The Homogenized Joint Element And Its Application In Engineering

At present, there are two common methods for the study of jointed rocksrone is simulating the impact of the joints by using special joint element and carrying out finite element analysis, the other is employing equivalont model to model the effect of joints. Using special joint element is convenient and workable in general. But, as joints are throughout the crude rocks, this method is certainly hard to achieve. The conventional body element cannot accurately deal with this problem. Especially, in many engineering problems, the media to be analysed have discrete discontinuities such as rock masses including a finite number of joints, soil-structure and soil-reinforcement interface, localized shear cracks. In this case, equivalent model is applied commonly.In this paper, a homogenization technique is applied to introduce a new interfaces or joint element for the finite element analysis of media having discrete discontinuities, the new element can be called homogenized joint element. The joint or crack is treated as inclusion in the media. Using an average rule, the influence to the joint is smeared into a small region of the adjacent intact material. The constitutive model in the region is defined in terms of constitutive properties of both the intact material and the joints as well as the geometry of the homogenized domain. Thus, the homogenized joint element includes the joint as well as the neighbouring intact rock on either side of the joint. The problem reduces essentially to that of defining the average mechanical properties for this element, which can be derived from properties of constituent materials and their respective volume contributions.Application of the homogenized joint element is illustrated by several examples in this paper. The results will be compared either with analytical solutions available or with the conventional finite element solutions having standard continuum element. In these examples, the feasibility and superiority of the homogenized joint element can be revealed from different aspect. Then the homogenized joint element is applied to model the effect of joint in the foundation of a gravity dam.