Limit State Design Method Research Of The Slab-Pile Wall Structure

In recent years, along with the development in railway construction, the Slab-Pile Wall, an approach to slope, has also been applied. A systematical research of the reliability of Slab-Pile Wall is carried out in this paper, in which the design method of Slab-Pile Wall is transferred from Allowable Stress Method to Limit State Method which is based on the reliability theory. This, on one hand, is a necessary and technical preparation for future revising work of retaining structure design codes for railway subgrade. On the other hand, it lays the foundation for the deep study on the reliability of the Slab-Pile Wall. This paper is part of the research on Railway subgrade Retaining structure limit state method by Ministry of Railways.The main works include to apply the Calibration Method to determine the general reliability standard for the existing structure and a unified reliability index for the structure future design by extensively collecting relevant literature and documents. For the three main failure modes (the flexural failure and shear failure of the Slab-Pile Wall, the soil failure of the piles at the anchor section), corresponding limit state equations are respectively established after deep analysis and theory study. On this basis, the random variables and the corresponding statistic parameters are determined.The main results are as follows.(1) The reliability indexes of the Slab-Pile Wall in three failure modes are calculated respectively with the Monte-Carlo Method through the FORTRAN language. Take the average and determine the target reliability index.(2) By comparing the applicability among the linde linear separation method and the general separation method, finally we choose general separation method to calculate. With the general separation method, the resistance and load factors are obtained, and the design checking expressions in the partial coefficients form are derivated subsequently. Therefore, the partial coefficients design method based on the reliability theory is established.The above study provides a significant theoretical basis for the engineering design of the Slab-Pile Wall with the reliability method, which could also be a good reference.