Analysis Of Effect Of The Differential Settlement On Force And Deformation Of Frame Structure

One of the primary reasons that engineering accidents are caused is the non-uniformity settlement of ground foundation. Damage of the non-uniformity settlement to building can't be ignored. There are many cases about big deformation,cracking,incline and collapse of building caused by non-uniformity settlement. Therefore, the effect of non-uniformity settlement on upper structure is a subject very worthy to be studied. This paper researches the effect of non-uniformity settlement on upper structure by using large-scale FEM software ANSYS.1.The interaction of plane frame and foundation under the symmetrical settlement is studied. This paper takes a four-story plane frame structure with two spans as an example. Theoretically approximate calculation of accessional internal force for plane frame structure under the symmetrical settlement is studied. And FEM solution is gained by applying FEM software ANSYS. Through analysis of theoretically approximate solution and FEM solution, it indicates that theoretically approximate solution is conservative in the condition of not considering the influence of axial deformation of column. After considering the influence of axial deformation of column, adjustment of internal force will reduce error between the two solutions.2.The effect of the non-uniformity settlement of ground foundation on the upper space frame structure is studied. This paper takes a four-story space frame structure with two spans as an example. The different pedestal for a body is installed at the joint of column footing, which respectively form the fixed support model and the elastic support model. Both integral plane settlement and basin-shaped settlement are applied in every model. Through analysis of the influence of two kinds of non-uniformity settlement, it indicates that the influence of the different settlement on the upper frame have a big difference. In the fixed support model, The beams are principally suffered with the bending moment and the columns principally suffered with axial force and moment under integral plane settlement. The beams are principally suffered with moment and shear force and the columns principally suffered with moment and axial force under basin-shaped settlement. In the elastic support model,the beams are suffered with shear force and moment and the columns are suffered with axial force and moment under integral plane settlement. The beams are suffered with shear force and moment but the differences among axial force,shear force and bending moment of the columns are very little. Under the same kind of settlements, internal force and deformation of frame structure in the fixed support model show more effects than the ones in the elastic support model. It indicates that design technique of the fixed support model is conservative and that design technique of the elastic support model has certain economy.