ANALISIS POTENSI LIKUIFAKSI PADA WILAYAH CEKUNGAN BANDUNG DENGAN MENGGUNAKAN METODE UJI PENETRASI KONUS

Iswanti Widiya Ambarwati; Selly Feranie; Adrin Tohari

doi:10.14203/risetgeotam2020.v30.1038

ANALISIS POTENSI LIKUIFAKSI PADA WILAYAH CEKUNGAN BANDUNG DENGAN MENGGUNAKAN METODE UJI PENETRASI KONUS

Iswanti Widiya Ambarwati, Selly Feranie, Adrin Tohari

Abstract

Secara geologi, wilayah Cekungan Bandung tersusun atas lapisan endapan danau purba yang rentan terhadap risiko gempa bumi. Dengan demikian, pengetahuan mengenai potensi likuifaksi di wilayah ini sangat diperlukan untuk mengurangi risiko gempa bumi. Makalah ini menyajikan hasil evaluasi potensi likuifaksi dan penurunan tanah akibat likuifaksi dengan menggunakan metode uji penetrasi konus (CPT) dengan mempertimbangkan gempa bumi dari zona Sesar Lembang (Mw 6,5) dan zona subduksi selatan Jawa (Mw 7,0). Berdasarkan skenario gempa bumi tersebut, penurunan tanah total sangat bervariasi disebabkan oleh perbedaan ketebalan lapisan pasir lanauan di setiap lokasi. Mempertimbangkan perbedaan percepatan tanah puncak, penurunan tanah total akibat gempa bumi dari zona Sesar Lembang akan lebih tinggi dibandingkan dengan penurunan tanah total akibat gempa bumi megathrust di selatan Jawa.

ABSTRACT - Liquefaction potential analysis in Bandung Basin area using cone penetration test method

Bandung Basin region is geologically composed of ancient lake sediments that are susceptible to earthquake risk. Therefore, knowledge of the potential for liquefaction in this region is needed to reduce the risk of earthquakes. This paper presents the results of the evaluation of the potential for liquefaction and ground settlement due to liquefaction using the CPT method by considering earthquakes from the Lembang Fault zone (Mw 6.5) and the southern Java subduction zone (Mw 7.0). Based on the earthquake scenario, the CPT locations will have a different liquefaction potential and total ground settlement due to differences in the thickness of the silty sand layer at each location. In an account of the difference in peak ground acceleration, the total ground settlement due to earthquakes from the Lembang Fault zone will be higher than that caused by the megathrust in southern Java.

Keywords

Cekungan Bandung, gempa bumi, likuifaksi, uji penetrasi konus, rasio tegangan siklik, rasio hambatan siklik, percepatan tanah puncak

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DOI: http://dx.doi.org/10.14203/risetgeotam2020.v30.1038