Study On The Excavating Stability And Reinforcement Measures At A Bedding Rock Slope

As the most widely distributed type of rock slopes,layered slopes exist widely in the field of transportation construction.In the process of slope excavation,layered slopes,especially bedding slopes,have the more instability problems and harm.The stability of the bedding slope whose dominant structural surface of the bedding slope is bedding is jointly affected by a large number of joints in the rock mass,and slope failure mode is more complicated.So it is necessary to study the stability of the bedding slope during excavation.In order to study the stability of the bedding slope during the excavation process,this paper takes the newly-built 110 national highway K528+308～K528+398 section of the deep cut slope as the supporting project,By establishing a three-dimensional simulation geological model of the slope,Flac3 D software was used to simulate and calculate the dynamic response of the bedding rock slope during the excavation process,and the effect of the reinforcement measures on the slope was studied.Research work and main results as in there:(1)By simulating the excavation process of the bedding rock slope under the unsupported condition,the failure mechanism of the bedding rock slope during the excavation process is studied.The result is as follows,under the condition of unreinforced excavation on the bedding rock slope,When the excavation slope is gentle and there is no free face at the lower part,the bedding characteristics of the slope are not obvious,the deformation of the slope is mainly the rebound deformation after unloading,when the excavation surface is relatively large,the slope will slide down along the layer,and a large area of tensile stress is distributed on the excavation slope,in addition,there is an overall through shear strain increment distribution zone in the excavation slope area,the potential failure type of the slope is slip-crack failure.(2)The slope collapsed locally during construction.By simulating the excavation of the slope after the reinforcement,the stability of the slope in the actual construction process is studied and analyzed.The result is as follows,when the slope is excavated after the anchor cable frame support,there is a potential dangerous zone in the left part of the engineering slope,and there is no risk of instability of the slope as a whole,the simulation results are consistent with the collapse of the construction site.(3)The same reinforcement measure method has different effects on slopes of different structures.By simulating the excavation of the slope under different reinforcing conditions,the effect of the reinforcement measures on the slope is studied.The result is as follows,both the anchor cable frame and the anti-slide pile can restrain the layer slip during the excavation of the bedding slope,after excavation with the reinforcement of anchor cable frame,the slope deformation mainly occurs at the lower free face,the anchor cable frame has limited reinforcement effect on the lower part of the slope,after the slope is reinforced by the anchor cable frame,the lower part still has the risk of local instability,the combined reinforcement method of anchor cable frame and anti-slide pile can not only improve the overall stability of the slope,but also prevent local damage to the slope.(4)An automated monitoring system is installed on the slope to monitor the stability of the slope stably and efficiently.The monitoring results show that the slope has been in a good stable state since the end of the construction,indicating that the reinforcement measures are of good effect on the slope.