Finite Element Analysis of Cantilever and Anchored Sheet Pile Wall using Plaxis 2D

ABSTRACT

Retaining walls are structures used to retain soil, rock or other materials behind the wall. Hence, they provide a lateral support to slopes of soil, vertical or near vertical, which would otherwise collapse. The retaining walls are commonly used in various projects, e.g. terraces for agriculture, buildings, railways, and roads. Retaining walls are generally classified as gravity, semi-gravity, non-gravity cantilevered, and anchored walls (Das 2008). The gravity walls are constructed with plain concrete, stone masonry or reinforced concrete and they depend on their own weight. Therefore, this type of construction is not economical for high walls and cannot be used when deep foundations are required. Semi-gravity retaining walls are most economical at low to medium wall heights, and they rely more on structural resistance through cantilever action of the wall stem. Generally, the backfill for a semi-gravity wall rests on part of the wall footing, so these walls should only be used when their foundations can be designed to limit total and differential settlements to acceptable values (WSDOT 2009). The non-gravity cantilevered walls do not rely on its mass to retain the soil, as opposed to a gravity wall. They rely on their flexural strength to retain the backfill soil, supported by their own penetration into the soil. This type of wall is constructed of vertical members consisting of partially embedded soldier piles or continuous sheet piles. Non-gravity cantilevered walls depend on the passive resistance at the bottom of the wall and the moment resisting capacity of vertical wall (California DOT 2004). While relatively shorter walls can be cantilever, higher walls require anchors. Anchored walls are similar to non-gravity cantilevered walls except that anchors embedded in the soil/rock are attached to the wall facing structure to provide lateral resistance are used to support walls and resist high lateral pressures acting on the wall. This study provides an insight on the effect of increasing wall penetration depth on the structural behavior of cantilever sheet pile walls. Although increasing wall penetration depth can be costly, it may be one of the most efficient ways to reduce the wall deformations and maximum wall bending moments.

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