Numerical Studies on the Bearing Capacity of Two Interfering Strip Footings Based on HOEK–Brown Materials

"Current studies of bearing capacity for shallow foundations tend to rely on the hypothesis of an isolated footing. In practice a footing is never isolated; it is mostly in interaction with other footings. This paper focuses on a numerical study to evaluate the ultimate bearing capacity for two interfering strip footings resting on a rock mass in which the strength can be described by the generalised Hoek–Brown failure criterion. This criterion is applicable to intact rock or heavily jointed rock masses that can be considered homogeneous and isotropic.The material is assumed to exhibit perfect plasticity and obeys an associated flow rule. The effects of Hoek–Brown parameters including GSI, mi, and sci were studied and the corresponding results are presented. For different clear spacing (S) between the footings, values of the efficiency factor (?) were determined; where ? is defined as the ratio of the failure load for an interfering new footing of a given width (B) to that of a single isolated footing having the same width. The maximum value of (?) occurs at spaced between S/B = 0.5 to 1.0. The results have been compared with those available in the literature.INTRODUCTIONEvaluating the ultimate bearing capacity of rock masses is essential for important projects like dams and bridges. Closely spaced footings may occur on rock masses in the form of pier foundation and grillage footing. Close spacing lead to permit higher loads than can be bore by similar isolated footings. The ultimate bearing capacity of two interfering strip footings resting on cohesionless soil have been studied theoretically (Kumar, & Gosh, 2007; Kumar, & Kouzer, 2008; Stuart, 1962). Results revealed when two strip footings approached closely enough, failure zones affect each other and ultimate bearing capacity significantly increased."