Evaluasi Keamanan Tubuh Bendungan Grawan Berdasarkan Kondisi Hidrologi dan Geologi Terkini (Grawan Dam Safety Evaluation Based On Current Hydrological and Geotechnical Data)

Abstract

ABSTRAK: Pada studi ini dilakukan evaluasi keamanan tubuh Bendungan Grawan berdasarkan data hidrologi dan geoteknik terkini, yakni meliputi: penelusuran banjir, perhitungan rembesan menggunakan Software Geoslope dengan berbagai kondisi muka air, serta perhitungan stabilitas lereng bendungan kondisi statis dan dinamis (dengan gempa OBE dan MDE) dengan menggukanan metode Fellenius dan Bishop yang dilakukan menggunakan Software Geoslope dengan melihat Peta Gempa Indonesia 2017. Hasil analisa menunjukkan bahwa kondisi hidrologi berdasarkan penelusuran banjir pada Bendungam Grawan aman terhadap tinggi jagaan, rembesan yang terjadi pada tubuh bendungan masih aman terhadap debit ijin rembesan (1% debit inflow rata –rata), serta stabilitas lereng bendungan grawan menunjukkan hasil kondisi statis, OBE, dan MDE 100% aman terhadap faktor keamanan ijin stabilitas.

Kata Kunci: Bendungan, Hidrologi, Rembesan, Stabilitas Lereng

 

ABSTRACT: In this study, Grawan Dam safety evaluation was calculated based on current hydrological and geotechnical data, which included: flood routing, seepage calculations using Geoslope Software with various water conditions, and slope stability of the static and dynamic conditions (at OBE and MDE) calculations using Fellenius and Bishop methods using Geoslope Software by looking at 2017 Indonesian Earthquake Map. The results of the analysis show that hydrological conditions based on flood routing in Grawan Dam is safe from embankment height, the seepage that occurs in the dam body is still safe from permits discharge (1% average inflow discharge), and the slope stability of the dam shows statistical results, OBE and MDE are 100% safe from the safety factor of a stability safety permits.

Keywords: Dam, Hidrology, Seepage, Slope Stability