In this paper, a method of settlement analysis for buildings with a mat foundation is described by considering the rebound of the ground. When a building is constructed on soft ground, pile foundations are used to avoid the undesirable effects of ground settlement. In this case, however, a building may become detached from the ground. Various problems caused by this phenomenon have been reported. As a result, mat foundation has recently been employed for construction in consideration of these effects. A building with mat foundation, however, is greatly influenced by settlement. To counteract this, a method is being employed in which a large amount of earth is excavated from the building site of a structure in order to reduce the extent of settlement caused by its weight. Generally the ground rebound and the settlement are caused by the excavation and the weight of a structure, respectively. To estimate their effects, it is necessary to investigate how the excess pore water pressure in the clay layer varies with the time and to analyze the interaction between the ground and structure. We present the correlation between the mean consolidated pressure, and the coefficient of volume compressibility, mv, and the coefficient of consolidation, cv, based on the results of the cyclic consolidation test. And we have calculated the rebound and the settlement of buildings with a mat foundation from the excess pore water pressure obtained from mv and cv. From these results, we obtained that the properties of the ground settlement were changed from excavation period and starting time of the construction of the building and affected largely by the ground rebound.
We presented cyclic consolidation characteristics of alluvial clay in a previous report 1).