The Dynamic Behavior Of Rock Slope Reinforced By Frame Anchor System And Frame Anchor Combined With Anti-slide Pile

The post-earthquake investigation results of Wenchuan earthquake and Lushan earthquake showed that frame anchor cables,as well as the combined structure of frame anchor cables and slide-resistance piles,manifested a well aseismic performance.However,the aseismic mechanisms of frame anchor cables hadn't been recognized sufficiently,which restricts its application in high intensity earthquake zone.The doctoral thesis relied on the support from science and technology program of the ministry of transportation“The research on key techniques of disaster reduction of highway construction in high altitude and intensity earthquake areas within Tibetan areas of Sichuan Province”.Based on support from above project,dynamic response characteristics of rock slope with weak interlayer reinforced by frame anchor cables,as well as acceleration amplification in weak interlayer and dynamic response of anchor cables were studied,and then aseismic design approach for frame anchor cable was proposed accordingly.In addition,a shaking table test of slope reinforced by the combined structure of frame anchor cables and slide-resistance piles was conducted.The test figured out mechanical mechanisms and aseismic performances of frame anchor cables and anti-slide piles,which acted as initiative protective structure and passive retaining structure respectively.Moreover,an aseismic divisional design method for the combination of frame anchor cables and slide-resistance piles was proposed.The main achievements and conclusions obtained in this article were showed as follows:(1)Characteristics of seismic response of slope reinforced by frame anchor systemFirst,the whole process of shaking table test of rock slope with weak interlayer reinforced by frame anchor cables was introduced in detail.Then,based on the test results,the deformation characteristics and its differences among bedrock,slide mass and frame beam,the peak value and residual value of anchor axial force,acceleration response of potential slide mass and weak interlayer were investigated.After that,a damage identification method had been proposed by utilizing the variation characteristic of acceleration spectrum.Meanwhile,the macroscopical deformation development processes of slope during earthquake were observed by using video cameras.Based on above studies,the seismic destruction mechanisms of rock slope with weak interlayer reinforced by frame anchor system were revealed.(2)The aseismic design method of slope reinforced by frame anchor systemThe dynamic response of axial force of anchor cables during the earthquake can be divided into elastic and plastic response phase,and therefore can be calculated by using lumped mass method of multi-degree of freedom system and block theory respectively.Afterwards,based on energy theory,an approach for evaluating seismic stability of slope reinforced by frame anchor cables had been proposed,whose failure pattern was linear type or logarithmic spiral type.Finally,the shaking table test results showed that it was basic conformity with the calculated results.(3)Seismic response characteristics of slope reinforced by combination structure of frame anchor system and anti-slide pileBased on the geological model generalized from prototype slope,a large scale shaking table test of slope reinforced by combination structure of frame anchor system and anti-slide pile had been carried out.The axial force in the anchor cable,the earth pressure acting on the pile,the acceleration in the slope and the deformation of the frame-beam were measured during test.After analysing the experimental data,the aseismic zone design concept of anchor cable was put forward,and the cooperative working mechanism between anti-slide pile and anchor cable during earthquake excitation was discussed.Moreover,based on the theory of Hilbert marginal spectrum,the energy varying pattern of seismic wave propagation in reinforced slope was studied,which can be used to identify the development and changing features of the damage location in the slope and evaluate the reinforcement effect of slope.(4)The aseismic design method of slope reinforced by combination structure of frame anchor cable and anti-slide pileBased on the results of shaking table test,an aseismic design method of slope reinforced by combination structure of frame anchor cable and anti-slide pile was proposed.Particularly,the seismic zone design of the anchor cable was put forward,which considered the acceleration amplification effect and the coordi-nation between the anti-slip pile and the slope deformation.In addition,the partition design process of combination structure of frame anchor cable and anti-slide pile was introduced,by using a specific engineering example.The results can provide references for the design of anchor cable frame beam and anti-slide pile supporting structure in earthquake zone.