Soil Arching Effect And The Support Design Research Of Micro Pile In Slope Reinforcement

The Micro-pile has been widely used and achieved good effect and economic benefits inenginering with its characteristics of fast construction, flexible combination and smallconstruction site since its first applied in1950s. However, the method to calculate thespacing and theory on calculate the internal force in reinforced slope using micro-pile is littleand immature. So the method to calculate the spacing and the theory on calculate the internalforce in reinforced slope using micropile has been in-depth and systematic researched in thispaper through the methods of theory analysis and numerical simulation based on home andabroad study, which has make a promotion in using the micro-pile to reinforce the slop. Themain contents and conclusions of this study are as follows:(1) In this paper, according to domestic and foreign research status, summarized thecommonly used type of in the actual engineering, and introduced the difference between themicro-pile with anchor bolt and soil nailing.(2) The analysis in three-dimensional numerical simulation of the post-pile soil archeffect of the micro-pile that is the mainly interaction has been done in this paper. Bysimulation calculating, the existence of the post-pile soil arch effect of micro-pile has beendemonstrated then the formation mechanism of the soil arch effect has been analyzed, andsimulate the soil arch effect with different depth, landslide and different spacing thenanalyzing the law. Come to the conclusion that the pile spacing is the most significantinfluence on the soil arch effect..(3) By analyzing the formation mechanism of post-pile soil arch effect of micro-pile andcombining the anti-slide piles’ spacing analysis method, the rational spacing calculationmethod of the micro-piles been put forward. Based on to the formation conditions of the soilarch, that is, the middle section in soil arch and the triangle compression area at the arch foot will not failure, the micro-piles’rational pile spacing calculation formula was obtained.(4) Based on the micro piles’ rational pile spacing calculation formula, the post-pile soilarch effect factors have been detailed analyzed. Analysis showed that the micro-piles’rationalspacing directly influenced by the external loads, internal friction angle and cohesive stress.(5) Summarized the force calculation method of micro-pile in slope reinforcement andcompared the advantages and disadvantages of the existing methods. Finally, based on the p-ycurve of elastic-plastic foundation coefficient method and considered the impact of the axialforce, deduced the finite-difference formula to calculate the internal force and displacement ofmicro-pile in slope reinforcement.(6) Base on the mechanism, stress distribution and failure mode of using micro-pile toreinforce slope, then combined the reinforced slope design method, finally design a themicro-pile supporting to reinforce slope with an specific engineering.