INVESTIGASI GEOLOGI POTENSI LONGSOR BERDASARKAN ANALISIS SIFAT FISIK DAN MEKANIK BATUAN DAERAH BANJARSARI, DAN SEKITARNYA, KABUPATEN BREBES, PROVINSI JAWA TENGAH
Abstract
ABSTRAK: Lokasi penelitiannterletak di Daerah Banjarsarindan sekitarnya, Kabupaten Brebes, Provinsi Jawa Tengah. Secara geografisldaerah penelitiansberada padaskoordinat S07o17’34.1” LS - S07o22’ 24.1” LS dan E108o59’37.3” BT - E109o04’30.5” BT. Diketahui dariltopografinya, daerah Banjarsari danssekitarnya, memiliki kemiringanldan ketinggian mulaildari 0 mdpl sampaildengan wilayahlperbukitan hinggalketinggian ±700 mdpl. Sebagian besarldaerah penelitian didominasiloleh wilayahnperbukitan yangimemiliki kelaslkemiringan denganllereng miringlhingga cukup curam danlrawan longsor. Faktor lainlyang mempengaruhiikestabilan lerengipada daerah telitianiantara lainiadalah sifat fisikidan mekanikibatuan, litologi,ikemiringan lereng,smorfologi,svegetasi, danscurah hujan. Metode yangndilakukan yaituianalisa ujilgeser langsungluntuk mendapatkanlnilai kohesispada batupasirsunconsolidated dengansbentuk butir sub-rounded – roundediyang bertujuaniuntuk mendapatkanlsifat mekanikibatuan denganlberdasarkan analisislsifat fisik batuannuntuk mengetahuispotensi longsor. Penelitian inisbertujuan untuksmengetahui FaktorsKeamanan darindaerah penelitianndengan menggunakanlklasifikasinmenurut Bowles, 1984nsehingga didapatkannberbagai hasillpada daerah penelitianiyang didominasi oleh kriteriaiKritis (longsoran pernah terjadi) dan Labil (longsoran bisa terjadi atau sering terjadi) denganigerakan tanah Debris Slide.
Kata Kunci: Investigasi geologi, Kestabilan Lereng, Longsor.
ABSTRACT: The research is located in the Banjarsari and surrounding area, Brebes, Central Java Province. Geographically, the reseacrh area is at coordinates S07o 17 '34.1 "LS - S07o 22' 24.1" latitude and E108o 59 '37.3 "E - E109o 04' 30.5" East.Based onits topography, Banjarsari Region and surrounding areas, has a slope and an altitude ranging from 0 masl up to the hills to a height of ± 700 masl. The reseacrh area is dominated by the hills which has a slope class with fairly steep slope sloping up to landslides. Another factor that affecting the stability of slopes in the area situations include physical and mechanical properties of rocks, lithology, slope, and morphology, vegetation, and rainfall. The method used is the analysis of direct shear tests to get the value of cohesion in unconsolidated sandstones with sub-rounded grain shape - rounded aiming to obtain the mechanical properties of rocks with based on analysis of physical properties of rocks to determine the potential for landslides. This study aims to determine the security factor of the study area by using classification according to Bowles, 1984 to obtain various results of the research area is dominated by Critical criteria and unstable ground motion is Debris Slide.
Keywords: Investigation of geology, Slope Stability, Landslide.
