Analysis Of Soil Arching Effect And Soil Pressure Of The Scattered Row Pile-Soil Nail Compound Supporting System

At present scattered row pile-soil nail compound supporting system haswidely been used in coast’s foundation pit and slope,it is the new type ofsupporting method,which based on composite soil-nailed wall supportingtechnology,the deformation is resisted by combining the scattered row piles withsoil nail and anchor rod.Soil arch is formed between scattered row piles,theearth pressure in the front of arch is loaded by the facing,the earth pressure inthe behind of arch loads to the scattered row piles both sides,its deformation hasreduced greatly relative to traditional soil nail supporting.But theoreticalresearches of this supporting method are still immature,at present there is not acomplete calculation theory,therefore thorough theoretical research may benecessary.This paper is based on the analysis of soil arch between the piles,then theearth pressure of behind piles and soil arch behind facing, axial forces of soilnail are studied respectively by the method which combined theoretical analysiswith numerical simulation and calculation of construction practice,the maincontents are as follows:1.Analyzed the type and mechanism of soil arch in scattered row pile-soilnail compound supporting system, then simplified calculation model of soil archis put forward,and analyzed force analysis of soil arch,finally calculationformula of the biggest spacing between the piles is reached.2.Analyzed earth pressure behind the scattered row piles based on analysisof the biggest spacing between the piles;and analyzed of soil arch behindfacing,then earth pressure on the soil arch behind facing are obtained.3.Scattered row pile-soil nail compound supporting system is analyzed anddesigned based on a deep foundation pit project,and specific numbers are used inthe calculation formula,then the calculated results are better consistent with themeasured results in the field.4.Analyzed soil arch effect,deformationand axial forces of soil nail in theexcavation course of foundation pit,which based on the large-scale numerical simulated software,then the comparison made between simulation results andmeasured results, where the two results basically coincide with each other.