KARACHI: Experts call for raising quality of construction
By Mukhtar Alam
KARACHI, May 8: Senior academics and researchers from Japan at a seminar on Monday shared their works on earthquakes in Japan and Pakistan and emphasised for enhancing the awareness among workmen and improve quality of construction to avoid collapse of many buildings in the event of calamity.
They also called for having seismic evaluations of buildings and better understanding of buildings and undertaking rehabilitation of vulnerable buildings in the country.
The seminar on “Restoration and reconstruction of the areas affected by earthquake on October 8” was organised by the Cowasjee Earthquake Study Centre, Department of Civil Engineering, NED University of Engineering and Technology in collaboration with Japan Society of Civil Engineers and Architectural Institute of Japan and the Japan International Cooperation Agency.
The chairman of Karachi Port Trust, Vice-Admiral Ahmad Hayat, who was the chief guest at the seminar, said that implementation of good engineering practices and disaster conscious designs could prevent and minimise the damages and the consequent loss of human lives. “Availability of sophisticated heavy machinery, expeditious mobilisation of resources and smart engineering techniques go a long way in post-disaster restoration and reconstruction,” he added.
Referring to the participation of scholars from Japan, he said that Japan was considered as the cradle of knowledge in earthquake engineering. Located virtually on a volcanic island, Japan, is often termed as the quintessence of earthquakes, he added, saying it was therefore not surprising that some of the best known technology to avert and fight this adversity of earthquake had grown from Japan.
Prof Kazuo Konagai said that an intense earthquake (M 7.6) occurred in north eastern frontier area of Pakistan, about 90-km NNE of Islamabad at 8.28(PST) on Oct 8, 2005. In terms of death toll and its impact on society, this massive earthquake could be compared with Kanto killer earthquake of 1923 occurred in Japan, whose magnitude was later estimated to have been between 7.9 and 8.4, he added.
Referring to some JICA projects, he said that those included restoration of four bridges on the Jehlum River, rehabilitation of Muzaffarabad and designing prototype seismic resistant and barrier-free basic health units in the NWFP and the AJK.
Prof Omer Aydan said that one of the most distinct characteristics of 2005 Kashmir earthquake was widespread slope failures all over the epicentre area, which caused extensive damages to housing and structures founded on slopping soil deposits. Extensive natural and cut slope failures occurred along Neelum, Jhelum and Kun valleys, which obstructed both river flow and roadways, he added, saying many slop failures associated with highly sheared and weathered dolomite limestone occurred along the presumed surface of the earthquake fault.
Some peculiar soil slope failures were observed in both Balakot and Muzzaffarabad. These slopes failures occurred in conglomeratic soil deposits with rounded large cobbles, which are products of the past glaciation's' period, he remarked and said that since the slope angles were quite steep, these failed on surfaces involving partly vertical tensile cracks and curved shear plane.
He advised that if the construction of buildings next to slopes in relation to site selection for resettlement and re-construction was allowed, there should be a safety zone between the slope crest and allowable construction boundary.
Talking of some tectonic studies in relation to Karachi, Prof Aydan feared that there were seismic hazards for Karachi region as well in future, and as such there was need of establishing more and stronger monitoring stations. He said that seismic area in Karachi was increasing day by day, which also warned that a tsunami was in area near Karachi.
Prof Yoshiaki Nakano said that damages observed in the quake affected areas, including Islamabad, Abottabad, Battal, Balakot, Muzaffarabad, etc could be attributed to material quality, reinforcement details, construction practice of beam-column joints etc. He said that safety evaluations of buildings exposed to intense shaking were also necessary to identify their post-earthquake safety to future events including aftershocks.
Dr Takao Nishikawa, Dr Toshikazu Hnazato, Dr Hiroshi Imai, Prof Sarosh H Lodi and Dr A Samad Khan also spoke at the seminar.
