Study On Work Mechanism And In-situ Test Of Pressure-dispersive Anchor

Geo-anchorage can make sufficient use of the potential of rock mass and soil, it is one of the most efficient technologies which solve complex geotechnical engineering problems. In civil engineering today, geo-anchorage technology is applied more and more widely. With the development of infrastructure constructions in our country, geo-anchorage technology is expected to meet more requests of the engineering circles, for example, the endurance capacity of anchor should improveï¼›the increment of bearing capacity of anchor should be proportionate to the increment of anchored segment length of anchorï¼›the use of anchor should not effect the exploiture and using of stratus all around, and so on. Tensile anchor can not solve these problems itself., thereby entering into the loading transmission mechanism and work capability of new types anchors looks so important. Pressure-dispersive anchor is one of the most representative new type anchors. But the study of work mechanism and rule of stress distribution of pressure-dispersive anchor is insufficient and the unitive understanding about it has not come to being. Based on the deformance-consistent premise, this paper combines the Mindlin elastic displacement result with the elementary theory of finite element, and educes the rule of shear stress distribution of pressure-dispersive anchor by calculating matrix equation. The analysis result is validated by ANSYS software according to plane axis- symmetry problem. Via calculation the paper proves that the stress distribution state of pressure-dispersive anchor is more rational than that of tensile anchor, and pressure-dispersive anchor has better work mechanism. Moreover, this paper also discusses the configuration,destroy-mode,endurance capacity,design and construction of pressure-dispersive anchor, contrasts different characteristics of pressure-dispersive anchor from tensile anchor, and analyzes the advantages of pressure-dispersive anchor in the aspect of engineering appliance performance.On the other hand, the study on work performance of pressure-dispersive anchor in rock stratum and weak rock stratum especially is not sufficient in the civil geotechnical engineering circles. In allusion to this, the paper has done a in-situ pull-out test of three groups including nine anchors. In the test, the destroy-mode of pressure-dispersive anchor in weak rock stratums was observed, and the test has proved that the bearing capacity of pressure-dispersive anchor increases rather evidently than that of tensileanchor in weak rock stratum medium. Moreover, this paper analyzes the factors which effects the the bearing capacity of pressure-dispersive anchor, as the space between of supported-load body and so on, and also explains the different characteristics of pressure-dispersive anchor from tensile anchor in the deformation aspect relying on test results like the P-S curve. The analysis results of this paper can offer some useful references to the appliance of pressure-dispersive anchor in Chongqing and other mountainous areas for the future.