Study On Timeliness Of Excavation Support And Sensitivity Of Anchorage Elements For Rock Slope

In recent years,with the needs of social development and construction,human activities for the transformation of nature have intensified.large number of high-steep engineering slopes have appeared in the construction of water conservancy projects,road projects and mining projects.Especially for the slope of hydraulic engineering,the engineering geological conditions are complex and changeable.Even if the research on slope stability has made great progress,the slope problem of complex working conditions cannot be completely solved.Therefore,it is still of great significance to strengthen the study of slope stability.In this paper,through the excavation and support process of the slope of hydraulic engineering and the stability of the slope to study the stability of the slope during the excavation process,the mechanism of the displacement field and the instability mechanism of the slope and the stability of the slope are different.The changing characteristics under the anchoring factor hope to provide certain reference value for the subsequent engineering construction.The specific research contents and results of this paper are as follows:(1)Based on the slope data of cable crane platform on the left bank of dam,the finite element model of slope is established.Using ANSYS to carry out numerical simulation calculation of excavation without support,the displacement of slope monitoring points and the safety factor of slope stability under the condition without support are analyzed.It is found that during the excavation process,the rock mass near the excavation is disturbed,and the displacement of the characteristic point is a process of accumulation along with the excavation.The safety factor of the slope shows a gradually decreasing process,and Faults and broken veins have an important impact on the stability of slopes,and need to be paid attention to in engineering support.(2)Considering three different anchorage depths,the displacement and safety factor of slope under different supporting time are calculated respectively,and the time-effect of slope anchorage support is analyzed through its changing law.The results show that the time-effectiveness of slope anchorage support is obvious,the displacement of timely support under the same conditions is smaller than that under lagging support,and the displacement under support condition is obviously smaller than that under non-support condition.The variation law of slope stability safety factor is consistent with that of displacement.(3)Through the analysis of the stability of slopes with different anchoring factors,it can be known that the anchoring slope has the optimal supporting length,and the safety and stability of the slope are an increasing process before the supporting reaches the optimal length.After the optimal working condition is reached,the stability of the slope is abrupt,which is a process in which the plastic penetration zone is pre-positioned and the safety stability is suddenly reduced and stabilized.The slope of the bolt support inclination is within a certain range,and the slope is larger.The better the stability,but the greater the anchoring inclination,the better the overall stability of the slope after the support length reaches the effective support length;the stability of the supporting slope with the small anchor spacing is excellent under the same conditions.Support slopes with a large spacing.