STRUCTURAL-ANALYSIS MODEL FOR MAT FOUNDATIONS

A simplified structural analysis model for mat foundations with grid f loor beams as stiffeners is presented here. In the model, the Winkler type of subgrade reaction spring is assumed for the whole area under t he mar foundation, and the yield-line theory of slab is used to lump t he Winkler springs under slabs to the corresponding locations under th e adjacent floor beams of the slabs. Therefore, each floor beam is now supported by springs with a segmentally linearly varied spring consta nt. The total analysis model for the mat foundation is then simplified to be a grid beam system on an elastic foundation with a segmentally linearly varied spring constant, and is subjected to loadings from the columns of the building structure. Some numerical comparisons with th e results by a sophisticated finite-element model are made in order to demonstrate the effectiveness and efficiency of the presented analysi s model.