Study On Mechanical Behavior Design Optimization Of New Board-Chair Retaining Structure On The Slope

Limited by route selection and construction cost, lots of steep embankment engineering with high embankment and deep covering soil appear. Oridinary railway supporting and retaining structure can’t meet the requirements of slope stability and deformation requirement of substructure, so a new retaining structure that can apply to this special terrain and meet the requirement of design life is to be put forward. The new board-chair retaining structure on abrupt slope has the features of pile-plank retaining wall and portal double row anti-slide pile. It not only meet the deformation requirement of high embankment, but also play a part in shirnk slope toe and diminish land occupation. Because this structure is firstly applied to project practice and mechanical behavior and deformation characteristic of it are not definite, study on mechanical behaviorand design optimization of new board-chair retaining structure on abrupt slope is a very frontier and urgent task.Firstly, based on board-chair retaining structure of Xuyong-Dacun Longshan station, the domestic and foreign current state of retaining structures on abrupt slope is fully investigated. Referred to calculation theory of pile-plank retaining wall and portal double row anti-slide pile, the board-chair retaining structure is devided to pile-plank retaining wall and portal double row anti-slide pile and caculated. Besides, a new calculation theory which can be applied to board-chair retaining structure on the slope is put forward and analytical solution is obtained.Secondly, ABAQUS which is nonlinear finite element analysis software is adopted and a three dimensional finite element model is established. The internal force distribution and eformation characteristic of new board-chair retaining structure on abrupt slope with deep covering soil are analyzed. The pile-soil and board-soil interactions are simulated by penalty contact. The size distribution characteristic of pile-soil and board-soil interactions is anayzed, which is contrast to theoretical calculation in order to verify the accuracy of theoretical calculation. Besides,2D finite element models are established to simulate the structure. The structure type and clear spacing and anchorage depth and so on which are sensitive parameters are effectively analyzed in order to provide theoretical support for future structure design.At last, based on SAP2000, the board-chair retaining structure of Xuyong-Dacun Longshan station is structural designed. The structure is optimized from bearing plate selection and anchorage depth, and the suitable parameters are put forward, such as structure size etc. Based on upper analysis, the mechanical behavior and deformation characteristic and design optimization of the board-chair retaining structure are analyzed and discussed. A set of calculation theory is put forward and structure size parameters are optimized in order to provide references for popularization and application of the structure.