Study On Coactions Of The Box Shape Arch Bridge And Arch Ring And Steel Arch In The Cast-in-place Deck Type Reinforced Concrete

Due to the reinforced concrete box arch bridge has the advantages of good integrity, uniform stress distribution, good stability and other characteristics, in the mountain, canyon and other arch bridge has been built in western mountain area widely popularized, main span is 100-150 m.From the constructing point of view, the traffic of mountainous area haven't developed well, large lifting equipment difficult to approach or access costs are too high, the hoisting construction has certain difficulty with cable, so the arching cast-in-place construction to become a better construction method. Arch with large span capacity, convenient assembly, material can be used repeatedly and is not affected by the floods, the construction period can meet the normal opening navigation requirements, so it is particularly suitable for mountain area arch bridge to use of construction. In the traditional design of arch, arch bear more than 70% of the weight of arch ring, which may lead to high cost of temporary facilities, the increase of the dosage of arch, which increases the construction cost and assembling difficulty.This article is to Zhengzhou Bridge expansion project as the basis, combined effects of arch and arch ring is studied, through the space model of the construction process were simulated and compared with the field measured data, the authors found that when using reasonable sub-ring scheme, the pre casting concrete arch can withstand itself weight above 40%, which will greatly reduce the arch the number, cost saving. Therefore, the research of stress analysis and optimization of construction technology of box shape arch bridge which use arch in the construction, is of great value for the future construction of box arch bridge.This article will be based on the research on Zhengzhou Bridge expansion project, carried out the following research work:? Through the large finite element software MIDAS/Civil to establish simulated calculation model of arch ring structure which accord with cast-in-place construction process, combined with the measured data of Zhengzhou Bridge, research of the combined effects of arch ring pouring in advance and arch, calculate the contribution degree of the combined effects of arch ring and arch on the whole.? Based on the project example, the adjustment of arch sub-ring scheme, compare the effects of distribution ratio of arch ring and arch load which use different construction technology.? Under the condition of ensuring the arch stress does not exceed the allowable value, through the reasonable scheme of sub-ring, and to investigate regular patterns of coactions of arch ring and arch along with their width changing, then fit a linear equation.? Using the principle of reflection of deformation stiffness, and relative stiffness is the important influence factors of two joint section share load, put forward that using the deformation to estimate the proportion of sharing the arch ring load combined effects of arch ring and arch.The research work of this article provides a practical, effective construction scheme for building the Zhengzhou Bridge expansion project. At the same time, based on the above summary of the work, provide a reference for the same type bridge construction methods, have certain reference significance.