Analysis of Underground Concrete Structures in Weak Soil Profiles

Abstract

Underground concrete structures are widely used in mega construction projects in newly developed areas in Egypt, especially in East Port Said. Designing these structures considering such site conditions in Port Said soil is an engineering challenge. This paper provides general guidelines for the designers for the expected behavior of the underground structures constructed at different depths considering many design parameters. A 2D numerical model using Plaxis software is created with the soil parameters and water table of this site. Mohr-Coulomb model for the sand soil layer and Hardening Soil model for the clay soil layer are used. The effect of overburden depth and the structure width in case of whether surface structure is constructed near the underground one or not. The effect of changing the number of floors of the surface structures and the distance between the surface and the underground structures. Moreover, the effect of construction of an adjacent underground structure is also studied. The maximum vertical settlement, the max. internal forces induced in the structure: maximum normal force and maximum bending moment are used to describe the structural behavior. Design recommendations and guidelines were drawn to facilitate the design of these types of structures in such site conditions.