DEVELOPMENT OF SLOPE MASS STABILITY ASSESSMENT IN TROPICAL REGION AROUND JATIGEDE DAM PROJECT, SUMEDANG REGENCY, WEST JAVA, INDONESIA

• Main Authors: , NGUYEN HUYNH THONG, , Prof. Dr. Dwikorita Karnawati, M.Sc., Ph.D.
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2013
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/122674/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=62778
• Institution: Universitas Gadjah Mada

The research develops the new concept for evaluating of controlling factors on slope mass stability - SMS around the Jatigede dam project in Sumedang regency, West Java, Indonesia. The objectives of study are to provide an understanding about the relationship between behavior of SMS and its controlling factors in tropical region. Furthermore, the influence of weathering rock on SMS was also been analyzed in laboratory as well as using numerical modelings � 2D Plaxis program. The research applied a statistical analytical method on 9 items, which controlled to SMS. By calculating, 9 significant items were identified, such as slope angle, rock type, weathering, joint condition, rock quality designation - RQD condition, rock strength, rainfall, groundwater, and human activity. According to 354 observed slopes in the field, 88 slopes were the potential instability meanwhile 14 other slopes were unstable. Moreover, from the analytical result, the order of the most significant factors was slope angle, rock type, weathering, and RQD condition. A new assessment of SMS with the order of controlling factors, categories, and descriptions was also proposed to apply for any SMS assessment in the field. Weathering/alteration conditions which dominated by Smectite, Kaolinite, and Halloysite will be significant in controlling SMS when percentage area beyond 55%, because they absorbed much water easily and strongly. Besides, with the appearance of some clay types such as Smectite, alteration was also occurring in the study area. In the last step of the research, the influence of weathering condition, systematic joint, and seismic acceleration was modeled by numerical modeling - 2D Plaxis program. Thereby, when weathering zone covered on the slope surface, slope would become a potential instability or be able to fail immediately. Beside, systematic joint (joint orientation) was also a significant factor of SMS assessment. In contrast, seismic acceleration did not influence to the stability of rock slope in the study area.