Di negara-negara berkembang seperti Indonesia, khususnya di kota besar seperti Jakarta, pembuatan terowongan jalan raya sudah selayaknya dipertimbangkan untuk mengatasi masalah kemacetan lalu lintas. Selain itu, kondisi geologis dan geografis Indonesia yang kaya akan mineral tambang, dan banyak memiliki kontur pegunungan, semakin mendukung pembuatan konstruksi terowongan di Indonesia di masa yang akan datang. Di sisi lain, Indonesia merupakan daerah pertemuan tiga lempeng tektonis besar (Indo-Australia, Eurasia dan Pasifik), menyebabkan Indonesia rawan terhadap bencana gempa bumi. Gempa bumi dapat menimbulkan kerusakan bangunan termasuk diantaranya konstruksi terowongan. Melihat fenomena di atas, sangat perlu dilakukan penelitian tentang pengaruh beban gempa terhadap konstruksi terowongan. Penelitian ini merupakan analisis stabilitas terowongan tambang, milik PT Aneka Tambang Tbk, yang berlokasi di Gunung Pongkor, Bogor, Jawa Barat. Analisis dilakukan dengan metode numeris menggunakan software plaxis v.8.2. Idealisasi plane strain dengan material model Mohr Coloumb digunakan dalam pemodelan numeris ini. Beban gempa diterapkan dalam bentuk Peak Ground Acceleration (PGA), dengan lima variasi nilai PGA yaitu 100, 150, 200, 250, dan 300 cm/dt2. Data gempa diambil dari United States Geological Survey (USGS) dalam format Strong Motion CD (SMC). Dalam penelitian ini, diamati perubahan nilai displacement dan tegangan akibat variasi nilai PGA. Tiga kondisi terowongan diterapkan dalam analisis ini, yaitu kondisi tanpa penyangga, dengan penyangga sesuai di lokasi penelitian, dan dengan penyangga berdasarkan analisis Q sistem. Hasil penelitian ini menunjukkan bahwa kenaikan PGA menyebabkan kenaikan deformasi dan tegangan pada terowongan. Beban gempa akan menyebabkan deformasi yang cukup besar di sekitar dinding terowongan. Sistem penyangga sesuai di lokasi penelitian sudah cukup kuat untuk mendukung beban gempa di bawah 300 cm/dt2 (0.3g). Penambahan kekuatan penyangga hanya diperlukan apabila terjadi beban gempa dengan kekuatan 300 cm/dt2 (0.3g) keatas, dan penambahan kekuatan penyangga disarankan dilakukan di sekitar dinding terowongan.

In the developing countries like Indonesia, especially in the big cities like Jakarta, tunnel constructions should be considered to solve traffic problems. Besides, geological and topographical condition in Indonesia that is rich of mine materials make tunnel construction will be developed in the future. But then, Geographical condition in Indonesia that lies in intersection of the three tectonic plates, makes Indonesia vulnerable of earthquake disaster. Earthquake will destroy every building included tunnel constructions. Based on this phenomenon, it was necessary to make research about influence of earthquake load to tunnel construction. Stability analysis of mine tunnel that belongs to P.T. Aneka Tambang Tbk., located in Pongkor Mountain, Bogor, West Java, would be done in this research. This analysis was conducted with numerical method using plaxis v.8.2 software. Plane strain idealization and Mohr Coloumn material model were used in the numerical model. Earthquake loads were applied in Peak Ground Acceleration form, with five variations of PGA that are 100, 150, 200, 250, and 300 cm/s2. Earthquake data were downloaded from United States Geological Survey (USGS) in Strong Motion CD (SMC) format. In this research, change of deformation and stress of the tunnel construction in consequence of variation of the PGA values would be observed. Three conditions of tunnels would be applied in this research namely tunnel without supporting system, tunnel with original supporting system (same as in the research location), and tunnel with Q system supporting system. The results of this research show that the increase of PGA will increase both of deformation and stress of the tunnel constructions. Earthquake load cause significant deformation in wall area of tunnel. Based on the result of numerical simulation, original supporting system (same as in the research location), is strong enough to support earthquake load that less than 300 cm/s2(0.3g). Wall area additional support is needed only when the earthquake load more or equal than 300 cm/s2(0.3g).

Kata Kunci : Terowongan,Stabilitas,Gempa bumi,Peak ground acceleration,Simulasi numeris,Displacement,Tegangan, tunnel, stability, earthquake, peak ground acceleration, numerical simulation, deformation, stress