Research About Construction Monitoring Technology Of Long-span Tie-bar Arch Bridge

Under the background of Nanhe bridge on expressway of Nanjing to Hangzhou, this paper researches about monitoring mechnology of long-span concrete-filled streel pipe arch bridge.In order to monitoring concrete stress in tie-bar of long-span concrete-filled streel pipe arch bridge, mothod of separate tension is used, which deducts tension caused by temperature changeand creep. It is testified that this mothod is feasible and the precision is satisfyed. When tie-bar is constructed by several segments, it is difficult that keep pipe smooth and the value of k is bigger than normal. It is necessary that doing tension experimentation of prestress cable. On the base of vibration formula of cable, the influence of boundary condition and bend rigidness to testing soften cable tension force deeply reserached. A mothod of testing soften cable tension force is adviced. If the first frequency of cable is tested, it is easy that calculating its tension force. Finity element method proves this mothod is reliable. A mothod is introudced to recognise length and bend rigidness of cable. The problem of how confirm bend rigidness of cable is settled.In order to settle initialize tension of cable, zero-displacement mothod, rigid-support continuous beam mothod and the least-energy mothod is used respective at Nanhe bridge. It is found that zero-displacement mothod can not be used in concrete-filled streel pipe arch bridge. When bend rigidness of tie-bar and bend rigidness of arch is almost same, rigid-support continuous beam mothod and the least-energy mothod without restriction formula is satisfactory. But the least-energy mothod without restriction formula is better then rigid-support continuous beam mothod. When bend rigidness of tie-bar is less then bend rigidness of arch, rigid-support continuous beam mothod and the least-energy mothod without restriction formula is not useful. The least-energy mothod with restriction formula is adviced.