Behavior of a Stiff Clay behind Embedded Integral Abutments

Integral bridges can significantly reduce maintenance and repair costs compared with conventional bridges. However, uncertainties have arisen in the design as the soil experiences temperature-induced cyclic loading behind the abutments. This paper presents the results from an experimental program on the behavior of Atherfield clay, a stiff clay from the United Kingdom, behind embedded integral abutments. Specimens were subjected to the stress paths and levels of cyclic straining that a typical embedded integral abutment might impose on its retained soil. The results show that daily and annual temperature changes can cause significant horizontal stress variations behind such abutments. However, no buildup in lateral earth pressure with successive cycles was observed for this typical stiff clay, and the stress–strain behavior and stiffness behavior were not influenced by continued cycling. The implications of the results for integral abutment design are discussed.