October 2005 earthquake and safe geotechnical design of structures in Pakistan
Sohail Kibria*, Junaid Ahmad and Sadaf Saeed
GT and GE Division, National Engineering Services Pakistan (NESPAK), Lahore, Pakistan
* Email: skibrias@yahoo.com
The occurrence of an earthquake invokes an entirely unique type of loading environment, which the structure may not be able to withstand, if not properly designed for the same. As a result, the structures on flat ground as well as on sloping ground and in different subsurface conditions require different mitigative measures at the design stage, for their safe performance. The October 08, 2005 earthquake caused a phenomenal destruction in the northern Pakistan. However, the lessons learnt from it and the ensuing geotechnical safety systems are required to be implemented in the entire country, indiscriminately.
This paper deliberates on the salient geotechnical design requirements that would ensure safe design of structures for various ground conditions. The safe geotechnical design of structures in Pakistan necessitates that the following minimum requirements have been adequately met, as applicable:
- Soil zone assignment, based on sufficient geotechnical investigations, covering both static and dynamic aspects
- Selection of site with acceptable hazard zone
- Mitigation of liquefaction risk
- Control over ground settlements under seismic loading
- Control over resonance in the foundation design
- Measures to increase dampness
- Design compatible to the sensitive soils
- Improvement / stabilization of soils and rocks
A consideration of the above geotechnical aspects at the design stage of structures will definitely go a long way towards ensuring safe and economical design of structures, against earthquake loading. |
