METHOD FOR CALCULATING PUNCHING SHEAR CAPACITY OF PRESTRESSED RAFT FOUNDATION UNDER BORDER COLUMN BASED ON STRESS DIFFUSION

摘要

Accurately calculating effectively horizontal prepressed compressive stress is crucial for designing punching shear capacity of the raft foundation under a border column. Theoretical solution with a full considersion about stress diffusion of total horizontal prepressed compressive stress is gained using Fourier expansion to deal with concentrated load. Farther effectively horizontal prepressed compressive stress is computed in terms of stress diffusion method and modified coefficient method. Calculating results show that the punching strength considering stress diffusion is higher than that without considering, which confirms the conservative of design method for punching shearing capacity in the specifications by China. A formula is proposed for computing punching shearing capacity of the raft foundation under a border column, which can be taken as a referrence for designers and builders of construction project.