Andhika Sahadewa
Complete abstract bandung, west java capital, with sequence, geological order, population, and infrastructure growth, requires a detailed study of the risk of earthquake hazards for the development of a very important mitigation plan to support sustainable infrastructure and the assisted environment as part of the seismic danger of risk studies, It is necessary to evaluate the depth of the base rock and geomaterial over it. Unfortunately, this evaluation has not been done thoroughly and systematically for the city of Bandung. Arrik Mikrotremor Analysis is a geophysical method that generally utilizes period-period waves produced from passive or microtremor background noise. Because of the long-term wave nature, the microtremor is able to investigate the layer deep below the ground and capture the existence of the basic rock layer. The active method that utilizes the resulting waves by losing weight from the height will require very high energy to create a wave of jongperiod to investigate a deeper layer. Thus, for surveys to a greater depth, the microtremor method is more cost-effective and time-saving compared to the active method. And any method that requires conventional Deep Boring. The microtremor method starts with collecting microtremor records simultaneously at some point. Records collected are then processed with a spatial autocorrellation method to obtain a dispersion curve, which is a curve that shows the relationship between the speed of microtremor and frequency phase. Finally, the inversion process is carried out on the dispersion curve to get the estimated sliding wave speed profile. In this study, the microtremor array analysis was proposed to evaluate the depth of the basic rock in the city of Bandung and characterize overlying geomaterial in terms of sliding wave speed. Two locations in the city of Bandung were selected. Test results, such as background noise records, dispersion curves, and 1-day sliding wave speed exposure are served in this manuscript. The presence of a basic engineering rock layer, characterized by sliding wave speed higher than 750 m / s, estimated at depth 169 - 182 m below the ground. Based on the results of this study, the mikrotremor array analysis application in evaluating the depth of the base rock and the geomaterial wave of geomaterial speed is quite satisfying. This method is recommended to be applied further in more locations in the city of Bandung to develop a comprehensive basic rock map. Keywords: background noise; Basic rock depth; dispersion curve; Microtremor array analysis; passive method; seismic danger; Sliding wave speed.
Application of appropriate technology
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