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The Standard Soil Profile Type Map of Pakistan


Fawad Najam
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The existing Building Code of Pakistan (BCP) enforces a typical short-period shaped, UBC 97-based response spectrum which is a function of seismic coefficients Ca and Cv. These coefficients are further dependent on seismic zone factor (Z) and soil profile type. The BCP provides a table for seismic zones derived from a relatively recent PSHA study for all tehsils in the country, however, it doesnt provide the Standard Soil Profile Type Map to be used in conjunction with seismic zones. Is there any standard soil profile type map (or Vs30 map) for Pakistan? There are few individual studies on this topic, however, I am interested in a widely-accepted definition/assumption of soil profile types down to tehsil level.

Thanks 

Fawad

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Dear fawad najam! The methodology for seismic design has been radically changed in ASCE7-05 from that used in earlier codes like UBC 1997,the governing parameter for development of response spectrum are now the ss (short period accelaeration) and s1(one second spectral acceleration)

ss and s1 can be derived from the peak ground acceleration(PGA) using empirical relationshops based on performance level(EUROCODE 8).

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14 hours ago, ILYAS said:

Dear fawad najaum! The methodology for seismic design has been radically changed in ASCE7-05 from that used in earlier codes like UBC 1997,the governing parameter for development of response spectrum are now the ss (short period accelaeration) and s1(one second spectral acceleration)

ss and s1 can be derived from the peak ground acceleration(PGA) using empirical relationshops based on performance level(EUROCODE 8).

Thanks ILYAS

Yes we can somehow come up with ss and s1 values for a certain individual project's site in Pakistan. But it would either be based on some empirical relationship (I doubt the adequacy of using such relationships due to a number of unknown variables involved e.g. the uncertainty in quantifying the ability of local soil to amplify the ground acceleration at site etc.) or based on some international standard or guideline as suggested in the next comment (which again is not intended to provide a detailed seismic hazard within a country).

I was asking for a standard seismic hazard established by the BCP. The reason I am specifically interested in this is as follows.

I was making a web-based application which would provide an interactive online facility to visualize the seismic hazard in Pakistan. The starting point would be to show a benchmark hazard (in the form of various seismic parameters, spectra etc.) which is duly standardized by the country's building code. Later, I plan to incorporate more detailed and recent studies, or may be develop a comparative kind of database to visualize various attempts (e.g. GSHAP, PMD, individual researchers etc.) to quantify seismic hazard within country. 

Obviously, the BCP should have been updated to use spectral acceleration as key hazard parameter instead of PGA. With this update, it should have ideally provided the ss and s1 values for whole country down to tehsil level. However, currently it seems like asking for moon.

If you find any information or digitized data related to this, please help. 

Thanks

Fawad

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  • 6 months later...

Dear Fawad, 

Dr Mona Liza of Quaid e Azam University Islamabad has done a lot of work on this. You can also consult Dr Qaiser of Uet Peshwar and Dr Shoaib Ahmad (Zeinth International). He is working on the same thing

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