The Rearsch Of Reinforcing And Strengthening Single Box-ribbed Arch Deck-Bridge

Among those in service series bridges in China, As one kind of ancient bridges, the arch bridges are becoming one of the most popular useful and competitive bridges .Because it can surmount longer, bear more heavy vehicles, the arch bridge's constructing fee and the maintaining fee is very less. Along with our economy's high speed development, the vehicles' quantity sharp grow faster, the vehicles' weight are increasing, the vehicle's speed are improving, and the vehicles set a higher requestion to the capacity of bridges. Those bridges built before the 1980s , for the lowly design load standard, and having been used for almost 30-40 years, these bridges can't make the need of the fast develop economy and begin to ill . Gradually entered the service time, but those bridge still have to serve in a long time, these bridges are giving a more important and trouble topics to the general highway administration.The Qinfeng bridge is seated on one county road of Shaoxing city, the superstructure of Mainspan is 2 decks types single box-ribbed arch bridge. Just like other bridges built in 1980s, the arch bridge was designed as the steam -15 load rank construction, when The bridge has served almost for 30 years, for all sorts of reasons it began to appear a more serious disease, and reached to the bridge service the peak. The disease of Qinfeng bridge started to affect the traffic safety, So Shaoxing highway administration decided to reinforce the bridge.In the process of reinforcing the bridge, we have carried the engineering research on raising the Steam -15 load standard rank to Steam -20 level, and strengthening of arch bridge structure. This paper depends on the Qinfeng bridge's strengthening project ,We carried the examination of the bridge's technology condition, used the finite element analytic method to calculate the stress analysis of main arch ring structure and analysis the supporting capacity.According to the design mentality as "saving, practical, reasonable, economical and feasible", we proposed to strengthen and reuse the original bridge, not to demote the old bridge. Meanwhile We pointed to enhance the load rank to the steam -20 level, and to display arched bridge potential, And formulate the construction flow,reinforcement craft and construction main point of strengthening the main span and the dry bridge serviced.When the strengthening project completed, the load experiment was carried to test the effect of reinforces and the supporting capacity, Finally through the later period observation analysis to test the anticipated effect. The research showed the Qingfeng bridge' reinforcing have raised carries the work to obtain the anticipated effect, have saved the massive constructions fund, also have obtained the better social efficiency.Through Qingfeng bridge's strengthening research, it proves that we can excavates the existing old bridge through the reinforcement the potential, and extends the elder bridge the service time and the life , it can let the old bridge adapt the steam -20 level.. That is possible and realizable. It will save massive constructions fund, and obtain the better social efficiency. The research results has a more important instruction and themodel significance to the similar bridge service.