Analysis Method Of Bolt Force Based On Hyperbolic Model And Its Engineering Application

China is one of the countries influenced by geological disasters most frequently.The Rock-soil anchoring technology is an important branch of geotechnical engineering,it use anchor cables or anchors to reinforce the rock.The Rock-soil anchoring technology can greatly reduce the self-weight of the structure and reduce the volume of the structure by fully calling and improving the self-stabilizing ability and the strength of the rock soil,is a kind of safe and reliable reinforcement technique which disturbing rock rarely and saving engineering materials,and it has been widely applied in tunnel foundation,slope support,Underground Structure and anti-float structure.However,due to the variety of anchoring mode and the complexity of reinforced rock soil,Although the mechanism of load transfer has been studied deeply by many scholars at home and abroad for a long time,but there are still many deficiencies in the research and application of anchorage technology,and there is still no unifying theory.In this paper,we adopt the method of theoretical analysis and numerical simulation and engineering examples,the load transfer mechanism of the bolt is studied deeply.At first,this paper summarized the research history and current situation of the load transfer mechanism at home and abroad,Furthermore,the problems existing in this research direction were presented.The technical characteristics and classification of bolt are expounded,and the load-bearing mechanism and the failure mode of bolt were analyzed.The interaction mechanism and mechanical behavior between the anchor rod body and grouting body and the grouting body and the rock-soil body in the load transfer process were studied.This paper was intended to analyze the bearing capacity by summarizing the commonly used load transfer models and their respective applicability.Secondly,this paper assumed a hyperbola relationship between the shear stress and the shear displacement,and introduced the hyperbola model to derive the non-linear differential equation,and the characteristics of stress distribution were analyzed according to the solution.It was shown that the distribution of axial force and shear stress along anchor rod is nonlinear,and the distribution of axial force appear as a concave diminishing curve,the shear stress is concentrated on the tensioning end and gradually transfer to the far end of the anchor.Finally,the accuracy of the load transfer solution is verified by the measured data.Thirdly,the pull-out bearing mechanism of anchor rod is analyzed by numerical simulation.The influences of the coefficient of comprehensive shear stiffness,the diameter of anchorage body and the ultimate shearing strength of anchorage interface on the stress distribution,the pull-out bearing capacity and the value problem in different geotechnical bodies were studied It can be used as the theoretical basis for the design of bolt and the selection of soil parameters.Finally,Based on the engineering example of the anchorage support of Changsha-Shaoshan-Loudi highway cut slope,this paper introduced the slope protection measures are proposed according to the geotechnical engineering conditions in practical engineering.The design process of bolt,the construction sequence and the pull test,and then,the calculation method of bolt load transfer in this paper is verified by the field pull test data.