考虑前缘桩锚支挡作用的滑坡变形预警指标研究

在考虑坡体前缘抗滑桩锚索对坡体下滑的阻挡作用的基础上,提出滑坡变形总量与变形速率预警指标。以四川岷江电化有限公司厂区西侧滑坡为例,利用强度折减法,通过FLAC数值模拟得到滑坡失稳破坏时的坡向位移,之后减去锚索所能承受的最大变形量,拟定滑坡坡表变形总量预警阈值,并且根据前人统计研究得到的一般性滑坡变形速率与滑坡实际监测资料分析,拟定滑坡坡表变形速率预警阈值。计算结果表明:监测点JC01坡表变形总量蓝色、黄色、橙色与红色预警阈值分别为0.00 cm、38.84 cm、58.26 cm、77.68 cm;监测点JC02坡表变形总量蓝色、黄色、橙色与红色预警阈值分别为0.00 cm、63.00 cm、94.51 cm、126.01 cm;监测点JC03坡表变形总量蓝色、黄色、橙色与红色预警阈值分别为0.00 cm、46.84 cm、70.26 cm、93.68 cm;滑坡的坡表变形速率蓝色、黄色、橙色与红色预警阈值分别为0.00 mm/d、0.11 mm/d、1.61 mm/d、10.00 mm/d。研究结果为四川岷江电化有限公司厂区西侧滑坡预警阈值的拟定提供了相关参考与依据。

Leading edge pile anchor supporting and retaining effect-considered study on early warning index of landslide deformation

Based on the consideration of the blocking effect of the anti-slide pile anchor cable at the slope leading edge on the down-slip of slope body，the early warning indexes for the total deformation and deformation rate of landslide are put forward herein． By taking the landslide occurred at the west side of the factory area of Sichuan Minjiang Electrochemical Co．，Ltd． as the study case，the slope-aspect displacement during the unstable failure of the landslide is obtained through the FLAC numerical simulation by means of the strength reduction method，and then the early warning threshold of the total deformation of the slope surface of the landslide is worked out by subtracting the maximum deformation that can be borne by the anchor cable，while the early warning threshold of the deformation rate of the slope surface of the landslide is worked out in accordance with the analyses made on the conventional landslide deformation rate and the actual monitoring data of landslide obtained by the previous relevant statistical studies． The calculation results show that the blue，yellow，orange and red early warning thresholds of the total slope surface deformation at the monitoring point—JC01 are 0. 00 cm，38. 84 cm，58. 26 cm and 77. 68 cm respectively and the blue，yellow， orange and red early warning thresholds of the total slope surface deformation at the monitoring point—JC02 are 0. 00 cm，63. 00 cm，94. 51 cm，126. 01 cm respectively，while the blue，yellow，orange and red early warning thresholds of the total slope surface deformation at the monitoring point—JC03 are 0. 00 cm，46. 84 cm，70. 26 cm，93. 68 cm respectively． Meanwhile，the blue，yellow，orange and red early warning thresholds of the deformation rate of the slope surface of the landslide are 0. 00 mm/ d，0. 11 mm/ d，1. 61 mm/ d，10. 00 mm/ d respectively as well． The study results provide the relevant referential basis for working out the early warning thresholds for the landslide occurred at the west side of the factory area of Sichuan Minjiang Electrochemical Co．，Ltd．