AbstractSemi-integral abutment bridges are integral abutment bridges with a flexible interface at the abutment to reduce the force transferred to the foundation. Past research has investigated the uplift forces from the drill shafts using finite-element analysis, while insufficient experimental data exist to validate this hypothesis. Therefore, a semi-integral abutment bridge in Ohio supported on drilled shafts was monitored for a long-term to investigate the performance of semi-integral abutment with drilled shafts and abutment walls under environmental conditions. During the construction of the bridge, vibrating wire strain gauges were placed in three drilled shafts, footing, and the abutment wall above. Strain and temperature were collected from the installed sensors. It was found that the seasonal and daily temperature changes significantly affect the changes in the strain in the substructure. The behavior of the abutment wall significantly affects the behavior of the footing and drilled shafts. The behavior of the abutment was irreversible, and the top of the abutment wall and the top of the drilled shaft induced higher strain than the bottom. Cracks were noticed at the front face of the abutment wall, and the extremely cold weather conditions induced tensile strain higher than the allowable strain at the top corner of the front face of the abutment wall. In addition, a three-dimensional finite-element model was created and calibrated with the field data. The FEM results were used to investigate the maximum stress magnitudes and locations under temperature variation.