After heavy rainfall at Kangchon-Ri in Korea on 27 July in 1996, an excavated and reinforced slope for condominium construction site was failed. To figure out the cause of the slope failure and to plan remedial works, investigation of rainfall, surface and subsurface geological surveys and monitoring of the slope behavior were carried out. According to this investigation the remedial designs and works were performed. This paper describes the cause of the slope failure, the design and construction of remedial works and the monitoring of the slope behavior after the remedial works.
The wet season from June through August in Korea is characterized by heavy rainfall. Mt. Kumbong is located at Kangchon-Ri, Choonsung-Gun, Kangwon Province in Korea. An approximately 80m high rock slope in the mountain has been excavated for condominium construction and reinforced with prestressed anchors. There was heavy rainfall in this area after the completion of excavation and reinforcement. Progressive failure occurred in the prestressed anchors with about 30% of the installed anchors broken. Tension cracks and main scarps occurred 60m behind the crest and the former occurred within the excavated slope. A series of investigations to assess the cause of the slope failure such as relationship between rainfall and slope failure, geological survey of surface and subsurface and monitoring of the slope behavior, was carried out. According to the investigation, remedial design and remedial works including instrumentation were performed. This paper describes briefly the investigation, remedial design, remedial works and monitoring results after remedial works.
Slope failure started from the breakage of anchors. The breakage of the anchors began at the left, center, and right parts of the slope and 30% of the total 284 anchors were broken.