Study On Stability, Movement Characteristics And Countermeasures Of Unstable Rock Mass In Sambang Mountain

Collapse of unstable rock is one of the most severe globally mountainous geologicaldisasters problems. Collapse of dangerous rock has the basic characteristics ofuniversality, quickness, concealment and strong destruction. With the expanding ofhuman living space and developing of the infrastructure engineering construction, thesituation of Collapse of unstable rock is becoming worsening day by day. So it isnecessary to accurately, timely and relatively systematically study the unstable rockformation and its development process, the classification of unstable rock deformationand failure model，evaluation method of its stability，movement characteristics ofrolling rock and countermeasures of potential unstable rock. This study has highacademic value and guiding significance to the engineering practice.This paper regards unstable rock mass in the slope of southeast side of SambangMountain as the object of study in Seogwipo City in Jeju Island, Korea, and takes therange along NO.8highway from the foot of the mountain (Length about700m)as studyarea. Followings are the main achievements gotten.(1) By collecting data on the theoretical research and site investigation, we learnedthe topography and geomorphology, stratum and lithology, geological structures,hydrogeological condition, climatic characteristics and vegetation characteristic.Specific geological and environmental conditions in the research area has been acquired.The development of unstable rock formation is a continuous accumulation and thefactors affected the process is to be found to provide the basis of research informationfor subsequent research work.(2) The survey method combined the on-site investigation and3D laser scanningtechnology is used to statistical analysis distribution range, size, quantity, andmorphological characteristics of unstable rock mass in Sambang Mountain. There aresome unstable rock mass in high and steep slope, and even in the cliff, and it is toodifficult to implement the artificial investigation.so using3D laser scanner3D spatialdata of unstable rock mass can be acquired, like location, elevation, distribution rangeand constructional surface and so on. And we did statistical research on unstable rockmass in Sambang Mountain. According to the scene a lot of exploration measurementinformation, we studied on formation factors and development characteristics, andanalyzed deformation instability mode and classification of unstable rock mass inSambang Mountain.(3) The main joint surface of rock slope in Sambang Mountain is statistical analyzed.And the structural plane stereographic projection is used to evaluation of unstable rockslope stability of ZONE1, ZONE2, and ZONE3. Unstable rock mass physical andmechanical parameters, structure characteristics and boundary conditions is cleared toanalysis the influence the stability of unstable rock under the condition of rainfall byusing the discrete element analysis software UDEC. Under the action of the torrentialrain, fissure water is unceasing seepage, and increases structural surface expanding.And the stability of unstable rock mass decreases. Finally it will cause the hazards ofCollapse and falling stones.(4) Using numerical simulation software Rockfall, the collapse of rockfallmovement model is established. The numerical simulation graphs of the moving route of dangerous rock, power distribution and bounce height are drawn through settingtangential coefficient of restitution, normal restitution coefficient and dynamic frictioncoefficient, which can provide theoretic guidance for guiding the structure design ofprotection system and ensuring the prevention effects.(5) By expounding all kinds of protective system, we put forward the correspondingeconomic effective protection management advice, like rock fall roof, safety nettingSystem.