| At present,the traditional single support structure can not meet the actual needs for high slopes with complex geological conditions and special requirements for supporting space.The combination of double-row piles and cantilevered retaining walls can better solve this problem.The problem is that this composite structure generally separates the upper and lower parts separately and does not consider the force coordination and the overall support stability between the upper and lower structures,which leads to a deviation from the actual design results.This paper takes the composite structure of double-row piles and cantilevered retaining walls as the research object,and studies the differences between the separate design of the composite structure and the combined support design by means of numerical simulation methods,and analyzes the changes in the internal forces of the composite structure under the changes of the design parameters of the rock and soil and the pile body.law.The main research work is as follows:(1)The model is simplified.Select a practical project case,select the calculation parameters of the soil and retaining structure,and simplify the model of the slope and the combined retaining structure according to the commonly used separate design and overall joint design method in the project.(2)Numerical Simulation.The finite element analysis model of the double-row pile and cantilevered retaining wall combined structure was established by numerical simulation.According to the results of the internal force of the composite structure,the internal force variation feature points were selected.(3)The individual design method is compared with the overall joint design method.Three design simplification models were established using the separate design method and the overall joint design method.Three kinds of simplified models were used to perform numerical simulations to obtain internal force changes of the retaining wall and double row piles.The differences in the actual structure design of the combined structure were compared and analyzed.Slope support effect.(4)Analysis of the characteristics of soil under the change of soil parameters.Based on the numerical simulation of the composite structure,the main influencing factors of the soil material supported by the slope are selected,and the Monte Carlo random sampling method is used to generate a random sample set of soil parameters to study the double-row piles under the change of rock material parameters.With the force characteristics of the internal force characteristic points of the combined structure of the cantilevered retaining wall,the effect of the variation of soil parameters on the internal force variation law of the composite structure is obtained.(5)Analysis of Force Characteristics under Change of Design Parameters of Piles.Studying the variation of force characteristics of the composite structure under different parameters,considering the effects of pile spacing,connecting beam size,and rock-socketed pile length ratios of the front and rear piles,the internal forces of the structure,the stress of the soil around the pile and between the piles,The design parameters are optimized to obtain more reasonable pile design parameters.Through this study,the main conclusions are as follows:(1)The separate design method of the combined structure in the engineering is conservative in comparison with the overall combined support design method,and it is easy to cause material waste.(2)Using Monte Carlo random sampling to obtain the sample group for finite element calculation shows that the position of the feature points of the internal structure of the composite structure has very little change.(3)Considering the influence of various factors,the distance between piles is 4m.The section size of the tie beam is the same as the section size of the pile body.The depth of the rock plugs in the front and rear row is 4m. |
