Structural reliability analysis of a dike with a sheet pile wall: Coupling Reliability methods with Finite Elements

Structural reliability analysis of a dike with a sheet pile wall: Coupling Reliability methods with Finite Elements

Rippi, A.

Jonkman, S.N. (mentor)
Schweckendiek, T. (mentor)

Civil Engineering and Geosciences

Hydraulic Engineering

Hydraulic Structures & Flood Risk

2015-11-25

Some dike sections in the Netherlands failed to comply with the safety standards and one of the most promising countermeasures is the construction of retaining walls inside the dike. The Dutch design codes for dikes with retaining walls rely on Finite Element Analysis (FEM) in combination with partial safety factors. However, this can lead to conservative designs. For this reason, in this research, a reliability analysis is carried out with FEM calculations aiming to demonstrate the feasibility of reliability analysis for such a soil-structure interaction problem. The case study concerns a (river) dike with an anchored sheet pile wall modeled in PLAXIS. The sensitivity and reliability analyses were enabled by coupling the uncertainty software package OpenTURNS and PLAXIS through a Python interface. The most relevant (ultimate) limit states concern the anchor, the sheet pile wall and global instability (soil body failure). The case was used to investigate the applicability of the First Order Reliability Method (FORM) and Directional Sampling (DS) to analyzing these limit states. Finally, also the system reliability was evaluated using sampling-based methods (DS). Due to the considerable number of random variables, before starting the reliability analysis, a sensitivity analysis was conducted for each limit state. This indicated the most important soil layers to be accounted for and the variables to be considered as stochastic. The sensitivity analysis and later on the reliability analysis, were based on analytical formulations of the limit state functions. The anchor and the sheet pile limit states were formulated in terms of their yield stress; for global instability, loss of equilibrium in the FEM analysis was used to define failure. Moreover, the system’s reliability was evaluated by taking into account all the three limit states that were mentioned previously. The goal is to implement the coupling between FEM and reliability methods in order to analyze the components of such a system (i.e. anchor, sheet pile wall and dike’s soil body), estimate the probability of failure and identify the most important soil properties that affect the behavior of each component and the system as a whole. The results of this research can be used to assess and optimize the current design procedure for dikes with retaining walls.

finite element method
reliability
dike
sheet pile wall
system failure

http://resolver.tudelft.nl/uuid:09edf3ae-6818-4c17-bd25-8b3f3414b6b8

Student theses

master thesis

(c) 2015 Rippi, A.