Shaking table test on the effect of NPR anchor cable on slope reinforcement under earthquake

In order to study the energy absorption characteristics and dynamic response law of constant resistance large deformation (NPR) anchor cable under earthquake， and summarize the general law of unsupported slope failure under earthquake， the shaking table comparison test of unsupported slope and NPR anchor cable supported slope un⁃ der earthquake is carried out by using shaking table. Under the same working conditions， the improvement in deforma⁃ tion and damage of slopes supported by the NPR anchor cables and the fragmentation of rock⁃soil mass are obvious， compared with unsupported slopes. And the final damage degree of the NPR anchor cable supported slope is also much lower than that of the unsupported slope. It indicates that the NPR anchor rope has a good energy absorption property under the action of the earthquake， which can strengthen the integrity of the slope by absorbing the energy re⁃ leased by the earthquake， so as to reduce the degree of damage to the slope and provide effective support for the slope. By analyzing the axial force change of the NPR anchor cable in the whole test process， it is found that under the re⁃ peated actions of seismic inertia force， the axial force declines due to the fatigue effect of the constant⁃resistance struc⁃ ture within the anchor cables. With a continuous increase in the intensity of the vibration load applied， the axial force has no obvious change after decreasing to a certain value. It can be considered that the anchorage characteristics of the NPR anchor cable always exist under the action of earthquake， and it can still provide an effective support for the slope. After analyzing the variation trends of PGA amplification factors of each measuring point on slopes sup⁃ ported by the NPR anchor cables and on unsupported slopes under the same working conditions， it is found that when used in slope⁃supporting projects， the NPR anchor cables can effectively restrict slope deformation. Based on the ex⁃ perimental phenomena and dynamic response analysis， the decaying process of unsupported slopes under earthquake actions is divided into three stages: tension crack generation and slope top loosening stage， crack continuous develop⁃ ment stage， and sliding surface through slope collapse stage.