Detection And Repair And Renovation Of Technology Zhongmou Qingyuan County Guanghui Street Bridge

With the rapid increase of transportation in China in recent years, lots of previous roads and bridges cannot meet the demands of communication and transport. Among them, the bridges constructed in early years have gradually become dangerous due to the low design standards, inadequate maintenance and conservation, and excessive operation. In long term operation, the multiple inevitable structural damage of the bridge causing serious hidden troubles. The dangerous risk also be aggravated by the change of environment, increase of traffic density and heavy vechicles, which promoting the irreversible decrease of bridge bearing capacity and durability. Overall, the prevalent dangerous bridge seriously limited the development of transportation which must bring to society high attention.The Qingyuan Bridge of Guanghui street in Zhongmu county was studied in our work. Through the inspection of appearance we found that:cracks existed in driveway and top of pier, the concrete in anchorage zone had serious damage. The beam slab concrete was destroyed partially, the stirrup rust and expanded on the scratched bottom, the slab joint detached and seeped alkaline water. The problems such as partly or completely escapes and mild or severe cracks existed in support and bearing stone. In pier cap beam there were severe water seepage and heavy corrosive area of concrete. The cap beam had vertical cracks. The static load test indicated the measured lateral distribution coefficient of main point in the test bridge span heavily deviated from the theoretical value under 1-6 loads. Thus the lateral connection was poor and the hollow slab could not be stressed a whole. With working condition 7, the impact coefficient was above the theoretical value of 1.236 in the dynamic load teat, suggesting the impact coefficient increased under bad road condition. Furthermore, the damage of bridge was analyzed and the reinforcement scheme was exploited. Overall, the detection of bridge could assess the actual loading capacity of old bridge and provide effective basis for designing operation and maintenance scheme. This paper could also supply experience and help for similar projects in future.