SUMMARY

Computing synthetic seismograms for microzonation study of the old Hà Nội area

Thái Anh Tuấn, Nguyễn Đức Vinh

In this paper we present the results of hybrid method to compute synthetic seismograms with a scenario of an earthquake occurring at the Red River Fault with M = 6.5, hypocentre depth of 10 km, focal mechanism parameter with dip = 80⁰, strike = 312⁰. Ten geological sections crosscutting the old Hà Nội area are taken to compute synthetic seismograms.

From the results of synthetic seismograms along ten profiles we can see that:

The maximum ground acceleration (Amax) for horizontal component varies from 150 to 545 cm/s², radial component varies from 30 to 151 cm/s², vertical component varies from 23 to 104 cm/s². The comparison of Amax with the intensity scale MM (modified Mercalli scale) shows that the expected intensity is in the range from VI to IX.

Response spectra ratios (RSR) reaches the largest values in the frequency range from 1.0 to 3.0 Hz (corresponding with period from 0.33 to 1 s). The largest site amplification is observed at loose soil and thick sediment areas.

Người biên tập: GS.TSKH Mai Thanh Tân.