Study On Drainage Effect And Retaining Reinforcement Effect Of Water-rich Slope With Bedrock

With the rapid development of economy in western China and increase of mountain construction projects,the stability of slope with bedrock has become a hot issue.After the Wenchuan earthquake,more than a thousand aftershocks occurred in the earthquake-stricken area with abundant rainfall,which will adversely affect the slope stability,so it is very necessary to study the drainage effect and reinforce measures of slope with bedrock.In this paper,model tests are used to study the influence of rainfall intensity,soil types and drainage devices on the drainage effect of water-rich slope with bedrock.In order to ensure the slope with bedrock after drainage can resist seismic load,the retaining structures are arranged.The effects of different types and locations of retaining structures on the slope with bedrock after drainage under earthquake are studied.The failure process,failure mode,critical seismic load of failure and dynamic response of each group are analyzed.The main conclusions are as follows:1.The influence of different drainage devices on the drainage effect of water-rich slope with bedrock is studied by using a new type of self-made ventilation-drainage device.The drainage effect is shown in the following order: Laval pipe with ventilation,ordinary drainage pipe with ventilation,no drainage pipe and ventilation,ordinary drainage pipe without ventilation.It is found that the drainage effect will be reduced when ordinary drainage pipes are arranged,and the ventilator will be more contributed to drainage,and the self-made new drainage device can play the role of drainage effectively.2.There are some differences in the failure modes of slopes with bedrock under various retaining structures.Under earthquake,the failure mode of the slope without retaining structure is overall slip failure;that with anti-slide pile and frame anchor is local shear slip failure;and that with arch plate is collapsing failure on the slope shoulder.3.The acceleration amplification factor of each measuring point of the slope with bedrock without any retaining structure rises with the increase of seismic loads.However,after setting the retaining structure,that with retaining structures shows the law of "first increasing and then decreasing" with the increase of seismic loads.4.The acceleration amplification factor of the slope with bedrock without any support and with anti-slide pile at 1/3 H or 2/3 H has obvious "elevation effect" under earthquake,that is,the acceleration amplification factor rises with the increase of elevation.However,the maximum of acceleration magnification factor is located on the top and the minimum is situated on the middle and lower part when the slope with bedrock is arranged with arched plate and anti-slide pile together.5.Through the comparison of different working conditions under the critical seismic load of slope failure,the corresponding seismic load at the beginning of deformation and the corresponding seismic load when the slip surface develop through the whole body,as well as the results of dynamic response analysis,the relationship of seismic effect among three kinds of retaining structures is obtained: arch plate > frame anchor > anti-slide pile.Thus,the arch plate is more beneficial to improve the stability of water-rich slope with bedrock after drainage.