Response monitoring and modeling of constructed light rail bridges

Light rail bridge is an important part of the public transportation system. The current light rail bridges are designed by the exist codes. However, codes are only specifying the design procedure of high way bridges, and they are lack of guidance for design rails and light rail train load. This research evaluated the constructed five light rail bridges in Denver, Colorado. The work includes testing and computer program modeling.;The testing part includes lab test and field test. A steel rail's strain is tested on lab my simulated light rail train with different types of boundary conditions. The steel rail on Auraria Campus Station and five working light rail bridges are tested on this research. The five tested bridges are the Indiana Bridge, Santa Fe Bridges, 6th Ave Bridge, Broadway Bridge, and County Line Bridge. The strain change on the steel rail which is applied the light rail load is collected on the Auraria Campus Station and five light rail bridges, and girder response of the five bridge also recorded on this project. The dynamic response of the five bridges is also monitored.;The models of the five light rail bridges are built on the computer modeling programs of SAP 2000 and CSI Bridge to analysis the static and dynamic response of the light rail wheel load. The analysis by modeling of steel rail break gaps cuts the steel rail by the length of 1, 2, and 3 inch respectively. The study also compares the dynamic load allowance (DLA) without and with rail break gaps in different length. Analysis of the thermal load on the light rail break is concluded on this research. It was shown that the current design code is conservative but acceptable used on the design of light rail bridge.