Developing the composed coefficient technique for analyzing laterally loaded barrettes

Abstract

Extreme heavy-loaded structures cause massive axial and lateral loads, which need a special system of foundations to transmit these loads into the surrounding soils. Many structural problems, for these structures, arise mainly from large soil displacements. Barrette foundations can be a major solution for avoiding large soil displacement problems. Because it is large dimensions compared to piles, it reduces considerably displacements especially if the underlying layers contain weak soil. Barrette foundations already used in many foundation systems as in Entisar Tower and Creek Tower in Dubai and the Petronas Towers in Kuala Lumpur. In this paper, the composed coefficient technique (CCT) is further developed to be applicable for analyzing laterally loaded single barrettes. The technique accounts for the three-dimensional full interaction between the barrette and the surrounding soil. In the technique, the three-dimensional coefficients of the stiffness matrix of the barrette are decomposed to be one-dimensional. This enables easily adding these coefficients to those of the stiffness matrix of the soil. A series of validations is carried out to verify the application of the developed CCT. It is found that modeling the barrette by CCT gives approximately the same results when compared with three-dimensional finite element results. In addition, comparative studies of laterally loaded single barrettes in a real subsoil are modeled, in which East Port Said soil properties and stratification are considered, which is similar to soil formations around the world such as London, Frankfurt, Rome and Dammam. Different methods for determining the effective barrette height are discussed, and guidelines for engineers when analyzing laterally loaded single barrettes in East Port Said area are present. The proposed technique is implemented in the program ELPLA.