Abstract：The anchorage technology of bamboo bolt is an important means to deal with the stability problem of large-scale earthen sites caused by longitudinal crack. However, the force transfer mechanism of such anchoring system is still unclear, which has become the bottleneck restricting its scientific and large-scale application. The mechanical behavior of the bamboo bolt anchorage interface is studied through in-situ pull-out test in Gao Chang Ruins. The main control interface causing the slip failure and the critical anchorage length range of anchorage system are clarified. By comparing the load-displacement relationship, stress, strain and slip distribution obtained from the test, the complete de-bonding phenomenon is identified when the relative slip of anchorage segment interface exceeds 22.56mm. Then the complete de-bonding phenomenon is characterized by the non shear stress section after the friction section, and a modified tri-linear bond-slip model suitable for this type of anchorage interface is established. On this basis, the simulation method of mechanical behavior of anchorage interface based on nonlinear spring element in ANSYS is proposed, and the force transfer mechanism of anchorage system is studied systematically. Finally, the reliability of the simulation method proposed is verified by comparing with the experimental results. The results show that the slip failure of the bolt / anchoring agent interface is the main reason for the failure of the anchorage system. The stress evolution process of the interface segment can be divided into four stages: elasticity, softening, friction and complete de-bonding; With the increase of pull-out load, the high stress zone of the anchorage interface gradually transfers from the loading end to the anchorage end; After the interface enters the stage of complete de-bonding, the shear stress tends to zero, and there are critical values for the ultimate anchoring force and effective anchoring length; The shear stress transferred from the 1st to the 2nd anchoring interface is very limited, and the sites soil stress is relatively low. The results of the study can provide a reference for the optimal design of anchorage of earthen sites based on the principle of "safety first, minimum intervention".
2021, Vol. 42 
