Analisis Potensi Likuifaksi dengan Metode Deterministik di Wilayah Surabaya

Abstract

Surabaya has an earthquake potential reach to 6.5 Mw. Moreover, on average, Surabaya area is a lowland which is alluvial deposits. Thus, it is required to perform potential liquefaction. Liquefaction potential analysis was performed by taking the soil data from the center of Surabaya. The initial of liquefaction potential analysis was conducted by considering soil gradation, relative density (DR), fine content (FC), degree of saturation (SR) dan SPT number. However, the advanced analysis was undertaken by utilizing Youd and Idriss 2001 dan metode Idriss 2008. The results of initial of liquefaction potential analysis show that the soil has potential to be liquefied at the depth 1-7m, however at the depth 22m the soil is not liquefied. Furthermore, the results of advanced analysis and conclusions of the analysis show that the soil has a liquefied potential at the depth 17 m from the surface

ABSTRAK

Kota Surabaya memiliki potensi gempa yang terjadi bisa mencapai 6.5 M_w. Selain itu, Wilayah kota Surabaya merupakan daerah yang rata-rata dataran rendah, yang berkisar 80% merupakan endapan alluvial. Sehingga perlu dilakukan analisis potensi likuifaksi. Analisis potensi likuifaksi hanya dilakukan pada data tanah wilayah Surabaya Pusat. Analisis awal potensi likuifaksi dilakukan berdasarkan aspek gradasi tanah, relative density (DR), fine content (FC), derajat kejenuhan (SR), dan jumlah pukulan SPT. Sedangkan analisis lanjutan dengan menghitung Cyclic Shear Ratio (CSR), Cyclic Resistance Ratio (CRR), dan Factor of safety (FS) dengan menggunakan metode Youd dan Idriss 2001 dan metode Idriss 2008. Berdasarkan analisis awal, pada kedalaman 1-7 m masih ada potensi likuifaksi, sedangkan tidak ada lagi potensi likuifaksi pada kedalaman lebih dari 22 m. Berdasarkan analisis lanjutan dan kesimpulan analisis, hampir semua kedalaman memiliki potensi likuifaksi hingga kedalaman 17m.

Kata kunci : Likuifaksi; gempa; analisis potensi likuifaksi