ANALYTICAL METHOD OF INTERFACIAL STRESS TRANSFER AND BEARING CAPACITY OF PRESSURE-TYPE ANCHORAGE SYSTEM AT EARTHEN SITE WITH CRACK SEALED BY GROUTING

In the anchorage engineering of earthen site, the pressure-type anchor compared with full-range grouted tension-type anchor possesses better bearing capacity and corrosion resistance. However, the application and development of pressure-type anchor in practical anchorage engineering of earthen site are seriously restricted, because the stress transmission mechanism of this type of anchorage system is not clear. Anchorage section in stable soil of earthen site is divided into two parts including elastic compression section and bond-slip section. The mechanical model of elastic compression section is simplified based on linear spring, while the mechanical model of bond-slip section is simplified based on hardened constituent of bond-slip at grout-soil interface. The whole process of bond-slip at the interface under the reinforcement model, which can be divided into elastic stage, elastic-hardened stage and hardened stage, was analyzed. The displacement of pressure plate, strain of grout, distribution of shear stress of grout-soil interface at each stage are derived, while the analytical solution of ultimate pull-out capacity of pressure-type anchor is given. The results show that the values which were calculated with theory of this paper of the load-displacement curve before peak load are in line with the values which were obtained from experiment. The influences of the ratio of elastic compression section is mainly reflected in elastic-hardened stage. From the parametric analysis, anchorage length is linearly related to ultimate bearing capacity, with the neglect of elastic compression section. The elastic modulus of grout mainly has influence on the stress transmission progress at interface, and has a limited impact on bearing capacity. Compared with the elastic modulus of grout, the peak value of shear stress of bond-slip model has a much greater influence on bearing capacity. This analytical method has good applicability to the analysis of the stress transmission process of pressure-type anchor used in earthen site.