[Unpad.ac.id, 15/01/2015] Goa Seropan in karst area of Gunung Kidul Yogyakarta will be utilized to build underground weir for micro hydro power plant. This cave has an underground river with a water discharge of 600-800 liters per second during dry season that is able to power the plant.
during his presentation at Open Session of Doctoral Promotion Geological Engineering program at Meeting Room of Graduate Campus Unpad, Jln. Dipati Ukur No. 35, Bandung, Friday (15/01). (Photo by Arief Maulana) *
“Analysis of limestone quality in the Goa Seropan region is very important, with adjusted model of the rock mass classification, ” Ir. Bani Nugroho, MT explained during his presentation at Open Session of Doctoral Promotion Geological Engineering program at Meeting Room of Graduate Campus Unpad, Jln. Dipati Ukur No. 35, Bandung.
The Open session was led by Prof. Dr. Ir. Mahfud Arifin, M.S. and Dr. Ir. Vijaya Isniawardhani, M.T as secretary. The dissertation promoter team were Dr. Ir. Emi Sukiyah, M.T., Dr. Ir. Nana Sulaksana, MSP., and Prof. Dr. Ir. Eng. Edi Prasetyo Utomo. The Expert Opponent team were Prof. (EM) Dr. Ir. Ajat Sudrajat, M.Sc., Dr. Ir. Ildrem Syafri, DEA., and Dr. Ir. M. Burhannudinnur, M.Sc., with Prof. Dr. Ir. Hendarmawan, M.Sc as Professor representation. During the session Minister of Public Works and Public Housing, Ir. M. Basuki Hadimuljono, PhD was present as one of Expert Opponent team members.
Bani, who is also the head of Trisakti University Academic Administration Bureau, said that since the planned construction of an underground weir for micro hydro power plant in Goa Seropan is located in area of carbonate rocks, accurate analysis to measure the quality of the rock is very important.
“Inaccuracy of data for analysis of rock mass can cause loss of good material, funding, and the human lives,” he explained.
He also performed quality test of the rock using geomechanics classification or slightly modified rock mass classification. This was based on characteristics of karst region that has different physicality with other rocks; the use of rock mass classification in karst areas needs adjustment or modification.
Modifications done by Bani involved modification in weighted limestone rock mass in karst area. According to him, mass of limestone though dense and relatively hard, is not always massive. This causes limestone in this area to have many chamber and may even develop into a cave.
“Application of geomechanics classification in limestone should be modified, adapted to physical condition of the rock,” said Bani.
Classification models in geomechanics in limestone karst areas produce 2 Klas of quality engineering rock mass, which are Klas A that is comparable Klas III, meaning medium, and Klas B comparable to Klas IV, which means unacceptable.
Thus, classification of geometry model that he developed is relatively more relevant and simpler. “It could be used for similar research for limestone in other karst regions,” concluded Bani.
During the open session, the dissertation entitled ” Geomechanics Classification Models of Limestone Fractured Karst Cave in Goa Serpan, Gunung Kidul, Yogyakarta”, Bani obtained A “Very Satisfactory” with a grade point index value of 4.00. *
Reported by Arief Maulana / eh
