KLASIFIKASI MASSA BATUAN RMI (ROCK MASS INDEX) UNTUK ANALISIS KESTABILAN LERENG DENGAN METODE ELEMEN HINGGA
Abstract
ABSTRAK - Pada penelitian ini akan digunakan studi klasifikasi massa batuan terhadap lereng alami, yaitu klasifikasi RMi dengan objek penelitian pada lokasi lereng batuan yang berada di Cipatat, Kabupaten Bandung Barat, Provinsi Jawa Barat. Lokasi penelitian memiliki morfologi bentuk lereng terjal dengan litologi dominan berupa batugamping. Klasifikasi RMi ini jarang digunakan karena memiliki beberapa parameter yang cukup rumit untuk dilakukan pembobotan. Untuk mendapatkan nilai bobot dari klasifikasi massa batuan dilakukan pengamatan lapangan dengan scanline dan pengambilan sampel batuan utuh. Hasil properti keteknikan dari klasifikasi massa batuan RMi dianalisis menggunakan metode elemen hingga (finite element method). Massa batuan di lokasi penelitian memiliki litologi dominan berupa batugamping kalkarenit, kalsirudit, dan kalsilutit dengan tingkat pelapukan rendah hingga sedang. Bobot massa batuan berdasarkan klasifikasi RMi berkisar 2,09 – 6,228 (high). Properti keteknikan dari massa batuan dari lima lokasi memiliki modulus deformasi (Em) berkisar 3.068 – 11.550 MPa, kohesi (c) berkisar 0.236 – 2.334 MPa, sudut geser dalam (ɸ) 37o – 57o, dan kuat tarik (σt) berkisar 0,04 – 0.80 MPa. Dari hasil analisis tersebut, properti keteknikan dari klasifikasi massa batuan RMi dapat diterapkan untuk analisis kestabilan lereng menggunakan metode elemen hingga. Rekomendasi penyangga dari klasifikasi RMi cukup signifikan berpengaruh pada faktor keamanan dan perpindahan kestabilan lereng.
Kata kunci: Klasifikasi massa batuan RMi, kestabilan lereng, volume blok, metode elemen hingga
ABSTRACT - In this research, a rock mass classification study on rock slopes will be used, the RMi classification with the research object on rock slope locations in Cipatat, West Bandung Regency, West Java Province. The research location has a steep slope morphology with dominant lithology in the form of limestone. The RMi classification is rarely used because it has several parameters that are quite complicated to weight. To obtain weight values from rock mass classification, field observations were carried out with a scanline and intact rock samples were taken. The results of the engineering properties of the RMi rock mass classification were analyzed using the finite element method. The rock mass at the study site has dominant lithology in the form of calcarenite, calcirudite, and calcilutite limestones with low to moderate weathering levels. The rock mass weight based on the RMi classification ranges from 2.09 to 6.228 (high). The engineering properties of the rock masses from five locations have a deformation modulus (Em) ranging from 3,068 – 11,550 MPa, cohesion (c) ranging from 0,236 – 2,334 MPa, internal friction angle (ɸ) 37o – 57o, and tensile strength (σt) ranging from 0,04 – 0.80 MPa. From the results of this analysis, the engineering properties of the RMi rock mass classification can be applied to slope stability analysis using the finite element method. Support recommendations from RMi classifications have quite an effect on the safety factor and slope stability, while another recommendation to make the slope more stable is to make a cut-off slope for each slope so that the slope is more stable.
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DOI: https://doi.org/10.31315/jmtg.v13i3.9397
DOI (PDF (Bahasa Indonesia)): https://doi.org/10.31315/jmtg.v13i3.9397.g5211
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