Study On Dynamic Response Of BFRP Anchor Wire Frame System Reinforced Slope Under Earthquake Effect

BFRP(Basalt Fiber Reinforced Polymer/Plastic)anchor(cable)frame structure has a good reinforcement effect on the rock and soil slope,however,the research on the seismic performance of such reinforced slope is almost blank,and this deficiency directly or indirectly limits the promotion and application of BFRP anchor(cable)frame structure in the reinforcement of slope in high earthquake-intensity area.Based on the dynamic response of the BFRP anchor frame reinforcement slope under earthquake action,a large-scale shaking table model test and numerical simulation study are carried out,the research content involves dynamic response of BFRP cable in anchorage body,time-frequency characteristics of slope acceleration response and slope dynamic protection effect of BFRP anchor frame,the following results and conclusions were drawn:(1)Through the large-scale shaking table model test,the dynamic response of the BFRP cable in anchorage body under seismic loading is studied.Using the strain gauges attached to the anchor cable,the strain waves on different anchor cable sections and different anchoring depth anchor cables during dynamic loading are measured,and the axial force amplitude and residual deformation of the BFRP anchor cable caused by seismic action are analyzed.Through the preliminary law of the vibration energy distribution of the anchor cable obtained by wavelet packet decomposition,the transmission characteristics of the main frequency of the anchor cable along the anchorage depth are further discussed,and the damage mode of the BFRP anchor cable anchorage structure under dynamic action is revealed.(2)Based on the shaking table model test comparison of BFRP anchor frame reinforcement slope and unreinforced slope,the dynamic response of the acceleration amplification factor of typical slope slope under different seismic loading conditions is quantitatively analyzed,consider the relationship between the positive and negative acceleration peak amplification factors of the unit body,established the acceleration peak ratio(Ki)-height curve and it is revealed that the input of different acceleration peak seismic waves affects the shear stress at different heights of the slope.(3)Using wavelet packet decomposition in the field of signal processing and Response spectrum to deal with measured acceleration response in shaking table model test,by analyzing the main frequency variation of seismic waves during the superficial transfer of slopes,the limiting effect of the BFRP anchor frame on the "beat" effect of the slope is explored,The maximum response of BFRP anchored slope and unanchored slope under ground motion time history is studied combined the resonance effects of the dynamic characteristics of the unit(self-vibration period,mode shape and damping).(4)By numerical calculation method,the acceleration,displacement field and stress field response of FRP anchored slope and unsupported slope under seismic dynamic action are compared,and the slope dynamic anchoring effect analysis is carried out,it is considering that the BFRP anchoring structure can limit the displacement of the slope under the action of seismic dynamics,inhibit the formation and scale of the potential slip surface in the sliding body,and transfer the seismic load from the sliding body to the bedrock to some extent,the BFRP anchorage slope has shown good seismic performance.