NONLINEAR ANALYSIS OF CONNECTED AND DISCONNECTED SOIL-PILE-RAFT SYSTEM UNDER EARTHQUAKE LOADING

Abstract

In design of High-rise buildings, the main issue is to transfer the subjected loads to the ground safely. So to prevent probable damages and to reduce the deformation, a proper design of foundation is required. In theses cases a combined piled raft foundation is being preferred from two to three decades. However, when the piles are connected to the raft, high stresses are generated in the piles. To overcome this problem a new approach, to disconnect the piles from raft forming a new type of foundation called disconnected piled raft foundation (DPRF), has been suggested. The work done in this field is very less specially under dynamic loads. The objective of this work to perform numerical analysis on connected and disconnected Soil-Pile Systems under different soil conditions and loading taking into account the nonlinear soil-pile-raft interaction modeling the interfaces appropriately using Finite element software PLAXIS 3D. Furthermore, the influence of geosynthetic reinforcements in the granular layer of disconnected systems should be investigated. In detail, the following subjects should be dealt with: Literature review on existing design approaches and guidelines combined pile raft foundations (connected and disconnected with and without geosynthetic reinforcement). Description of the load transfer mechanism of different system under vertical and horizontal loading. Representation of different modeling techniques of elements used in the system. Numerical simulation of connected and disconnected (with and without geosynthetic reinforcement) Soil-Pile-Raft Systems under dynamic loads. Comparison of the calculation results of the different systems with regard to the determination of the influence of various parameters on the load-bearing and deformation behavior. Evaluation of the achievements and identification of further research needs.