Based On Soil Arching Effect Of Inner-force And Displacement Calculation Method Of The Portal Double Row Piles And Test

As a new bracing structure, the portal double row piles are developed in lastdecades, because of its many advantages, such as less displacement in the top of thepiles, reasonable force structure and larger rigidity, so it is widely used in the slope,as it can prevent and reinforce the geological disasters. But now the pile arch thrust,the soil pressure between piles, the force and displacement calculating method is notripe, it still needs to study the mechanism of force. Therefore, this paper that basis onthe experiment studies this theory, and it proposed a new force and displacementcalculating method of portal double row piles.Firstly, this paper discussed the internal force analysis and the formationmechanism of soil arching between the piles, summarizing the concepts of soilarching effect, formation mechanism, systematization, reasonable arch axis, stressanalysis and failure modes; On this basis, using the geometric characteristics of soilarching axis and the mechanical equilibrium and stress station at the foot of thearching, putting forward soil arching thrust distribution around the portal double rowpiles.Second, against the force and deformation characteristics of the portal doublerow piles, simplifying the force reasonably, setting up the double anti-slide pile andpile soil interaction model: the back pile withstand thrust that is bounded by thesliding surface, simplifying the soil arching thrust and the active earth pressure, thefront pile that withstand lateral soil resistance is calculated by the elastic groundreaction force "m" method, the soil pressure between the piles is calculated by the thinlayer element method. Then considering the different characteristics of pile segmentand the boundary conditions, the different characteristics of pile segment deflectiondifferential equation is obtained, solving with the finite difference method, andprepared the relevant calculation in Matlab, presenting a new method of solving theportal double row piles force and displacement.The current situation is lack of the portal double row piles’s model testinformation, designing and completing a small slope double pile model experiment,through measuring the pile strain and the resistance of the distribution of pile soil,further analysis to explore the double anti-slide pile structures carrying mechanism ofthe thrust load conditions and the force and displacement characteristics, based on testresults verify the reliability of the method of theoretical analysis. Finally, discussing the internal force and displacement with pile diameter (pile stiffness), the stiffness ofcoupling beams at the top of the pile, pile spacing, row spacing, the elastic modulus ofthe soil around pile by the single-factor method, getting the portal double row pilesmulti-factor sensitivity analysis results, then optimized to provide a reference for theengineering design of the portal double row piles.