Soil Nailing Wall And Pile Brace Combined Supporting Structure Characters And Stability Analysis

Soil nailing wall and pile bracing structure, as in recent years, the emergence of a new form of supporting structure, due to its full use of soil nail wall supporting structure and pile supported and supporting structure of their force characteristics, in ensuring foundation pit supporting safety conditions, greatly saves the cost, so as to get the wide application. But the combination of supporting structures, a theoretical study, lags far behind the practice. Therefore, this paper will of soil nailing wall and pile support combined supporting structure and the working properties of the overall stability of, for the promotion and development of this support has important significance.This paper first of combined supporting theory and the stability theory for the analysis, on the basis of theoretical research, using midas-gts simulation, followed by the analysis of the combined support support stress at the excavation stage of stress field and displacement field and to explore position and length of soil nail support on combination supporting stress field and displacement field effect; analysis of the combined supporting the overall stability of the structure, and to explore the soil nail length and brace position on the stability of the impact, finally in the practical engineering case, through the extraction of the actual monitoring data and the establishment of midas-gts model data were compared.Through the above finite element simulation and practical engineering analysis are obtained in this paper as follows:(1) supported composite support of soil nailing wall part analysis, should consider the effect of soil nailing stress redistribution and secondary displacement;(2) combination support and support change brace position of supporting displacement field and force field has greater impact and change the length of the upper soil nail is not sensitive;(3) the soil nailing wall simplified to an equivalent uniform load, pile bracing part of separate design, the maximum bending moment of pile body than the actual stress increases by about 30%, row piles design tends to be more conservative.(4) under the conditions of this study, combined supporting structure, the overall stability of performance for: plastic zone from the bottom pile and soil nailing wall at the bottom and, soil nailing wall of plastic zone development faster, eventually from the bottom of the slope through to the top of the hill appeared to disrupt, also appear in the bottom of the pile of slip surface, when the support stiffness is smaller or no support, will be transformed based sliding surface and combined support support stability damage in the form of the failure of the soil nailing wall, declared that the entire support type of damage, and the sliding surface compared to pure soil nailing wall slip surface after shifting and broadening.In this paper, we have made some useful work for the better understanding of the working characteristics and stability of the combined supporting structure, and put forward some suggestions for the current design.