Research On Numerical Simulation Of The Grading Supported Slope With Frame Pre-Stressed Anchor

In recent years, as the main reinforcement method, the frame structure with prestressed anchors has been widely used in the supporting of foundation pit engineering construction and the reinforcement of high steep slope. This method has the advantages of low cost, short construction period, convenient construction, reliable reinforcement, less investment, and so on. The theoretical study often aims at the singal or multiple layers slope, and the multistage slope is rarely involved. But in practical engineering, in order to satisfy the stability requirement, the gradual slope method is usually adopted. Then the slope forms a ladder. At present, the theoretical research lags behind the engineering practice. Therefore, the theoretical research and mechanism of the frame structure with prestressed anchors for grade slope should be futher explored and analysised.In order to investigate the anchorage effect of the frame structure with prestressed anchors in grade slope, by using FLAC-3D program and strength reduction method, the stability of a two grade slope example before and after reinforcement is analyzed and calculated with numerical simulation technology. The main research contents are as follows:(1) The form and the advantages in engineering application of the frame structure with prestressed anchors are described, and the basic theory of anchor is introduced.(2) According to the mechanical principle of slope reinforced by anchors, the research idea adopting circular slice method is determined. On the basis of the stability analysis of single stage slope, the shape of slip surface is simplified as a circular arc, and the evaluation formula of slope stability is established. Then a kind of fast search method for the most dangerous slip surface is put forward. Finally, the simplified calculation model of the frame structure with prestressed anchors for the grading reinforced slope is obtained.(3) By numerical simulation technology, the safety factor change laws, the horizontal displacements, the vertical settlements of the slope before and after reinforcement are contrasted. The distribution laws of shear strain increment and the axial force of anchors are obtained.(4) Based on the numerical simulation analysis software FLAC-3D, the influences of various parameters on the slope safety factor, soil displacement and anchor axial force are analyzed. The mechanism of the anchor support is understanded more deeply, which provide some references for the engineering design.