Analysis On The Geosynthetic-reinforced And Pile-supported Composite Foundation: Theories And Applications

Geosynthetic-Reinforced and Pile-Supported (GRPS) Composite Foundation is a kind of foundation composed of vertical enhancement and horizontal enhancement. Firstly, the thesis introduced its development history, application in projects, mechanisms of load transfer, existing computational methods and unfathomed problems. Then, a new method was put forward in designing and calculations, which gave a valuable reference for further researchs.Main works in the thesis are listed as below:(1) Based on elastic theory and tensioned membrane theory, a study has been conducted to investigate geosynthetic-pile-soil interactions. A simple theoretical approach to predict the deformation behavior of geosynthetics is presented in this thesis. The effects of pile modulus and pile spacing on the differential settlement, the stress concentration ratio and the tension in geosynthetics are discussed. The proposed method is verified with existing finite element analysis and a reasonable agreement is obtained.(2) A set of numerical modeling are performed using Plaxis program. The results of the numerical study demonstrated that inclusion of geosynthetic in earth platforms can reduce the total and differenial settlements above the pile heads, and at the ground surfaces, promote efficient load transfer from the soil to the piles and reduce the possibility of soil yielding above the pile heads. Analysis data indicated that the soil arching ratio decreases with an increase in the height of embankment fill, an increase in the elastic modulus of the pile material, and a decrease in the tensile stiffness.