Electronic Theses and Dissertation

Batuan merupakan material alami yang kualitas ditentukan oleh sifat fisik dan mekaniknya. Lokasi penelitian berada pada Kecamatan Babahrot, Kabupaten Aceh Barat Daya, Provinsi Aceh dengan luas 5×5 km2. Secara geografis terletak pada koordinat 3°55’42,77’’LU-3°58’24,75’’LU sampai 96°40’49,65’’BT-96°38’7,49’’BT. Berdasarkan peta geologi regional daerah penelitian tersusun atas Formasi Babahrot (Muba), Formasi Gunungapi Sapi (Tlvs), Formasi Meurah Buya (Tmm), Formasi Tutut (QTt), Formasi Meulaboh (Qpm), serta Endapan Alluvium Fluviatil dan Pantai (Qh). Daerah penelitian merupakan daerah dengan curah hujan tinggi, yang mempengaruhi kualitas batuan. Pengujian dilakukan untuk mengetahui keadaan geologi, geomorfologi, karakteristik batuan dan kekuatan batu andesit pada formasi babahrot (Muba) yang dilakukan dengan metode pengujian sifat fisik dan mekanik batuan menggunakan uji point load index dan uji cepat rambat gelombang ultrasonik. Dari hasil penelitian terdapat tiga bentang alam yaitu struktural, denudasional, dan fluvial. Berdasarkan peta lintasan, terdapat 4 STA persebaran batuan filit, 1 STA batu andesit, 10 STA persebaran litologi batu lapili, 4 STA persebaran litologi batu lanau karbonatan, 29 STA persebaran endapan lanau, dan 22 STA persebaran endapan pasir. Berdasarkan sifat fisik batuan, diketahui nilai rata-rata bobot isi asli 2,514 gr/cm3, nilai rata-rata bobot isi Kering 2,508 gr/cm3, nilai rata-rata bobot isi jenuh 2,519 gr/cm3, nilai rata-rata berat jenis semu 2,509 gr/cm3, nilai rata-rata berat jenis sejati 2,53 gr/cm3, nilai rata-rata kadar air asli 0,224%, nilai rata-rata kadar air jenuh 0,463%, nilai rata-rata derajat kejenuhan 46,25%, nilai rata-rata porositas 1,12%, dan nilai rata-rata angka pori adalah 0,0113. Pengujian cepat rambat gelombang ultrasonik pada kondisi alami memiliki nilai rata-rata 14.844,96 m/det, nilai rata-rata kondisi basah yaitu 17.438,93 m/det, dan nilai rata-rata kondisi kering yaitu 10.159,42 m/det. Batu andesit dengan rata-rata point load index 6,87 MPa tergolong kuat dan layak untuk material konstruksi.

Rocks are natural materials whose quality is determined by its physical and mechanical properties. The study area is located in Babahrot District, Southwest Aceh Regency, Aceh Province, covering an area 5 × 5 km². Geographically, its situated at coordinates 3°55’42,77’’–3°58’24,75’’ N and 96°40’49,65’’–96°38’7,49’’ E. Based on regional geological map, the study area is composed of the Babahrot Formation (Muba), Mount Sapi Volcanic Formation (Tlvs), Meurah Buya Formation (Tmm), Tutut Formation (QTt), Meulaboh Formation (Qpm), as well as fluvial and coastal alluvial deposits (Qh). The study area experiences high rainfall, which affects rock quality. The tests were conducted to determine the geological and geomorphological conditions, rock characteristics, and the strength of andesite rock within the Babahrot Formation (Muba). The methods used included physical and mechanical property tests, namely the point load index test and ultrasonic pulse velocity test. The results indicate three types of landforms structural, denudational, and fluvial. Based on the traverse map, there are 4 stations STA of phyllite distribution, 1 STA of andesite rock, 10 STAs of lapilli lithology, 4 STAs of carbonaceous siltstone lithology, 29 STA of silt deposits, and 22 STA of sand deposits. Based on the physical properties of rocks, the average values obtained are as follows: natural bulk density of 2,514 g/cm³, dry bulk density of 2,508 g/cm³, saturated bulk density of 2,519 g/cm³, apparent specific gravity of 2,509 g/cm³, true specific gravity of 2,53 g/cm³, natural water content of 0.224%, saturated water content of 0,463%, degree of saturation of 46,25%, porosity of 1,12%, and void ratio of 0,0113. The ultrasonic pulse velocity test show average of 14.844,96 m/s under natural conditions, 17.438,93 m/s under wet conditions, and 10.159,42 m/s under dry conditions. The andesite rock with average point load index value 6,87 MPa, is classified strong and suitable for construction material.