Anchoring solid-soil interface behavior using a novel laboratory testing technique

A testing system composed of pull-out testing apparatus simulating frictional behavior of anchoring solid-soil interface and the corresponding devices and techniques of specimen preparation are developed to study the real response of the anchoring solid-soil interface for anchor system under tension, especially to obtain more accurately the whole journey curve of shearing stress and displacement containing the shearing residual portion. This testing apparatus and techniques are simple and operable, which can be adopted to simulate the laboratory pull-out tests on anchoring system in bulk under multiple circumstances. Four groups of pull-out tests under twenty-seven different circumstances are completed on this testing system, and a novel whole-journey constitutive model for the anchoring solid-soil interface is proposed after investigating deeply the influences of curing period of anchor solid, pull-out speed and other factors on the interface shearing strength. The results indicate that the interface shearing strength increases slowly after curing for fourteen days, that the pull-out speed affects slightly the interface shearing strength in the range of 0.1~2.5 mm/min, and that the proposed constitutive model for the anchoring solid-soil interface is able to give calculated curves with good agreement with the test ones.