Shear Effects On The Anchorage Interfaces Of A Rock Slope Containing A Weak Layer Under Seismic Action

There are a large quantity of slopes and a frequent occurrence of earthquakes in China,therefore the stability of slope under earthquake is very prominent,anchoring is extensively used in slope supporting due to its unique advantages,but so far,the research into the bolt anchorage mechanism of slopes has just started,which seriously hinders the research on the stability of anchoring slope and the popularization and application of anchoring technology,and leaves safety hidden danger to the project.The research made innovations in the modeling methods by taking a dip rock slope containing weak layers anchored by full-length bonded bolts as the research object using the shaking table test and numerical simulation analysis.On this basis,the shear effect on the bolt–grout interface and the grout–rock interface in the rock slope under seismic action were studied thoroughly and systematically,the anchor mechanism of slope under seismic action were revealed,a series of research results were obtained.Therefore,the study has important theoretical significance and engineering application value.The main innovations and research findings are shown as follows:?1?The similar materials obeying the similarity relation,with favorable fluidity,bonding properties,and appropriate solidification time were developed,the large-scale test model of a rock anchoring slope containing a weak layer by applying casting method and its seismic response testing system were constructed,and shaking table model tests were undertaken thereon.?2?The acceleration and displacement and the strain on the two anchorage interfaces of the slope model were measured by the shaking table model test,the response law and failure mechanism of the slope and the strain distribution along the anchor bolt length and its evolution under seismic action were researched.The shear effects on the anchorage interfaces under seismic action with different seismic wave types and excitation directions by conducting shaking table model tests were studied,and its relation with seismic response of slope surface were revealed.?3?The modeling method for numerical simulation was innovated and improved using the FLAC^3D,and two modeling methods for numerical simulation,that is,interface element–solid element and cable element–solid element were developed.The feasibility and consistency of the two methods were exemplified and the superiority and ranges of application of the two were pointed out.The results were mutually verified with the shaking table model test.?4?The distribution and evolution of shear stress on the two anchorage interfaces was thoroughly and systematically studied by combining shaking table model test and numerical simulation.The evolution process from deformation to debonding failure of the two anchorage interfaces under seismic action was revealed.The study found that the evolution process of the shear stress on the bolt–grout interface were divided into four stages:positive and negative cycles,rapid growth,oscillations,and debonding failure,as well as the evolution process of the shear stress on the grout–rock interface were divided into three stages:positive and negative cycles,rapid growth,and debonding failure.?5?The influences of ground-motion parameters,anchoring parameters and slope weak-layer parameters on the shear effects of two anchorage interfaces and seismic responses of slope were systematically studied through numerical simulation method,thus obtaining changes of the peak shear stresses and debonding lengths on the two interfaces,and displacement of the slope under different influencing factors.