| China is in the period of rapid development of economic construction at present.There are a large number of landslides and other geological disasters to cause Chinese economic construction and people's lives and property great harm becase of human activities and natural causes, so engineering position in the engineering construction is very important. In the course of the process, however, because of the uncertain understanding of engineering characteristics and nature and inappropriate treatment measures,the slope appears deformation and damage again after treatment Oftenly In order to achieve safe, reliable and economical purposes, to analysis slope stability and choice of reasonable engineering management program is very important. In the foundation excavation and slope treatment the soil nailing cause peoplesattention and favor. becase of the advanced technology, light construction equipment, simple operation, less demanding conditions on the construction ,safe and reliable.This paper describes design elements of soil nailing and calculats the overall stability of the plus solid by the finite element analysis software base on the slope reinforcement of the second phase project in the Rose Valley.First of all, the paper summarizes the developing course and current research status of soil nailing.Then it describes the mechanism and the application scope, design principles and stability analysis in detail. In the finite element analysis theory,it introduces the mechanism of finite element stability analysis and the application of strength reduction, That is to make reduced soil shear strength as the shear stress under reduction factor. According to shear failure theory the shear stress can be express as the main stress at this point.In the plastic state it can establish a function between stress increments and strain increments through the plastic matrix. This allows to establish a link between reduction factor and deformation of the soil.We can obtaine the reduction factor in the critical state through analysis of soil deformation.That is safety factor.Constitutive relation uses Drucker-Prager yield criterion, associated flow rule, while not considering the dilatancy of rock and soil Project section make slope reinforcement of the second phase project in the Rose Valley as the design and analysis object. First of all, using the limit equilibrium method and finite element strength reduction calculat the natural slope stability. Safety factor is 1.05 calculated by arc destabilizing factor rendering.Strength reduction finite element use ansys software,choose Drucker-Prager constitutive models,to ansys the stability and obtain safety factor of 1.1.The safety factor of two methods are less than1.3 so that natural slope. requirs reinforcement .Then I use the lizheng software to design the structure of soil nailing. The calculated safety factor of against sliding and overturning meet regulatory requirements. Then on the finite element model of slope reinforcement, the safety factor is 1.7,meeting the specifications, that is to say Support program is feasible from the security aspect.At the same time ,I designe a retaining wall under the same conditions to calculate the construction cost. in these conditions, the soil nailing wall is more economical than the retaining wall.In carrying out finite element analysis, the slope of soil will be for the plane eight 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.The last part are conclusions and recommendations of this article. Conclusions summarize the calculation methods of the study and obtained data results. Soil nailing main parameters are as follows: support length 30m, maximum 8m, slope 70°; soil nail spacing 1.2m, soil nail angle 15°, the maximum soil nail length 12m, concrete cover thickness 120mm. Recommendations described the further researchin this paper. That is to analyze the dynamic stability of soil nailing body as three-dimensional problem. |
