Analysis On The Old Landslide Revival Mechanism And Stability By The Excavation Of Anti-sliding Segment

A site is located in the front zone of an ancient landslide on the left bank of Yan’anNanchuan River.For restoring the revolutionary site and displaying the historical relics ofrevolution period,the Yan’an government dicided to build a memorial on the basis of theoriginal site.But the landslide occurred local formation in the course of the foundation pitengineering excavation.In this background,we carried the exploration and governance designon it.On the basis of the exploration data,selecting the dynamic excavation process ofanti-sliding segment as the research object,using MIDAS/GTS numerical simulation softwarefor tools,then researching the stability and the mechanism of ancient landslide resurrectioncaused by the foundation excavation.The main research contents in the article are as follows:(1) Through the meatures such as field inverstigation,engineering geological surveyingand mapping,geological prospecting,find out the development features of the ancientlandslide,confirming the landslide boundary and sliding surface location,revealing theengineering geological features,and analyzing the reasons and influencing factors of theancient landslide formation.(2) According to the slope deformation and fracture development features in the processof the memorial foundation pit excavation,analyzing the process of foundation pit excavationeffect on the ancient landslide stability,confirming the ancient landslide deformation level andstability.(3) Establishing the dynamic excavation process models,selecting the relevantparameters,simulating the dynamic excavation process of anti-sliding segment by using finiteelement simulation software(MIDAS),analyzing the change of stress,strain and displacementin the slope under the different excavation depth,then analyzing the instability mechanism ofancient landslide caused by anti-sliding segment excavation.(4) On the basis of finite element simulation and change of the sliding surface, the limitequilibrium method is adopted to evaluate the landslide stability in different excavationdepth,and compared with the actual engineering conditions to prove the correctness ofsimulation results and guide the engineering excavation.