摘要:
为研究大型工程扰动区滑坡的活动强度，以引渭渠水利工程穿越的蔡家坡斜坡带为例，概括了滑坡活动强度的评价方法，在地质调查与勘察、收集滑坡变形历史资料、大比例尺地形测绘及易滑地层力学试验的基础上，运用地貌过程分析、动态数值模拟2种计算方法，探讨研究蔡家坡段各斜坡单元可能的变形形式与强度，评估了新滑坡单体的滑动速度与距离。结果表明，北坡斜坡带受工程扰动后，古滑坡体受工程扰动最为敏感，老、新滑坡体次之。南社头古滑坡复活是工程竣工后的极端滑坡事件，陕棉九厂、蔡家坡滑坡的蠕变变形加速受到引渭渠渗漏地下水交换增快的影响；蔡家坡段高活动区集中于陕棉九厂老滑坡、蔡家坡新滑坡、农副公司老滑坡前缘，而大型滑坡体周缘的地貌陡坎为中活动区，受降雨诱发的浅层崩塌、泥流的影响；蔡家坡新滑坡坡面变形活动由后缘向坡脚传递，后缘下降，前缘隆起。蠕变过程中，X方向速度达到的最大值约1.0m/s，Y方向速度达到的最大值约1.5 m/s。块体滑动过程中，滑动最大距离约130m。其中，X方向速度最大约4.5m/s，Y方向速度最大约4.0m/s。
Abstract:
For the purpose of studing the activity intensity of landslides in the disturbed area of large projects, the authors summarized the evaluation methods for the activity intensity of landslides with the slope zone in Caijiapo that the Weihe River diversion hydro-project passes through as an example, and then studied the possible deformation pattern and intensity of each slope unit along Caijiapo section and evaluated the sliding speed and distance of new single landslide mass by using two calculation methods, namely geomorphological process analysis and dynamic value simulation. The study was based on geological survey and prospecting, collection of historical data on landslide deformation, large-scale topographic survey and mechanical test on the slippery strata. Some conclusions have been reached: ①The ancient landslide mass is most sensitive to engineering disturbance, followed by landslide masses after the disturbance of the northern slope zone by the project. The renewal of ancient landslides in Nanshetou becomes an extreme landslide event after the completion of the project, and the acceleration of exchange of leaked ground water from Weihe River diversion has affected the boosting of the creep deformation of landslides in No. 9 Shaanxi Textile Factory and Caijiapo; ②The high activity areas in Caijiapo section are concentrated in the old landslide in No. 9 Shaanxi Textile Factory, new landslide in Caijiapo and front edge of old landslide in agricultural products company, while the geomorphic scarps on the periphery of large sliding masses form the middle activity areas which will be influenced by shallow failure and soil flow induced by rainfall; ③The slope deformation activity of new landslide in Caijiapo is transmitted from the rear edge to the slope toe, causing the subsidence of the rear edge and the uplifting of the front edge. In the process of creeping, the speed in X direction reaches the maximum of about 1.0m/s, while that in Y direction reaches the maximum of about 1.5m/s. In the sliding process of masses, the maximum sliding distance is 130m approximately; therefore, the maximum speed in X direction is about 4.5m/s, while that in Y direction is about 4.0m/s.
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