Preliminary Estimation of Engineering Bedrock Depths from Microtremor Array Measurements in Solo, Central Java, Indonesia

Sorja Koesuma (Department of Physics, Sebelas Maret University, Surakarta)
Mohamad Ridwan (Research Institute for Human Settlement (RIHS), Ministry of Public Works)
Andri Dian Nugraha (Global Geophysics Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132)
Sri Widiyantoro (Global Geophysics Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132)
Yoichi Fukuda (Graduate School of Sciences, Kyoto University, Kyoto, Japan)

Journal of Mathematical and Fundamental Sciences
Vol. 49 No. 3 (2017)

In the last decade the city of Solo, located in Central Java, Indonesia, has grown significantly and become a major city. Many industries and hotels have been built in the city and its surroundings. This study aimed to determine the engineering bedrock depths in Solo, an important parameter in seismic hazard analysis. The microtremor array method was used to obtain 1D S-wave velocity profiles and construct layer depth maps. The spatial autocorrelation (SPAC) method was used to calculate the dispersion curves, while the S-wave velocity structure was derived using a genetic algorithm (GA). The results of the S-wave velocity structure in Solo show that there are four stratigraphic layers, where the engineering bedrock depths in Solo exist within the range from 145 to 185 m. The shape of the bedrock basin is elongated in an east-west direction.