Abstract: There have been accidents of bridge floor system collapse due to hanger fracture occur in half-through and through arch bridges from time to time. Hence, current researches have mainly focused on the design of hangers. In order to analyze the robustness of suspended floor systems in half-through and through arch bridges, a scale test model of a half through bridge and a through arch bridge is established. The dynamic response of the bridge deck structures which have setting the stiffening girder after cables losing was tested. The test results are as follows. The initial tensile forces in hangers have effects on their fracture patterns and time to break. The less time to break the hangers increases the dynamic response of the system due to the hanger break. The system dynamic response with the fracture of longer hanger is larger than that with the fracture of shorter hanger. The most unfavorable stress sections due to the static effects produced by broken hangers includes the sections in broken hangers as well as the section of stiffening girder between two neighboring hangers. A finite element model is then established to test the feasibility of numerical simulation method for analyzing the dynamic response of broken cable by the experimental study of broken cable. The parameters of cable interruption time and damping ratio are proposed for numerical analysis.