High Slope Stability Of K1415+200 In Liu Nan Freeway Renovation And Expansion Project

With the rapid development of social economy, some of the early construction highway has been unable to meet the growing traffic demand, the renovation and expansion of the old road has become a trend. In the process of renovation and expansion of the old road, high fill and deep dig sections are inevitable. So high slope stability problem has been one of the hot issues in the engineering studies recently. This article is based on K1415+200 left slope of Liuzhou and Nanning Expressway Rebuilding and Extending Project. First, use engineering rock mass quality combined Hoek-Brown empirical formula to determine the main mechanical parameters of the original rock and soil slope. Then analysis the slope stability by using the numerical analysis methods, focus on the stress-strain variation during the high slope excavation and reinforcement. Preferably from bolt supporting scheme and stabilizing piles pre-reinforcement scheme to provide reference for engineering practice. The main contents and results are as follows:(1) Evaluate the quality of K1415+200 cutting slope by these six basic factors:Intact rock material strength, Core quality index, Structural surface spacing, Structural surface conditions, Groundwater conditions and Structural surface adjustment. Quantify the value according to the actual working conditions. And then determine the main mechanical parameters by Hoek-Brown empirical formula on this basis.(2) Set different levels on three factors include the bolt length, inclination and spacing based on orthogonal design principles. Obtain various factors affecting significance. Optimize the slope bolting design. Analysis of slope stability after reinforcement optimized design.(3) In the stabilizing piles pre-reinforcement program, compared to adding anchor and without anchor two different conditions and establish the corresponding numerical model. Analysis the stress and strain contours during slope reinforcement process. Explain the necessity of the use of pile-anchor structure.(4) Considering various factors, comparing bolt supporting solutions and stabilizing piles pre-reinforcement program from the stability requirements, construction technology and construction techniques as well as aspects of the total project cost. Choose the bolt supporting solutions is more reasonable for the K1415+200 slope reinforcement.