Search

The Horizontal-to-Vertical Spectral Ratio (HVSR) is a simple method for estimating the resonance frequency of sedimentary layers. This method can also be used for estimating the site amplification factor. By using the resonance frequency and the amplification factor HVSR method can also be used for predicting the depth of the bed rock or the thickness of sediment layer (Nakamura, 1989). This paper presents results of HVSR method applied to ambient vibrations for estimating the amplification factor of sedimentary layer. A total of 16 ambient vibration measurements were performed in the City of Semarang to predict the amplification factor for the shallow sedimentary layers.

Several methods for evaluating the effect of site specific condition of soil layers against earthquakes are presently available. Site Specific Analysis (SSA) and Horizontal-to-Vertical Spectral Ratio (HVSR) are two methods commonly used for estimating the amplification factor of soil layers above bedrock. SSA can be performed using subsurface shear wave velocities and dynamic soil properties (density, shear modulus and damping). The HVSR is a simple method for estimating the site amplification factor. Based on the time and budget requirement HVSR is more efficient and effective compare to SSA method.This paper presents result of SSA and HVSR methodscomparison for estimating the amplification factor of soil layers. Two boring locations and six single station seismometer tests were perform within Tembalang District Area.