BEHAVIOUR OF TIE BACK SHEET PILE WALL FOR DEEP EXCAVATION USING PLAXIS

Dinakar K N, S K Prasad

Abstract: With the increase in urban population and technological progress, people’s demands for a comfortable life have also increased. Shortage of space for parking, public amenities and housing utilities has made necessary to use underground spaces. Deep excavations in urban areas require special measures due to the presence of structures, underground utilities and other engineering constructions existing in the vicinity. Deep excavations are supported by systems like conventional retaining walls, sheet pile walls, braced walls, diaphragm walls and pile walls etc. The design of support systems for deep excavation requires careful analysis, design and monitoring of performance. As such, the performance of support systems for deep excavation requires careful consideration of soil-structure interaction. In this study, 2D Finite element model is developed using PLAXIS to represent the performance of anchored sheet pile wall, stress analysis and deformation characteristics of ground and bending moment distributions in sheet pile wall at all vulnerable locations are identified. The analysis is carried out considering non-linear behavior of soil using Mohr-coulomb failure criteria. The input data include typical building loads, prestressing forces, soil parameters and thickness of sheet pile and hence one of the main focuses is to identify their effects on the performance of tie back sheet pile walls. Results of the study reveal that sheet pile wall method is viable to limit ground movements due to the excavation. Besides, the parametric study shows that considerable reduction in wall deformations and bending moments can be achieved and safe excavation to greater depths is possible with the introduction of tie back sheet pile wall support system.

Keywords: Deep excavation, Tie back sheet pile wall, Non-linear behavior, Mohr-coulomb criteria

DOI: https://doi.org/10.15623/ijret.2014.0318016