Applied Mechanics and Materials Vols. 90-93

Abstract: A new type of cable-stayed bridge, single pylon cable-stayed bridge without backstays is used in the Zhenshui Road Bridge in Xinmi City, China’s Henan Province, which adopts PC box girder with corrugated steel webs. It has many advantages such as light girder deadweight, low pylon height and avoiding webs longitudinal cracks. This novel bridge is adopted firstly in China. Cast-in-place method with bracket is used in the construction of the bridge’s inclined pylon because of its complex construction technology and tight construction period. In this paper, interests are focus on the scheme comparison and selection of bracket construction, the establishment of bracket’s computational model and the result of numeric analysis etc. The chief aim of this investigation was provides useful reference and enlightenment to similar bridge types.

Abstract: Load-carrying capacity evaluation method of existing pre-stressed concrete hollow slab is represented based on the example, inspection content, method and result are introduced. Based on the result, carrying capacity condition is evaluated by the relevant code. The result can validate the rationality and effectivity of the method, which is useful for the carrying capacity evaluation of similar structure.

Abstract: This paper shows the stability of cable-stayed bridge under floating system. A large-span prestressed concrete cable-stayed bridge in Chongqing is analyzed by using nonlinear finite element program ANSYS. The buckling mode and linear and nonlinear stability safety factor of the bridge under two unfavourable live loads are gained and compared by numerical simulations. The results show: 1) only in-plane instability is induced regardless of the loads；2) Under the floating structure system, nonlinear stability safety factors of the bridge under two unfavourable live loads do not meet the specification requirement four, but they are actually bearing capacity stability factors, and should be said adequate safe when they can reach about three. Limit value on nonlinear stability safety factor of the bridge does not provide at present, but we believe that in general about three should be able to meet the requirement through the practice of some of the previous bridge

Abstract: It is necessary to evaluate the flood control impact of a river-crossing bridge . Aiming at the problems exited in the evaluation,the analysis and discussion on the procedures,methods contents and related issues of the evaluation are made here by taking a bridge over branches of the XiaoheRiver for example.At the same time,the feasible engineering measures are proposed for building of the bridge,which will be applied to similar projects in the future.

Abstract: Abstract. The experimental research on heavy haul railway existent diseases under double disadvantage fatigue load of special high stress level and multiple cycle index in da-qin railway, the bearing capacity of existing slab culverts are calculated and analyzed on ultimate limit state and serviceability limit state. According to 1:1 scale,laboratory test study on cover plate’s deflection, crack, strain of tensile steel about one piece of slab culvert in different static load and assess the cover plate’s initial state maximum carrying capacity;and for the other two pieces of cover plates, static load below 30t compression was applied until concrete cracking in order to carry on fatigue test for simulating axle load in heavy haul railway, to detect the bearing capacity of the plate and assess the service life of slab culvert. It puts forward some suggestions for the further research field in slab culvert and provides a theoretical support and practical experience for present situation and service life on existing heavy haul railway.

Abstract: Cover concrete quality is very important for marine structures, which determines the beginning time of reinforcement corrosion and the life of the structure. The very early age continuous moisture keeping is essential for cover concrete properties develop; otherwise the long-term performance will be reduced heavily. There are many moisture keeping curing methods, but the drawbacks of traditional curing methods make them confined to use in marine environment concrete structures. A kind of moisture keeping membrane which can absorb and hold 100～5000 times of dead-weight water, and impede water evaporating outside with polyethylene film. The results of mercury intrusion porosimetry test and scanning electron microscope show that the new curing product can improve the concrete density decrease the connection degree of pores and the quantity of harmful pores content. Compared with other product on sales, the wet-keeping time can be adjusted and can be used repeatedly and continuously are the distinguishing features, which make it popular in some marine projects.

Abstract: In order to investigate the development of vehicle loads on highway in recent years，data collection and statistical analysis of vehicle loads in overload non-controlling area were made．It is shown that all ti1e vehicle loads follow multiple-peaked distribution．The vehicle load probability distribution in overload non-controlling area was simulated using a weighted sum of 4 normal distributions．In order to describe the load limit of heavy duty vehicle for bridge safety accurately，the vehicle load probability distribution in overload non-controlling area was simulated by a piecewise function．The maximum probability distribution of vehicle loads during different periods were simulated by the distribution of I type extremum．

Abstract: The life of concrete structure located in complex environment depends largely on the durability of concrete. The various environmental corrosive effects are the key factor to reduce the durability of concrete structures. The studies on corrosion mechanism and detecting/monitoring technology are carried out in the world, and achieved important results. Since the 90's of last century, corrosion monitoring system for concrete structure has been put into engineering practice in the world, and the technology has been being mature. Qingdao Bay Bridge is located in the special marine environment, so corrosion is the main factor affecting the durability of the bridge. Durability monitoring is one of important aspects of the structure health monitoring and maintenance management system of the Bay Bridge. By corrosion monitoring, the critical data of concrete durability and strength degradation of the structure can be obtained. It is very significant for understanding the evolvement law of the durability, developing anti-corrosion measures, and extending the life of the bridge.

Abstract: In this paper dynamic behavior of the Ying Zhou main bridge in Luoyang is studied .The finite element analysis software ANSYS is adopted to set up three-dimensional finite element model of a CFT arch bridge of the main bridge .The natural periods and modes of the CFT arch bridge are calculated by using the subspace iteration method. Meanwhile its modal characteristics are analyzed. Some useful conclusions are got by the calculation and analysis of the bridge for the engineering construction.

Abstract: In order to understand the mechanical characteristics of shenqiu Zhidian Bridge considering the influence of pavement, On the basis of installing steel mesh in rigid bridge or consecution to enhance the bonding performance between the pavement and girder, the load test is conducted. According to the test result and the calculations result the bearing capacity and work performance of bridge are evaluated. The results show that in the design of bridge, by enhancing the bonding performance between the pavement and girder, considering the overlaid pavement participating in force corresponds with the actual stress structure.