Study on the deflection of early-strength splice joints in widened bridges under vehicle loads

In bridge widening, traffic loads can cause different deformations in the new and existing structures, leading to splice joint cracking and reduced performance. This study investigates a simply supported T-beam bridge with an early-strength concrete splice joint. A finite element model in ABAQUS was built to analyze midspan deflection differences under various lane loads and splice joint moduli. The most unfavorable vehicle load position was identified. The study also evaluated traffic control and beam-type shear frames. Results show that closing the lane next to the splice joint reduces the existing bridge deflection by 78 %, and installing shear frames at the two one-third-span positions cuts the deflection difference by 85 %.