Bridge construction with continuous deck and integral abutments eliminates the need for expansion joints and bearings resulting in better durability and reduced maintenance costs. However with integral bridges, seasonal temperature variations are capable of inducing significant movements of the abutments through expansion and contraction of the deck. If this movement is not adequately accommodated, sliding or rocking of the abutment upon its foundation may result in soil yielding and reduced bearing capacity, particularly for clays. This report reviews available data on low frequency cyclic loading and discusses the implications on the design parameters appropriate to the foundation problem. The performance of cohesive soils in an integral bridge foundation is compared with the behaviour of granular soils. The review is supported by results from laboratory triaxial tests which simulate the cyclic loading regime in an integral bridge situation. (A)
Abstract