Bond-slip model of anchor-soil interface and analysis of bearing capacity of anchor in frozen soil

Abstract

It has been recognized that temperature and moisture have obvious influence on the bonding characteristics of anchor-frozen soil interface. Following the principle and method used to explore the interface performance of microelement anchor-soil, this research starts by performing the pullout tests of anchor-soil under different temperature and moisture content conditions. Then, we analyze the characteristics of interface bond stress-displacement and compare the effects of temperature and moisture content on interface mechanical properties. The test results show that the failure mode of anchor changes slightly when soil temperature and moisture content vary, wherein the shear failure which shows brittle characteristics at the anchor-frozen soil interface is dominant. Additionally, we have found that the effect of temperature on the peak bond stress is more significant than moisture. Under different soil temperatures and moisture content, the shape of bond stress-displacement curve of anchor-frozen soil interface is similar. Furthermore, the bond stress-displacement relationship of anchor-frozen soil interface can be fitted by a composite function which is composed of exponential and ideal elastic-plastic model function. Thus, this research recommends to propose a bond-slip model of anchor-frozen soil interface considering temperature effect. Combined with the load transfer method, the force and deformation equation of anchor in frozen soil is derived. Through example analysis, it is discovered that the pullout bearing capacity of anchor increases with the decrease of soil temperature. Moreover, the initial shear stiffness of anchor-soil interface is positively related to the bearing capacity of anchor. At the end, the influence of interfacial residual strength on the bearing capacity of anchor in the later stage of pullout is superior to that in the earlier stage.