Study On Anchorage Mechanism And Bearing Performance Of Pressure Type Anchor

There are two common failure modes in the anchoring section of the pressure anchor: First,the grouting body of the anchoring section has an interface debonding failure due to reaching the interface’s ultimate bond strength;Compression failure occurs under the pressure of the pressure plate.The research work of this paper is mainly focused on the problem of Poisson effect of the pressure type anchor grout.Considering the radial deformation of the grout due to compression,the Poisson effect is used to anchor the pressure anchor,the critical anchor length and the grout body.Study on the influence of pressure bearing performance.Based on the interface debonding failure,the analytical solution of the interfacial shear stress and the axial force of the cross section of the grout and the calculation formula of the critical anchorage length are considered when the Poisson effect of the grout is considered.Based on the compression failure,the analytical solution for the bearing capacity of the grouting body under compression failure was derived.Through experimental research,the failure law of the grouting body under compression failure under different restraining capabilities was analyzed.The body is affected by compressive strength.(1)Considering the Poisson effect of grouting body,the analytical solutions of shear stress at the interface of the pressure anchor and the axial force of the section are deduced,and the Poisson effect coefficient is used to quantitatively analyze the influence of the Poisson effect on the load transfer law of the anchor.The existence of Poisson effect makes the interface shear stress distribution more uneven,and the length of the anchoring section,which plays the main bearing role,is significantly reduced.The influence of various influencing factors on the Poisson effect of the grout is analyzed.(2)Derived the formula for calculating the critical anchor length of pressure anchors,analyzed the influence of related parameters on the critical anchor length,and proposed that in engineering practice,0.65 times the theoretical calculated value of the critical anchor length can be taken as the optimal critical anchor for engineering length.(3)Carry out experimental research on the compressive bearing capacity and failure characteristics of the grouting body,set up three types of restraint rings of different thicknesses to simulate the restraining capacity of the pressure type anchor grouting body under different conditions of anchoring rock and soil,and The failure characteristics of grouting body under pressure were studied.(4)Based on the theory of limit bearing capacity of the foundation,based on the analysis method of limit equilibrium,the theoretical solution of the pressure bearing capacity of the pressure-type anchor grouting body is derived and compared with the experimental values.