Analysis Of The Stability Of The Slope Ground Motion Reinforced By Frame Prestressed Anchors

The frame prestressed anchors support structure is one of the most widely used support forms in northwest region of China,the slope engineering reinforced by it is mostly in the seismic disturbance areas.The serious deformation and even collapse of the slope caused by the earthquake will seriously threaten the safety of people’s lives and property.Therefore,it is of great practical significance to analyze the seismic stability of the slope reinforced by frame prestressed anchor s.In this paper,pseudo-static method,displacement back-analysis method and strength reduction method are used to study the seismic stability and deformation of the slope reinforced by frame prestressed anchors and the relationship between the two.Mainly completed the following scientific research works:(1)Based on the limit equilibrium theory and assuming that the potential sliding surface of the slope is arc-shaped,a ground motion stability analysis model of the slope reinforced by frame anchors considering the prestress of anchors is established.In the model,the prestress is equivalent to the distributed force along the tangent and normal direction of the slope,and the slope stability is analyzed by calculating the additional stress generated by the distributed force.On this basis,the functional relationship between the coordinates of the circle center of the potential sliding surface and the safety factor is established.With the help of the optimization algorithm toolbox in MATLAB,the possible location area of the center of the circle is dynamically searched,and the minimum safety factor of the slope is obtained.Finally,it is calculated in combination with a certain actual slope project,and compared with the finite element results.(2)Using the displacement back-analysis method,back-analyze and optimize the mechanical parameters of the slope soil,the samples of inversion analysis are obtained by uniform experimental design,and the PSO-BP neural network algorithm is used for network training,substitute the inverted soil mechanical parameters into the safety factor analytical formula and PLAXIS 3D finite element software to solve the safety factor and displacement of the slope under different peak accelerations,and establish the relationship between the two through the non-linear fitting method.Based on this,the allowable displacement values of the slope top,slope waist and slope foot under the limit state of the slope are obtained,the stability of the slope is analyzed by comparing the actual displacement of the slope and the allowable value of the displacement.(3)Combined with an example of a slope reinfo rcement project,the strength reduction method is used to reveal the shape,location and scope of the potential sliding surface of the slope reinforced by the frame prestressed anchor s under earthquake,the safety factor of the slope is calculated,at the same time,the deformation law of slope is obtained,synthesize three types of slope destabilization criteria,the slope stability is analyzed by observing the slope deformation.Finally,by changing the anchor spacing,anchor prestress,horizontal seismic peak acceleration and vertical seismic action strength,PLAXIS 3D software is used to analyze the finite element parameter analysis of the ground motion stability and deformation of the slope reinforced with frame prestressed anchors.