Analisis Stabilitas Lereng Pembangunan Embung Bena dengan Geostudio

Abstract

Embung Bena dirancang sebagai solusi penyediaan air di Desa Bena, Kabupaten Timor Tengah Selatan yang kondisi iklim semi kering. Keberhasilan pembangunan embung tidak hanya ditentukan oleh kapasitas tampung, tetapi juga stabilitas lereng tubuh tanggul yang mempengaruhi keselamatan dan keberhasilan fungsi embung. Penelitian ini fokus menganalisis stabilitas lereng menggunakan perangkat lunak GeoStudio 2012 dengan metode Modified Morgenstern. Analisis dilakukan pada empat kondisi operasi: saat kosong, muka air normal, muka air banjir, dan rapid drawdown. Parameter geoteknik seperti kohesi, sudut geser dalam, dan permeabilitas tanah dimasukan dalam simulasi. Hasil menunjukan bahwa nilai Safety Factor (SF) pada seluruh kondisi jauh di atas batas minimum yang disyaratkan (SF > 1.2 – 1.5), dengan nilai tertinggi 43.525 dan terendah 10.122. Temuan ini menegaskan bahwa lereng embung berada dalam kondisi sangat stabil. Dengan demikian Embung Bena secara teknis memenuhi kriteria keamanan lereng dan siap menunjang pengelolaan air secara aman dan berkelanjutanThe Bena Reservoir was designed as a water supply solution in Bena Village, South Central Timor District, which has semi-arid climatic conditions. The success of embankment construction is not only determined by the storage capacity, but also the slope stability of the embankment body which affects the safety and successful functioning of the embankment. This research focuses on analyzing slope stability using GeoStudio 2012 software and the Modified Morgenstern method. The analysis was conducted under four operating conditions: empty, normal water level, flood water level, and rapid drawdown. Geotechnical parameters such as cohesion, inner shear angle, and soil permeability were included in the simulation. Results showed that the Safety Factor (SF) values under all conditions were well above the minimum required (SF > 1.2 - 1.5), with the highest value being 43.525 and the lowest being 10.122. This finding confirms that the embankment slopes are in a very stable condition. Therefore, The Bena Reservoir technically meets the slope safety criteria and is ready to support safe and sustainable water management