RESEARCH ON DEFORMATION OF FRAME STRUCTURES IN UNDERGROUNDWORKING-OUT SECTION AREA

The D- P criterion is adopted as a constitutive relation of a foundation.The quadrangle element and beam element are also used.The effect of the distance away from buildings, the depth, the height and overburden in working-out section area is studied using FEM.The simplified stiffness matrix method considering the second matrix is used to calculate deformation, location and sequence of plastic hinges.The result shows that the working-out section area affects the frame structure greatly in a certain distance.When shear stress of column increases, the sequence of plastic hinge changes.The ductility of the structures changes into poor one.The result also shows the strip foundation is advantageous over the independence foundation.At last, some structure measures are suggested to protect the frame buildings.