in what extent the designers will consider the earthquake factors in their design.
Engineer S. M. Khorshed Alam, Consultant, Crown Cement
Nowadays people are becoming cautious regarding impact of earthquake.
We have to construct buildings and other structures considering the risk of earthquake. Our knowledge should be based on our available resources.
Researches on this issue should be promoted.
Many architects give more importance on outlook of buildings in order to make them attractive and hence give less importance on structural strengthening. This may make the buildings vulnerable to earthquake.
Existing vulnerable buildings can be strengthened by retrofitting which will be able to withstand in earthquake. But in this case, cost for retrofitting has to be considered carefully.
Most of the standards used in construction works are taken from developed countries, some of which are less effective in our country. In this case, steps should be taken to formulate standards/ formulas compatible to our country. A team consisting of experienced and younger professionals from our country can be made to formulate those standards.
Special measures should be taken for some densely populated urban areas (i.e. Old Dhaka, Mirpur, etc.) to operate emergency activity after earthquake.
Engineer Md. Shah Alam, Consultant, Crown Cement
Good quality construction materials have to be produced to construct seismically resistant structures.As construction of a sound structure is especially depended on the quality of materials. Proper facilities are needed to ensure the quality.
Building and structure should be designed following the codes and standards according to BNBC and Building Construction Rules.
M.I. Cement Factory Limited (Crown Cement) produces two types of cements: CEM-I, 42.5N (OPC) and CEM-II (AM), 42.5 N (PCC). Compositions of raw materials are tested before importing and during production. Quality of cement is strictly controlled. In the production procedure, we consider the strength required to protect buildings from earthquake. But I think, there are many manufacturers who are not so cautious in this matter.
In our country, there are many companies which produce cement maintaining very good quality. Moreover, most of the cement companies maintain a minimum standard; they should produce high quality cement which might help to withstand building in earthquake.
Jahangir Alam Siddique, Director, Sara Bricks Limited
Brick is a very important component among all other construction materials. So, strength of brick is significant in order to make strong buildings.
We manufacture brick maintaining the minimum strength of 4000 psi which is very useful to make earthquake resistant building. Our company produces brick through burning with gas. It is the procedure by which quality bricks can be manufactured. There are several companies which follow the same process. But there are many who do not. All brick manufacturers should be more cautious and responsible in this regard. There should be a minimum standard of quality that every brick manufacturer must follow. It will be helpful in the way of making strong buildings which could be able to withstand damages from earthquake.
Dibakar Biswas, Assistant Manager, BSRM
The quality of construction materials is very important in constructing sound structures that could resist affects from earthquake. But alone good quality construction materials cannot provide fine construction. Skilled manpower and their sincerity is another important factor in this regard. Without skilled manpower/ labor it is not possible to maintain all the construction works accurately and on the other hand, without the sincerity, it is not possible to extract fine works even from the most skilled workers.
Many people engaged in construction works think that alone high strength steel/ reinforcement may ensure strength of the building. A building with high strength steel but lower strength concrete and other materials will ultimately lessen the strength of the structure. So all the construction materials must be of good quality to get desired strength of the structure.
Engineer Shafiqul Haque Talukder, Managing Director, Starlight Services Limited
Quality of aggregates (fine/ Course) has to be maintained properly along with the quality of the reinforcement and concrete. Aggregate industry can be established separately to supply quality products.
On site facilities should be provided to carry out concrete test.
There are lacking in the supply of skilled labor in construction works. So proper training facilities should be initiated to make them skilled in this sector.
Concrete strength increases if water and cement are mixed in accurate proportion. But due to the deficiency of knowledge and cautiousness among workers, perfect mixing cannot be done most of the times. So necessary measures are required to make the workers more cautious.
Proper initiatives are required to make the general people aware about the risk of earthquake. Electronic and press media can take an important part in this regard. Necessary educational programs and/or training facilities on earthquake can be arranged in all educational institutions including schools, colleges and universities. If necessary, these types of programs/ training facilities can be arranged in every locality.
Engineer Ziaul Ahsan, Engineer, BSRM
Quality must be controlled for every raw material in order to construct strong buildings/ structures.
Every developer (both public and private) should work with honesty considering every building rules and regulations in order to lessen the earthquake risk.
Besides public engineering universities, there are many companies who have facilities for testing construction materials. Other developers/ companies may test their materials (rod, cement, etc.) from those companies.
Engineer Md. Atiqur Rahman, Managing Director, The Civil Engineers Limited
In construction works, design is a very important component. Sometimes we engage in construction works for the government. In construction activities, we follow the prescribed guidelines determined by the government. Sometimes we find problems in design but can’t do anything as they are prefixed.
Supervision of construction activities is also very weak and inappropriate in our country. Some companies like us undertake supervision works during construction with their own initiatives. But it is not common for all.
