The Application Of Soil Nailing In Slope Engineering And The Finite Element Analysis For Stability

With the rapid development of our national economy, the flourish of modern construction, various large-scale engineering projects have been under construction such as high-rise buildings, water resources and hydropower facilities, mines, ports, highways, railways and energy projects, etc. However, abundant slopes have been inevitably formed during the construction of those projects or during the operation after construction. As a result, analysis of slope stability has become important research content in rock mechanics. However, there are a lot of problems arising in project practices, such as misunderstanding of characteristics and attributes of slope projects, ineffective measures taken in regulation projects. Those problems always result in deformation and destruction of slope projects with serious damages and great loss, or in unnecessary waste due to over-conservative regulation schemes. Therefore, analysis of slope stability and careful selection of slope regulation schemes are of great importance to satisfy a double goal of safety and economy.First of all, the paper summarizes the developing course and current research status of soil nailing support, expounds the analysis methods and principles of soil nailing support, and introduces in detail principles and methods of soil nailing support structure design and concrete design contents on the basis of previous study of soil nailing. Furthermore, it expounds matters requiring attention in design calculation and stability analysis and introduces in detail the application of finite element strength reduction method in slope stability analysis by current standard design method, stability checking calculation and finite element strength reduction method.Then combine Changchun City Rose Valley quarry slope management projects, detailed description of the soil nailing structure parameters of the design process, and selection of Drucker-Prager constitutive model, based on the finite element ANSYS10.0 procedures strength reduction, the natural slope and soil nailing slope stability checking to determine reasonable soil nailing programmed. In carrying out finite element analysis, the slope of soil will be for the plane four discrete node isoperimetric element, the establishment of calculation model using finite element strength reduction through before and after processing, calculation results from the slope of the displacement, and plastic deformation regional trends by drawing within a point of the slope displacement and reduction coefficient curve to determine the relationship between the natural slope and soil nailing slope safety factor.According to the stability of the simulation analysis, the following conclusions can be drawn:(1)Based on strength reduction finite element method, the way to analyse the slope stability does not need to assume the position of failure plane. And the computational model satisfies the balanced equation of power and stress-strain relationship of soil body, can be used to simulate the natural process of excavation, which is traditional limit equilibrium method could not be achieved.(2)Application strength reduction method to analyse the slope stability, can get horizontal displacements of soil body under the different reduction factor, and determine the assurance factor by analyzing.(3) According to the normative experience, a reasonable and safe soil nailing parameter is determined and it satisfies the standards requirements of stiterion.(4)The assurance factor of the supported slope can be obtained by simulation that is 1.70.the stability of soil body significantly increase, but the displacement reduce, that is , soil nailing programme for Rose Valley quarry in Changchun City High Slope Support project is feasible and reasonable.