The shear failure characteristics and failure law of spread foundations are researched by tests on ten model foundations. The results show that punching shear failure of foundations will occur when the width of foundation is greater than the width of column plus double effective height h0 of the foundation. When the width of foundation is less or equal to the width of column plus double h0

shear failure will occur if only arranging bending reinforcement; and bending failure will occur if arranging reinforcement according to beam. The ductility and bearing capacity of strip footing under column will increase considerably comparing with raft foundations when the size of foundation and longitudinal reinforcements are identical. The arrangement of reinforcement of strip footing under column should design according to that of beams are suggested

so as to avoid brittle shear failure of foundations.