Abstract Database

SEISMIC ASSESSMENT OF EXISTING BUILDINGS: DISCUSSION ON SEISMIC DEMAND INDEX AND DUCTILITY INDEX OF RC BUILDINGS IN BANGLADESH

MEE13611
HUQ Md. Emdadul
Supervisor: Masanori TANI
Country: Bangladesh
Abstract

Bangladesh is a densely populated country and situated in an earthquake prone area. Rapid urbanization to accommodate the increasing population results in the extensive construction of buildings. Many buildings were constructed before the formulation of the National Building Code of 1993. Also, in the absence of legal enforcement of the building code and a lack of awareness, the most buildings have been constructed without proper seismic consideration. Therefore, a huge number of earthquake vulnerable buildings exist in Bangladesh. Any time a medium magnitude earthquake may bring tremendous property loss and sufferings. As a result, it is essential to adopt a suitable seismic evaluation method including seismic demand index to judge the vulnerability of these buildings. This is a common demand of all earthquake-prone countries. Since building characteristics and construction procedures are unique to each country, selected procedures should be tested and calibrated based on characteristics of existing buildings in relevant countries.

 

In this thesis a building is taken for the seismic evaluation by the Japan Building Disaster Prevention Association (JBDPA) Standard for adaptation in Bangladesh. This method is also verified through the non-linear frame analysis. The very close the result of analysis and assessment prove the effectiveness of this method. An attempt for proposal of seismic demand index is taken based on the response spectra shown in the code to quantify the damaging power of a critical earthquake ground motion which is responsible for a critical response of a building. The seismic demand index of 0.37 is proposed in this paper for RC building in Bangladesh. The ductility index defined in the JBDPA Standard is one of the basic parameters for seismic evaluation and it depends on deformation capacity of each member. Deformation capacity depends on member configuration, axial force ratio, material strength, amount of reinforcement, confinement etc. which vary from country to country. In this thesis typical column section of existing buildings in Bangladesh is taken for sectional analysis. A comparison is conducted on the obtained ductility index through the JBDPA Standard, and sectional analysis and the applicability of ductility index are discussed. The Japanese seismic evaluation method is found very conservative at high axial force, tensile reinforcement ratio and low concrete strength.