Analysis Of Deformation Properties Of Fill Subgrade In Pile-Plank Wall Applied In Steep Slope Foundation Of High-Speed Railway Based On Field Monitoring

With the development of China’s high-speed railway, the deformation characteristics of embankment retaining structures for some special terrain caused widespread concern in the engineering sector. The cantilever height of pile-plank wall can break through the high limit of ordinary retaining wall due to pile anchoring section which depth to stable formation can withstand lateral thrust. With the increasing length of the pile cantilever, the pile lateral displacement increase under the action of embankment filled soil and additional settlement of embankment have a corresponding increasing. High-speed railway control subgrade settlement extremely strictly and the embankment settlement caused by piles lateral deformation cannot be ignored. The present study of the relationship between the lateral displacement of the piles embankment and embankment additional settlement which caused by it based on field tests are little. Paper combines the field in-situ tests of steep foundation embankment pile-walls which are from Cheng-Yu passenger line and Gui-Guang passenger line to study the earth pressure on the back wall, embankment settlement and horizontal displacement of the pile. Combined with finite element numerical calculation, study the lateral displacement of embankment piles and embankment additional settlement which it causes and the interaction between the two. The main work and conclusions are as follows:(1) A complete monitoring system of site was established in Cheng-Yu passenger line pile-plank wall test section. At the same time collect the site data of the earth pressure of back wall, lateral displacement of piles and embankment settlement. Moreover, get a lot of field data.(2) Through on-site monitoring data analysis, w成渝客运专线e get the conclusions of the lateral earth stress increase with the embankment fill height increasing on the same height during the embankment filling process. The distribution formula to soil stress of the back wall along the back height after the completion of embankment filling has two points. The first is soil stress increase decreases rapidly after the first increase and then slow increase from the top of the wall to the end of the wall. The second is the soil stress decreases first and then increases gradually and stabilize finally with time developing.(3) Analysis shows that anti slide pile The lateral will produce displacement From the direction of embankment under the action of The backfill.The maximum displacement occurs on the pile top,value for6.55mm.At the same time, embankment settlement measured data show After complete filling sedimentation value increased with the time,the initial settlement increase fastly,then gradually decrease and stabilize.The distribution trend of Subgrade settlement along the line of transverse is same as trend surface. Using finite element method to find the ratio of the settlement after construction of embankment and anti slide pile horizontal displacement is about19.67%.(4) Combined with the site data analysis and finite element simulation, proposed a anti-slide pile design concept based on the deformation control for the same or similar conditions. The concept helps to control the embankment settlement caused by lateral of anti-slide pile.