Gazali, Imam (2017) Estimasi Kecepatan Gelombang Geser (Vs)Berdasarkan Inversi Mikrotremor Spectrum Horizontal to Vertical Spectral Ratio (HVSR)Studi Kasus: Tanah Longsor Desa Olak Alen, Blitar. Undergraduate thesis, Intitut Teknologi Sepuluh Nopember.
Preview |
Text
3713100015-Undergraduate_Theses.pdf - Published Version Download (7MB) | Preview |
Abstract
Gerakan tanah merupakan bencana yang sering terjadi di kabupaten Blitar. Salah satu daerah yang sering terkena dampak oleh peristiwa tersebut adalah desa Olak-Alen, yang ditandai dengan adanya longsor. Hal ini dikarenakan pada daerah tersebut terletak pada kondisi geologi yang tersusun dari tuff dan pasiran yang mempunyai potensi bahaya yang lebih besar terhadap efek intensitas gerakan tanah. Untuk mengetahui karakteristik lapisan tanah yang rentan terhadap bahaya gerakan tanah dilakukan pengukuran mikrotremor dengan metode HVSR. Kemudian data mikrotremor dianalisis untuk mendapatkan kurva HVSR yang akan digunakan untuk mengetahui penyebaran kecepatan gelombang gesernya (Vs) melalui proses inversi. Berdasarkan hasil penelitian didapatkan nilai frekuensi natural 1.7-3.7 Hz, Puncak HVSR 2-9 dan Indeks Kerentanan 1.5-44.7. Daerah yang diduga sebagai bidang gelincir memiliki nilai kecepatan geser 200-300 m/s yang di klasifikasikan sebagai tanah tipe D berdasarkan SNI 1726-2012 dan tipe C menurut Eurocode 8. Sedangkan bedrock pada penelitian ini memiliki nilai kecepatan geser 750-1200 m/s yang tersebar pada kedalaman 50-60 meter.
===========================================================================================
Ground motion is a disaster that occur frequently in blitar. One of the most damaged areas in blitar is Olak-Alen village, where landslide caused by ground motion occur frequently. This is due to olak-alen’s geological condition that consist of tuff and sand that has bigger potention of damage toward effect of ground motion intensity. To know the characteristic of subsoil that vulnerable toward danger of ground motion, microtremor measurement is done using HSVR method. Then, microtremor data is analysed to get HSVR curve which is used to get the spreading velocity of ground’s shear wave velocity (Vs) through inversion process. Based on the result of this research, natural frequency 1.7-3.7 Hz, HSVR peak 2-9, and vulnerability index 1.5-44.7 are obtained. The suspected area of slip has a shear velocity value of 200-300 m / s which is classified as type D ground based on SNI 1726-2012 and type C according to Eurocode 8. While bedrock in this study has a shear velocity value of 750-1200 m / s which spread over 50-60 meters deep.
| Item Type: | Thesis (Undergraduate) |
|---|---|
| Uncontrolled Keywords: | Olak-Alen village, Landslide, HVSR, Shear wave velocity (Vs) |
| Subjects: | Q Science > QE Geology > QE601 Geology, Structural T Technology > TA Engineering (General). Civil engineering (General) > TA749 Soil stabilization |
| Divisions: | Faculty of Civil Engineering and Planning > Geophysics Engineering > 33201-(S1) Undergraduate Thesis |
| Depositing User: | Imam Imam Gazali |
| Date Deposited: | 11 Aug 2017 07:34 |
| Last Modified: | 05 Mar 2019 02:27 |
| URI: | http://repository.its.ac.id/id/eprint/42049 |
Actions (login required)
 |
View Item |