Maximum length of integral bridges supported on steel H-piles driven in sand

This paper presents design recommendations for the maximum length of integral bridges built on sand. The maximum length limits for integral bridges is determined as a function of the ability of steel H-piles supporting the abutments to sustain thermal-induced cyclic lateral displacements and the flexural capacity of the abutment. First, steel H-pile sections that are capable of sustaining large inelastic deformations under monotonic loading are determined. Then, a low-cycle fatigue damage model is employed to determine the maximum cyclic deformations that such piles can sustain. Next, the nonlinear behavior of the piles and soil–bridge interaction effects are implemented in nonlinear structural models of two typical integral bridges. Static pushover analyses of these bridges are conducted to study the effect of various geometric, structural and geotechnical parameters on the performance of integral bridges subjected to uniform temperature variations. Using the pushover analyses results, design guidelines are developed to enhance and determine the maximum length of integral bridges. It is recommended that the maximum lengths of concrete integral bridges be limited to 190 m in cold climates and 240 m in moderate climates and that of steel integral bridges are limited to 100 m in cold climates and 160 m in moderate climates.