Mechanical Properties And Their Experiments On Rock Bolt Foundation Of Wind Power Generation Towers

With the development of wind power industry in China,the design requirements of the fan foundation is also increased,it's been wind concerned because of the rock bolt foundation has the characteristics of simple construction,small amount of foundation excavation and high uplift bearing capacity.However,the research on the anchorage theory of rock bolt foundation is not mature at present,which was also restricts its development.In order to verify the reliability of rock anchor foundation,this paper conducted a series job of theoretical research and finite element numerical calculation,design and carry out the relevant type of pull ing test,and also established a relatively perfect results of theory and analysis.To delve into mechanical properties and working mechanism of rock bolt foundation,further verify the reliability of rock bolt foundation,this paper had carried out a lot of research work.The main contents are as follows:1.The force analysis was already done for the single rock bolt in this paper,gives the stress field and displacement field of single rock bolt foundation in the elastic stage,focusing on research the mechanical properties in the elastic-plastic stage of the interface between the anchor solid and the rock,the expression of shear stress and axial force was also deduced for the interface between the anchor solid and the rock in elastic-plastic stage.At the same time,we had already considering the influence under several concentrated force of single rock bolt foundation.In addition,the theoretical analysis of the interface between the anchor solid and the rock was also carried out,and we deploy the follow-up research work base on the shear stress distribution of the interface between the anchor solid and the rock.2.Through the finite element numerical simulation of ANSYS,the reliability of the theoretical results was verified.We had already analysed the effecting of free section depth on the shear stress distribution of interface between the anchor solid and the rock,and also considering the influence to the shear stress distribution of interface between the anchor solid and the rock on different parameters(anchor solid and anchor diameter,elastic modulus and the anchoring depth,etc.),the way to improving the shear stress distribution of interface between the anchor solid and the rock was put forward at the same time.3.Because of the uplift force formula for single rock bolt from the current code has certain limitations,this paper had completed the stress analysis of interaction between pile cap and foundation under considering the effect of interaction,the uplift force formula of prestressed rock bolt was given with considering the effect of calculation,then had verified the results by using finite element numerical calculation.Considering the rock weathering can influencing the stress of rock bolt foundation in actual engineering,this paper had made a simple numerical analysis method to simulation of rock weathering,the effecting of rock weathering to the rock bolt foundation was finally given.4.This paper had designed the rock bolt foundation uplift bearing capacity model experiment scheme under the results of theoretical research and finite element numerical simulation,the first stage of the test content was already done,the work of loading and data acquisition will begin at the first time when the maintenance stage is over.There are three aspects of theoretical analysis,numerical calculation and the true test in this paper was given to research of the rock bolt foundation,the research results has a certain reference value to guide the design of rock bolt foundation.