PEMODELAN PERILAKU RAYAPAN TANAH (CREEP) STUDI KASUS LERENG KALIBAWANG

Didik Junaidi, Dr. Ir. ahmad Rifa'i, M.T.

2011 | Tesis | S2 Teknik Sipil

Creep atau rayapan sebagai bagian menarik dari longsor, selama ini diasumsikan terjadi pada lereng di sebelah selatan Tawang Bawong Saluran Irigasi Kalibawang km 15.9 sejak tahun 1980-an. Setelah bangunan talang digeser, saat ini terlihat adanya kerusakan pada bagian sambungan. Berbagai penelitian telah dilakukan dengan menggunakan model elasto-plastic sehingga deformasi yang diperoleh bukan fungsi waktu. Tujuan penelitian ini adalah untuk mempelajari perilaku rayapan pada lereng menggunakan model numerik

Creep or soil movement as the interesting part of landslide, already happened since 1980's at south side of Talang Bawong Kalibawang Irrigation Channel km 15.9. Various researches have been conducted by using elasto-plastic model which can not accommodate the time dependent behaviour. The objective of this research is to study the creep behaviour using numerical model.Soil constitutive model that used are Mohr-Coulomb and soft soil creep that already available in Plaxis. Some engineering judgements are used to give good correspond to field strain data recorded. The behaviour of creeping slope is studied by concerning groundwater level, static loads, seismic and collapse condition of slope.The study result showed that creep depends on groundwater level and its fluctuation which the ground movement can reach about 0.192 mm/year at side of street. Due to the load increment, maximum creep at inspection road reach 0.08 mm/year. For one second period seismic force the slope able to creep until 37.28 mm/year although reduction form 0.395 mm/year up to 0.547 mm/year in three years after. In assumption failure will be happened after 1.05 m up to 1.56 m displacement, the slope failure can occurred about 6 month untill 12 month later. Towards failure in progress the creep increased up to 564.6 mm/year up to 2549.8 mm/year.

Kata Kunci : Lereng, Creep, simulasi numeris, model konstitutif tanah, muka air tanah, dan gempa