The experts, including structural engineers, geologists, seismologists, building contractors, construction engineers, soil engineers, and academicians of Sindh, have formed a committee to review earthquake zoning for Karachi and Sindh to assist Sindh government for establishing realistic earthquake zone.
This was stated by Association of Consulting Engineering Pakistan (ACEP) President Zaheer Mirza, while speaking at a press conference, organised by ACEP to apprise about 'safety from earthquake,' at a local hotel here on Saturday.
Mirza said that ACEP had earlier arranged a meeting where Association members, Karachi Building Control Authority (KBCA), Association of Builders and Developers (Abad), All Pakistan Contractors Association (APCA), Sir Syed University, Urdu University, NED University, Institution of Engineers Pakistan-IEP participated and discussed the situation.
After a detailed discussion it was agreed to form a committee comprising Zaheer Mirza as chairman, Karamat Ullah Chaudry as vice-chairman, Dr Syed Iqbal Mohsin as co-chairman and Siddiq Essa, as co-ordinator. Besides this, representatives from all the concerned organisations were taken into the committee as its members.
Mirza pointed out that after the October 8 devastating earthquake in Azad Kashmir and NWFP, a lot of emphasis is being laid by several committees in Karachi on the geological faults around and in the vicinity or near Karachi. It may be recognised that such faults need to be proved "active faults" to consider them as posing hazard of seismic activities. No scientific studies have been conducted about the nature of these faults and their activities, movements, etc to declare them as 'active' or 'dormant' faults.
He said, in fact, the entire globe, including sea-beds are criss-crossed by geological faults and rupture lines on its crust. Most of them are 'dormant' faults posing no hazard and having no seismic hazard history. In total absence of any modern scientific instrumentation available in Pakistan, the study of the faults from vague visual studies to write or talk confidently about the magnitude of hazards posed by them, may be tantamount to mere guess works.
Mieza said the UN conducted a seven-year research (from 1992) supported by seismologists of 133 countries and have published seismic hazard maps for regions of entire world through US Geological Survey (USGS) (available on web: usgs.gov). These maps indicate North Balochistan - Quetta, Chaman, Zhob, etc and regions in Himalayas, Hindukush and Pamir ranges and their foot regions - Chitral, Peshawar, Gilgit, Islamabad, Nepal, Assam, etc, as seismically most active regions in the world.
The USGS/UN maps indicate Karachi is in Upper Moderate Hazard Zone. Hence based on the unconfirmed non-conclusive scientific research, for Pakistani seismologists and other concerned professional recommending Karachi to be upgraded to Zone 3 (PGA 0.36g) may be hasty and the proponents of such recommendations may be required by other professionals and agencies to backup such decisions by the record of Instrumental Data and Documents of Research like those published by UN Research Programme.
Stipulating the seismic zoning for the cities and regions need to be under government laws and regulations. These regulations are based on a Building Code approved by federal as well provincial legislatures. Therefore, ACEP has consistently emphasised that the future Building Code should be compiled by the committee of seismologists, geologists, structural engineers, architects and engineering-builders.
This Code Committee like in most other countries of the world should comprise experts from the government as well private institutes and consulting firms. To assign hurriedly, the compilation of a national document of vital importance (to complete in 30 days) by a single government-owned consulting company will be tantamount to that company unilateral decision on the engineers, architects, and consumers of the entire nation.
Such exercise is likely to draw protests, challenges and perhaps litigation from the professional bodies connected with engineering and construction. Therefore, a proper committee be structured.
Till a proper code as suggested in Para 4 above is drafted, Karachi which has approved Seismic Regulations since 1984 (Revised in 2000) stipulating Karachi in Zone 2B should be continued.
For the rest of the country US/UN Seismic Hazard Maps should be adopted for zoning. For structural design the present practice of adopting ACI-318 and ICBO-2003 should be continued by the engineers for the building design till a proper Building Code of Pakistan is processed and legislated, he said.
Mirza suggested that a survey should be conducted by the KBCA that has the structural plans of all the buildings built since 1975. It is not practical to re-strengthen the buildings of the city of Karachi, which are not designed to meet the seismic safety standards. However, such surveys termed as "Seismic Resistant Assessment of Buildings". The codes allow pre-regulation (Seismic Code) structures certain waivers and relief for partial re-strengthening. This was originally initiated by San Francisco after 1906 EQ which had destroyed major part of the city. Therefore, a digitised map should be prepared for such buildings, indicating the percentage of seismic resistant capacities for each building compared to the Code requirement.
Such assessment will generate a blue-print of nature of average structural hazard the city is prone to an earthquake event. It may also give a handle to structural engineers to propose some kind of economic retrofitting measures to mitigate life hazard due structural collapse during earthquake.
He said ACEP has prepared its recommendations to the government, as a National Building Code be developed through a Committee consisting of Public & Private Sectors representation (Geologist, Seismologist, Structural Engineers and Architects & Engineering Builders) and legislated after broad-based relevant technical experts' consensus.
The Sindh government should base their decision on zoning of province's major cities on the basis of recommendations of the broad-based committee. As a safety measure for the already constructed private buildings and essential public buildings eg hospitals, fire brigade, civil defense, police stations and other structures needed for disaster management, he said, adding these may be surveyed and strengthened as necessary.
All building control agencies must ensure that all designs are earthquake-resistant and quality control during construction is strictly made. The maintenance of buildings must be made mandatory for the owners of all buildings for better safety and outlook as well as a procedure of intermittent inspection be devised.
The other members of the experts committee are Karachi Building Control Authority, Engr. Muhammad Shafiq - Controller of Building (Structure), NED University of Engineering & Technology, Professor Sahibzada Farooq - Chairman Civil Engineering, Sir Syed University - Dr S.M. Makhdumi (Chairman Civil Engineering), University of Karachi - Mr. Nayar Alam Zaigham, Geologist, Quaid-e-Azam University, Islamabad, Ms. Shazia Asim-Seismologist, Institution of Engineers Pakistan (IEP) - Representative, Institution of Architects of Pakistan (IAP) - Representative, A. Razzak Loya, Senior Structural Consultant, Mushtaq Dawood, Senior Structural Consultant, Engr. Arif Kasam, Hon. Treasurer, ACEP, Al-Kazim Mansoor, Soil Engineer, Association of Builders and Developers (nominee), Association of Builders and Developers, South Zone (nominee), All Pakistan Contractors Association - Representative, Geological Survey of Pakistan - representative and Meteorological Department, Karachi.
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