In developed countries, generally a third party is appointed to undertake the supervision works which surely increase the efficiency of construction activities. We should follow their practice in order to gain a sound structure.
Architect G. A. Khan, Secretary General, BACI
In most of the earthquake prone countries, especially in Japan, some basic instructions and trainings are regularly given to the students of schools/ educational institutions so that in the event of an earthquake, they might be able to behave and act appropriately to minimize the injury and physical harm.
Like them, we can initiate drills and trainings to educational institutions (i.e. schools, colleges, universities, etc.) and other organizations (i.e. offices, commercial centers, etc.). At first we can start from distributing small booklets containing instructions about what to do during and after earthquake. This booklet should be published in bangali with the simplest language and with necessary illustrations so that it is easily comprehensible to all classes/ ages of people. It should be prepared and distributed free of cost to all institutions, social organizations and NGO’s.
Civil defense groups should be organized in the neighborhood level, especially in the densely populated urban areas so that in the event of a major earthquake, organized rescue and first aid can be provided by the local teams at the local level.
Engineer Sumon Kumar Das, Engineer, Lafarge Surma
Cement manufacturers are always sincere in quality control. Lafarge Surma conduct quality test after production regularly. Cement quality may be deteriorated due to adulteration during the period of distribution. In that case, if the individual builders should conduct quality test before use. Developers usually verify cement quality during construction. However, individual builders never verify cement quality. Consequently they construct risky buildings. Moreover, all the builders prepare cement concrete where ingredients ratio is determined in terms of volume. I think it will be more appropriate if the ingredients ratio is determined in terms of weight (e.g. Kilogram).
Engineer Bimol C. Roy,
Bangladesh is a developing country. Construction and design works are of an average standard. There are lacking in detailing. Sometimes these designs have details in drawing but not implemented in the field level. The workers in the construction activity don’t have any training to perform properly. We have to train these people to get better outcome. Also third party inspection is very much required in these design and implementation process.
Dr. Tahmeed M. Al-Hussaini, Professor, BUET & Vice President, BES
BNBC is very much important guideline to design and construction procedure of building. However, the BNBC is now being updated with incorporation of codes for earthquake. But this code should be different for different places such as Dhaka, Chittagong, Sylhet, etc. The prevailing code was done considering that, building could have damage but may not collapse during the shaking of earthquake. There must be available data of drawing, building and testing. There should also be a checklist of construction procedure. This checklist should be detail and strictly followed by the constructors and supervisors. Also in any project there must have provision for incorporating the name of the design and consultant in drawing and reports.
Dr. M. Shamim Z. Bosunia, Professor (Retired), Dept. of Civil Engineering. BUET
We cannot mention a particular building that it is completely earthquake resistant structure at any circumstances. That is because; there is no structure which surely can withstand certain magnitude of earthquake. Developers should construct buildings considering prescribed standards designated by BNBC and Building Construction Rules which could resist strong damages from earthquake.
In our country, most of the buildings are constructed without consideration of building construction rules and regulations. High rise buildings, in which construction rules and regulations are followed, may be designed only considering the vertical load. For high rise buildings, lateral load is also very important. So in design, lateral load (wind load) must be considered along with the dead load and live load (together vertical load) in order to construct strong buildings.
Sizes of column and beam are very important factors and must be designed carefully. In many structures, size of beam is heavier than that of column. But this dangerously makes the structure more vulnerable to earthquake. Tie between column and beam is another important part of the structure. A little modification in tie design can even strengthen the structure and lessen the vulnerability of the structure to earthquake. In our traditional concept, such details were ignored or neglected.
In our country, structural detailing is so poor. There are many designers who don’t even prepare any structural sections. But structural detailing is very important to perform the construction activities accurately. It is also important to justify the quality of the structure.
The quality of concrete is more important than other construction materials to ensure a strong structure. So in order to gain the best quality, mixing of raw materials (cement, rod, brick chips, etc.) should be in appropriate proportion. Quality of raw materials should be appropriate.
Cement produced in our country does not have any expiry date by which effectiveness would be measured easily. Manufacturers should publish expiry date in each bag along with other information in order to understand the quality easily. Sizes of aggregates are also important to maintain. Constructors must know which size of aggregate they should use in which part of construction.
Every Developer must conduct soil test before any construction. In our country most of the individual developers do not conduct soil test. Nowadays many developers set soil test report but most of the procedure of their test is subject to controversy. This is either because of the limited knowledge of the concerned workers or lacking of honesty among them.
Public and private developers should incorporate importance factor while designing important public buildings like hospitals, educational institutions, fire brigades, public offices and commercial centers, etc. where mass people going to take shelters in disaster. This importance factor should be 1.3 for above mentioned public buildings.