Tolerable Settlement of Buildings

Current practices and concepts for establishing the tolerable settlement of buildings are reviewed. The role of differential settlement is emphasized. Most current tolerance limits are shown to be based on the works of Skempton, MacDonald, Polshin, and Tokar. These criteria are compared with field observations of settlement and damage. A simple beam analogy, which was proposed by Burland and Wroth, is used to illustrate factors that influence tolerable settlement. The effects of the critical tensile strain of the structural materials, the L/H ratio of the building, the relative stiffness of the structure in shear and bending, the longitudinal stiffness of the foundation, and the shape of the settlement pattern are demonstrated. Different criteria are required for different types of structures. The allowable settlement is smallest for cases in which the settlement curve is concave downward.