Subsurface Identification of Campus I Universitas PGRI Yogyakarta using The Microtremor Wave Method

Abstract

Thick layers of sediment can cause Prag damage to buildings in the event of an earthquake. The subsurface identification in the Campus I area of Universitas PGRI Yogyakarta needs to be done because of the increase of new multi-story buildings in the PGRI Campus area. The identification analysis uses HVSR (Horizontal to Vertical Spectral Ratio) so that the thickness of the sedimentary layer could show in the study area. The magnitude of the dominant frequency value was measured by the microtremor method somewhere illustrates the type of soil in the study area. Based on the results of data processing, it can show that the Campus I area of PGRI Yogyakarta University is composed of thick sedimentary layers with thicknesses ranging from 26.7 m - 59.3 m. Based on the distribution map, the most adhesive sediment layer is under the area of the Rectorate building and the Faculty of Business building. These results show the similarity to the Special Region of Yogyakarta, which is an area arranged in a basin with fill material in the form of volcanic deposits.