Developed three-dimensional dynamic analysis model to determine cause of severe vehicle-induced vibrations in Hillsborough River Bascule Bridge. Resolved vibration issue using several simple members. These findings have been used in many similar bascule bridges.

Developed new finite element method for analyzing elastoplastic buckling of trussed bridges that significantly reduces analysis time and resolves one of the most difficult bridge design and analytical issues at the time.

Developed three-dimensional dynamic analytical model to determine cause of severe vibrations in a type of concrete-filled steel tube bridge that was first developed in China. Found cause to be insufficient vertical stiffness of deck systems, and proposed improvements to resolve vibration issue.

Determined that in Prestressed Concrete U-Beam bridges, horizontal prestressing tendons will cause high vertical tensile force at the anchor zone which will increase with the girder height, leading to cracks in the end zones. Proposed design method currently being applied to bridge design. Proposed crack evaluation method that is applied to other bridge types, such as concrete segmental bridges and spliced I-girder bridges.

Determined that in Prestressed Concrete U-Beam bridges, horizontal prestressing tendons will cause high vertical tensile force at the anchor zone which will increase with the girder height, leading to cracks in the end zones. Proposed design method currently being applied to bridge design. Proposed crack evaluation method that is applied to other bridge types, such as concrete segmental bridges and spliced I-girder bridges.

Developed method for analyzing the moving vehicle and bridge contact issue as well as practical method for estimating the dynamic loading of arch bridges.

Develop methods for bridge ratings based on test results. This method provides more accurate load capacity rating, increasing load capacity and reducing unnecessary rehabilitation cost.

Developed new finite element method for analyzing straight and curved thin-wall box girder bridges. Proposed simple equations for predicating the dynamic loading for both straight and curved box girder bridges through field and theoretical analysis. These equations can provide more accurate bridge dynamic loadings and more economic bridge design.

Develop methods for bridge ratings based on test results. This method provides more accurate load capacity rating, increasing load capacity and reducing unnecessary rehabilitation cost.

Determined that in Prestressed Concrete U-Beam bridges, horizontal prestressing tendons will cause high vertical tensile force at the anchor zone which will increase with the girder height, leading to cracks in the end zones. Proposed design method currently being applied to bridge design. Proposed crack evaluation method that is applied to other bridge types, such as concrete segmental bridges and spliced I-girder bridges.

Developed three-dimensional dynamic analytical model to determine cause of severe vibrations in a type of concrete-filled steel tube bridge that was first developed in China. Found cause to be insufficient vertical stiffness of deck systems, and proposed improvements to resolve vibration issue.

Develop methods for bridge ratings based on test results. This method provides more accurate load capacity rating, increasing load capacity and reducing unnecessary rehabilitation cost.

Developed three-dimensional dynamic analytical model to determine cause of severe vibrations in a type of concrete-filled steel tube bridge that was first developed in China. Found cause to be insufficient vertical stiffness of deck systems, and proposed improvements to resolve vibration issue.

Developed new finite element method for analyzing straight and curved thin-wall box girder bridges. Proposed simple equations for predicating the dynamic loading for both straight and curved box girder bridges through field and theoretical analysis. These equations can provide more accurate bridge dynamic loadings and more economic bridge design.

First documented use of grid model in investigating bridge dynamic loading/impact factor due to moving vehicle, taking into consideration road surface roughness effect. Determined that heavier the loading, smaller the impact factor. Helped to explain long-observed, often significant, discrepancies between theoretical analysis and field testing.

Developed new finite element method for analyzing elastoplastic buckling of trussed bridges that significantly reduces analysis time and resolves one of the most difficult bridge design and analytical issues at the time.