2011 : Assessment To the Local Site Effects During Earthquake Induced Landslide Using Microtremor Measurement (Case Study: Kemuning Lor, Jember Regency-Indonesia)

Dr.Ir. Ria Asih Aryani Soemitro M.Eng.

Abstract

In Kemuning Lor village â?? Jember r egency â?? East Java, The local site of geology and topographic on ground motion during earthquake ind uced landslide were investigated using Horizontal to Vertical Spectra R atio (HVSR). The microtremor m easurements were performed at the landslide area on 82 free-field measurement having 20 x 20 m dense grid. The amplification factor (A m) in 2-7 range and the soil natural frequency (fo) in 1-3 Hz were obtained from the HVSR analysis. The fo value had changed with the topographic pattern. The bedrock surface mi ght be estimated using the fo value. The A m highest value was found at the main scarp landslide and at the slope area having high topographic gradient. Variations of fo and Am parameters were indicate d as surface soil parameter â?? s variations. I n general, t he local geology effects is more dominant than the topography effect. The level of soil damage …