Study On The Engineering Property Of Loose Zone In Rock Slope Of Open-pit

Deep rock slope of open-pit is rock excavation engineering at present. Sutdy on the engineering proterties of loose zone in rock slope of open-pit can provity point of reference for slope Stability evaluation, reinforcement and optimizational disign of slope shape. Based on the slope engineering in JinDuiCheng (JDC), the mechanical proterties of loose zone have been presented by lots of ways. Main research work and results are as fllows:(1) The distribution rules and damage modes of the joint fissure are researched based on the survey data of the deep slope in JDC open pit. It is found that most loose rock masses of the slope are stable; the wedge damage and plane damage are the two main damage modes of the possible local damage which is coOntroIIed by structural plane; and the slope with faults is damaged in the form of plane, the loose layers formed after frequent landslide possibly damaged again in the form of curved surface.(2) Results of the acoustic test show that the mean value of wave speed, static Yong's modulus and deformation modulus are relatively low in the major loose zone, while corresponding values increase with the incensement of hole-depth; Deformation rules of loose zone are analyzed through the results of deformation monitoring. Both show that, on one hand, the loose zone of upper slope is larger than that of lower slope because of the long influence of weathering, precipitation and blasting, thus steepening slope angle is possible; on the other hand, the loose zone of slope along the long side is lager than that along the short side for the deep slope which is rectangular-shaped on horizontal plane, so the circle or oval shape on the horizontal plane is appropriated for the open-pit.(3) Fast Lagrangian Analysis of Continua (FLAC3D) program is applied for numerical simulation in this thesis. It is found that the peak value of principle stress appears in the deep part of rock mass, scope and value of tensile stress increase when considering the loose effect, which results in poor slope stability. Stress distribution in the slope is influenced not only by distribution of loose zone and loose extent, but also spatial shapes of deep slope of open-pit.Through the work of the engineering and hydrology geology investigating, geologic structural planes investigating, acoustic test and deformation monitoring, and study on distribution rules of geologic structural planes, damage modes of slope, scope of loose zone, deformation rules with FLAC3D numerical simulation, the engineering proterties of loose zone is knowledged. These reseasch can provide provity point of reference for steepening slope angle, slope Stability evaluation, reinforcement and optimizational disign of slope shape.