Study On The Behavior Of Pile Plate Retaining Structure With Restraint In Front Of Pile Under Different Embedded Soil

The constrained pile-plate supporting structure in front of the pile is a new type of supporting structure based on the improvement of the traditional cantilever pile.The main purpose of this article is to further promote the application of this new type of supporting structure based on previous studies on this new type of supporting structure and solve the problems encountered when facing complex geological embedding conditions on the supporting site.The main research work and results of this article are as follows:(1)The stress analysis of the constrained pile-plate supporting structure in front of the pile is carried out,and the surface of the embedded soil is divided into an upper pile and a lower pile for calculation.The experiments conducted and the results calculated by the aid of MIDAS/GTS NX finite element software in this paper are mutually demonstrated.Considering the trapezoidal load at the restraining plate,the static balance and moment balance of the supporting structure are calculated from the perspective of the supporting structure as a whole.(2)With reference to a project example,in the MIDAS/GTS NX finite element software,the working conditions of the project are simulated.Substitute the material properties of typical soils in Chongqing,such as limestone gravel soil,sand-mudstone gravel soil,and silty clay,to calculate the models of these three types of different soils under the same embedding conditions.It can be seen from the calculation results that the maximum displacement of the pile top of limestone gravel soil,sand-mudstone gravel soil and silty clay can meet the qualified standards for engineering use under the thickness of three-meter embedded soil.In terms of the maximum displacement of the pile top,the optimal supporting effect is the embedding conditions of limestone and gravel soil,followed by sand and mudstone and gravel soil,and the supporting effect of silty clay is the worst.From the point of stress distribution curve and extracted key points,the stress of pile body is roughly the same.The stress at the rib of the pile is the largest,followed by the boundary between the pile and the restraint plate,and the stress direction is opposite to the rib.The higher the supporting and embedding strength of the soil,the greater the stress on the pile.Through the simulation calculation of the cantilevered retaining wall under the same embedding conditions,it is found that the displacement of the pile top is very large under the more expensive rock embedding depth,which shows the superiority of the constrained pile-plate supporting structure in front of the pile.(3)Take out three kinds of soil,limestone gravel soil,sand mudstone gravel soil,and silty clay separately,and study that under the same nature of embedded soil,different embedded thicknesses are for constrained pile plates in front of the pile Influence of the properties of supporting structure.Through modeling and calculation,it can be known that when limestone crushed stone soil is used as embedded soil,the thickness of limestone crushed stone soil can reach the displacement of seven meters at the depth of two meters of rock-embedded rock,which can also meet the engineering use standards.When the thickness of sand and mudstone gravel soil as embedded soil reaches seven meters,it exceeds the engineering use standard.By deepening the depth of embedded rock,it can meet the requirements of use.When silty clay is used as embedded soil,the embedded thickness of three meters can meet the engineering use standards,and the thickness beyond three meters is not satisfied.When the embedded thickness reaches seven meters,even if the depth of the embedded rock is deepened,the displacement of the pile top does not meet the engineering use standard,and other solutions need to be found.The stress distribution law of the supporting structure is also roughly the same as before.(4)Regarding the strengthening measures of weak embedded soil,this paper mainly introduces the two methods.One is to increase the size of the support structure.By increasing the size of the support structure,the stability of the support structure can be improved,thereby achieving the effect of safe support.This method is usually not economical.The second is to use the grouting method to improve the bearing capacity of the soil in front of the pile to meet the qualified support standard in the project.Through modeling and calculation,we can see that the two methods of grouting and increasing the size of the supporting structure have a good effect on improving the supporting conditions.