Investigation of a Macro-Element Model for Shallow Foundations on Sand

Abstract

Larger and larger suspension bridges are being made. Therefore, tremendous forces will be obtained in the suspension cable, which must be anchored. A good understanding of the response of the foundation and its underlying soil during this kind of loading will then be necessary. To calculate and understand the soil intersection analyses is a time-consuming process, and reduction of the calculation time will be beneficial.

The calculation time may be reduced by introducing a macro-element model. In this model, the foundation and the underlying soil is represented in one single element, known as a macro-element. The number of degrees of freedom will be reduced, and good control of the structural response will be obtained. The macro-element model simplifies the analyses by using only one single element to describe the global behavior, which will reduce the calculation time.

In thisMaster thesis, a presentation of the macro-element model applied for shallow foundations on sand is investigated. Some background theory is presented together with the theory concerning the macro-element model. The mechanical behavior under a foundation of sand during combined loading is investigated through both finite element analyses and some prototype testing. The yield surface closer to vertical capacity has been studied, and it look like the yield surface in V-H plane is valid here as well. Overall, the finite element analysis matches the prototype tests.