The Large Scale Shaking Table Test Of BFRP Anchor(Cable) In High Slope Protection Of Xiangshuihe River In High Intensity Earthquake Area

China belongs to a country prone to earthquakes.It often leads to the instability and destruction of high slopes under the action of earthquakes,which poses a great threat to people's lives and property safety.For the protection design of high slopes,the traditional steel anchor(cable)can effectively limit the deformation of the slope body when the seismic intensity is low while the steel anchor(cable)is often damaged due to its insufficient deformation capacity when the seismic intensity is high.At the same time,under the action of some corrosive chemicals in groundwater and slope,the traditional prestressed anchor bar(cable)is often aged,damaged or even destroyed,which leads to the whole instability of the anchored slope.However,the new material of basalt fiber reinforced plastics(BFRP)is used to replace the traditional reinforced anchor(cable),which can effectively solve the corrosion problem of the anchor(cable)inside the slope and has obvious anti-seismic effect.To make sure the feasibility of replacing steel anchor(cable)with BFRP anchor(cable)in the anti-seismic application of slope,the large-scale shaking table model test and numerical calculation analysis of the support structure of BFRP anchorage system and reinforcement anchorage system were carried out.The dynamic response characteristics of slope under earthquake and the mechanical deformation characteristics of its supporting structure were reproduced,and the following results and conclusions are obtained:(1)The distribution state of peak axial force curve of anchor(cable)can show the deformation stage of slope.In addition,the relationship curve between peak axial force at the end and tail of two kinds of anchor(cable)and peak input wave is almost the same.The anchor(cable)and the slope supported are in the elastic stage when the peak value of input wave is less than 0.2g,the slope is in the plastic deformation state when 0.2g-1.0g,and the slope is in the failure stage when 1.0g-1.4g.(2)In the actual slope support engineering,we should not only pay attention to the anchorage of the anchor(cable)tail,but also focus on the tensile strength of the end.For the slopes supported by BFRP anchors(cables),the anchoring strength and tensile strength of the middle-lower anchors(cables)in the slope body must be considered when designing for earthquake resistance.However,the existing "strong foot and waist" principle can be met in low-intensity areas for the seismic design of steel anchors(cables)in slope support,while the anchoring strength and tensile strength of the anchor rod(cable)at the top of the slope should also be considered for the design of anchorage system in high-intensity areas.In addition,if the BFRP anchor rod(cable)is used instead of the steel anchor rod(cable)in the seismic design of the slope,the axial force value at the end of the anchor rod(cable)can be effectively reduced,which can avoid the situation that the end of anchor(cable)is pulled out due to excessive stress.(3)The seismic waves in the first frequency band(0.1~6.26 Hz)and the second frequency band(6.26~12.51 Hz)mainly affect the BFRP anchor(cable)and steel anchor(cable),and the first frequency band(0.1~6.26 Hz)seismic waves play a leading role.In the seismic design of slope,BFRP anchor(cable)instead of steel anchor(cable)can effectively reduce the impact of the first frequency band seismic wave on the anchor(cable),so as to have a good seismic effect.(4)Compared with steel anchor(cable),BFRP anchor(cable)can effectively reduce the influence of seismic wave on slope body,and can play a certain attenuation effect on seismic wave.Thus,the acceleration amplification coefficient and response spectrum amplitude of slope decrease.(5)With the different deformation of the slope,the predominant frequency of each acceleration measured point is different.Compared with the middle and lower slopes,higher frequency seismic waves have a greater influence on the upper slopes.Further,compared with the slope supported by steel bolts(cables),BFRP bolts(cables)can improve the overall stability of the slope,especially to limit the dynamic response of the middle and lower part of the slope effect.