Reliability Analysis of Modern Geotechnical Codes for the Limit State Design of Sheet Pile Structures Considering Parameter Uncertainties

Abstract

In this paper, the limit-state and direct probability-based design responses of modern geotechnical codes are characterized according to parametric analyses of geotechnical uncertainty. The reliability levels (β) of the limit-state design (LSD) responses are compared with the prescribed minimum target reliability indices (βT,min) of the codes for a case study that involves the design of an embedded sheet pile structure subjected to water pressure, seepage pressure, and no retained earth pressure. The effect of soil uncertainty, represented by the variabilities of the effective soil friction and the soil unit weight, on the direct probabilistic-based design responses, is analyzed at small- and high-reliability levels (0 ≤ β ≤ 5). The results show that the reliability levels of the LSD responses of the North American and European codes do not fulfill the prescribed βT,min for the overturning and structural failure limit-states. In contrast, for the hydraulic heave limit-state, the prescribed βT,min of the North American codes are widely exceeded. The effects of the uncertainties of the effective soil friction COVϕ′ and the soil unit weight COVγ on the normalized embedment depth (D/H) and the normalized maximum structural bending moment (Mmax/γH3) are also explored relative to the principles of the North American and European codes.