Applied Mechanics and Materials Vols. 361-363

Abstract: Nowadays, uncertainty regarding the calculation method of effective length factor of high-pier has brought many inconveniences to the design of bridge. To solve the problem, this paper demonstrates the calculation method of effective length factor on the basis of Eulers formula considering both the influence of high-pier s dead weight and non-ideal boundary conditions on the critical force of first-order buckling. The influence of piers dead weight on effective length factor in the construction and finished stage are evaluated by numerical examples. Results show that: the effective length factor becomes smaller considering dead weight both in construction and finished stage. Moreover, high-piers dead weight causes more influence in the construction stage than finished stage which should be considered seriously in the design and construction.

Abstract: After the earthquake, rapid detection, assessment and emergency rob pass, the traffic is the important content and key link of rescue and relief work on the bridge earthquake damage suffered. The United States, Japan and China's Taiwan region is also a strong earthquake areas, due to the road traffic damage in earthquake, to these countries and regions for the seismic design of structures and strengthening technology, post-earthquake rapid assessment and development of traffic recovery technology. In our country, although the strong earthquakes occurred frequently, but as a result of the earthquake occurred in the remote, the population density of small area, so the lack of information about seismic influence on traffic roads, limits the development of related technology. Until the 1976 Tangshan earthquake, the earthquake caused complete paralysis of highway traffic, earthquake damage investigation on highway development of our country, for the subsequent revision of seismic design of highway engineering specification to play a role in promoting. The May 12, 2008 Wenchuan earthquake and April 14, 2010 Qinghai Yushu earthquake makes the traffic infrastructure severely damaged, resulting in post-earthquake relief work is blocked, delayed the rescue time, also exposed China's rapid detection of defects assessment and emergency maintenance repair technology technical reserves hidden dangers in post-earthquake highway bridge.

Abstract: A steel-prestressed concrete composite continuous beam bridge is one of new type navigational bridge structures with economic and clear mechanic behaviors. The junction of steel and concrete beam is the critical part, which makes the two different materials to be continuous structural system and transfer different kinds of loads reasonably. This article takes the Chang Bridge which locates on G318 state road in Changxing County, Zhejiang Province as the background to analyze the characteristics of transferring bending moment in the junction by the finite element method. The results show that the junction of steel and concrete designed can transfer loads smoothly. Therefore, the junction can be further researched for extensive application.

Abstract: For the problem of not complete filling the ducts with grout that frequent appearances in construction, the paper carried out the grouting compactness experiment of prestressed duct with kinds of grout materials produced by domestic manufacturers combining with different grouting techniques. The results indicated that all grout materials had bleed water. The ducts in test girder could not be completely filled. The vacuum-aided grouting technique’s grout bleed water is smaller than that of ordinary grouting technique, but still not be perfect. For this, the grout compacting device with independent intellectual property right is an effective measure.

Abstract: Taking use of SolidWorks and ANSYS Workbench FEM software to establish numerical analysis model and using the node mapping and sectional integral method for the calculation of three-dimensional solid model of bending moment, this paper puts forward a negative moment optimal formula. The optimal formula including parameters λ when took into account the different supporting patterns for continuous box beam bridges. With the comparative analysis of CODE(JTG D62-2004) method and measured data, it draws a conclusion that considering the support patterns on pier top negative moment influence on engineering structural analysis is more appropriate.

Abstract: According to the seismic performance of cable-stayed bridge with a project example, using finite element analysis method, establishing the space beam element and link element calculation model, the dynamic characteristic and the seismic response of the cable-stayed bridge with selected three earthquake waves were calculated, the results were compared with the of the response spectrum method.The results show that:the semi-floating system of cable-stayed bridge is great flexibility, the vibration cycle is generally longer; the results by using the response spectrum method are smaller; the cable-stayed bridge should be calculated in accordance with the specific circumstances of the project with multiple seismic waves.

Abstract: Songhua River Bridge is an important large concrete bridge engineering in China. Because it is located in complex environment, the reinforcing steel rust, freeze-thaw, artificial damage and washout will result in performance degradation of the concrete structure. The paper firstly invested the climatic environment and local corrosion environment. Then, according to the environment characters, studied the structure endurance degradation regulation combining the laboratory simulation tests and natural exposive tests. Made a group of concrete test specimens according to the true construction field material mixture ratio. The field experiments include air exposure, half soaking and full soaking tests. And the laboratory tests include freeze-thaw test, salt aspic test, chloride ion penetrant test, carbonization test, etc. Through test research, the paper gripped the degradation regulation of bridge concrete property. Then constructed the bridge concrete endurance degradation model, established the theoretical foundation for predict the large bridge service life.

Abstract: As the object to continuous girder bridges of movable formwork construction,for the same real bridge according to the new code and old code respectively establish finite element mode and for the corresponding calculation and checked, through the comparative analysis about construct materials, calculation conditions and the calculation results, etc,to discuss the difference of the design results between the new standard and the old standard, in order to accumulated useful experience about designing new bridge and reinforcing and reforming old bridge.

Abstract: A large number of design, construction and maintenance measures may be selected by bridge engineers to help ensure safe and durable service. In the present paper an improved model is developed for time-dependent reliability estimation of RC bridge decks subject to general and localized corrosion. The preliminary model developed is improved by considering weakening of the bond interface between concrete and reinforcement as a result of reinforcement corrosion and serviceability limit states in the time-dependent reliability analysis. A probabilistic model is developed that relates loss of reinforcement area to a non-linear bond stressstrain relationship.

Abstract: As the object to a prestressed concrete continuous girder bridge, which is an actual bridge, finite element modes were established respectively for the same actual bridge in different construction methods. The calculation results were analyzed comparatively and then the difference of the design results between the two construction methods was discussed in the gravity of structures, combination for action effects and the reinforcement bars, in order to accumulate useful experience in designing bridges.