Experimental Studies On Anchoring Mechanism Of Bolts In Bedrocks

As a method which could reinforce the stabilization of the structure and the rock-soil mass, rock-soil anchor technology works with the shearing strength between the rock-soil mass and the anchor bolt. The structure and rock-soil mass were linked up by the anchor bolt which fixed in rock-soil mass. Compared with other methods which could reinforce the rock-soil mass, rock-soil anchor technology has lots of advantages. For its widly using, the research around rock-soil anchor technology will be useful.Mode test has been carried out in order to research the anchoring and reinforcing mech- anism which is one of the keys in the rock-soil anchor technology. Firstly, the effect between the drilling method and the roughness of the hole side and the effect between the drilling method and the peak shear strength between the grout and the bore were told based on the mode test. Secondly,it's introuduced that the mechanism of production of the mechanical inbuilt stress based on the analysis of the skin of deformed steel bars. Based on the test, it was certified that the grout could be expanded when it was sheared, and this could affect the peak shear strength between the grout and the bore. Thirdly, based on the analyse and the test data of hole 13#, the distribution expressions of the axial force and the shear stress are derived. At last, based on the test data, it's discussed that the ruling condition of the de- sign in rock-soil anchor project.Based on this mode test, we could draw the conclusion.The anchor bolts which were drilled by percussion-rotary drilling had lager bearing capacity then those which drilled by hard alloy drilling, and the anchor bolts drilled by diamond drilling had the least bearing capacity.The peak shear strength between the grout and the deformed steel bars was bigger then it between the grout and the round steel beacause of the radial stress and the mechani- cal inbuilt stress. It is pointed out that the peak shear strength may be larger then the perm- issible value of the peak shears.