Applied Mechanics and Materials Vols. 178-181

Abstract: The 4th Nanjing Yangtze River Bridge North Terminal Chuhe Bridge is a prestressed concrete composite box-girder bridge with corrugated steel webs constructed by cast-in-place cantilever method. In order to shorten the construction period, it takes the closure scheme which is under asymmetric constraint. In this paper the force and stress in each important construction stage under different closure schemes were analyzed. The results showed that the procedure of the closure method under asymmetric constraint is feasible.

Abstract: As one of the important traffic facilities in cities, reinforced concrete bridges provide necessary services for the traffic in cities, but bridges that have been built in cities do not meet the requirements in durability aspect. We conduct a study about the durability of urban concrete bridges in Hebei province by this paper,analyse influencing factors of the durability of urban reinforced concrete bridges,provide measures and suggestions for the design and construction of bridges.

Abstract: A load test on a multigirder concrete bridge of 25m Span having a noncomposite deck slab is described. The bridge was designed to have eight simple supported spans, each consisting of a cross section with six RC T beam. Through analyzing the static and dynamic character of bridge structures, calculating efficiency ratio of load test, pickign up the results of observation points, it was determined that the girders were acting non-compositely with the concrete deck and that significant restraint was being developed at the bearing supports. Results of analyses conducted using the numerical model were compared to the measured response and found to be quite similar. By comparing the various load ratings, and by considering the nature of the unintended composite action and support restraint, decisions regarding the determination of a safe bridge rating are discussed.

Abstract: In this paper, one certain space under bridge which was used as a storehouse has been simulated numerically. The flow was considered turbulent and buoyant. A simple geometry was adopted, consisting of a room with a door that plays the role of inlet and another of outlet for the air. Four bundles of wood burners which considered as a volumetric heat source were placed evenly in the space. The problem was simulated by using the RNG K-ε turbulence model, modified to account for buoyancy effects. Several useful results were obtained.

Abstract: In order to study the prestress loss of the periodical temperature stress on the structure, this test has carried out the temperature stress analysis of 4-piece prestressed rectangular columns. The test takes Baiguodu Bridge in Chongqing Municipality as the supporting engineering to simulate the continuous effect of annual temperature change, for the measurement of prestress loss of the concrete structure. The study has shown that: prestress loss from periodical temperature change exists, and in the present, the design has insufficient estimation on this loss.

Abstract: Bridge is a kind of structure that is common in our daily life, it connect both sides of rivers, lakes, and even channels, also sometimes it is used to solve transportation problem, just like overpasses. Cable-Stayed Bridge because of its special advantages (large-span with fewer piers) is playing an increasingly important role now. In this work we made some research on structure design of Cable-Stayed Bridge, static analysis, dynamic analysis and Construction of the structure was proposed.

Abstract: Freight transportation activities in the present circumstances are closely related to a larger context of logistics decision-making, but logistic requirement is not relevant to all types of goods. Most existing freight transport demand models used for mode and route selection still focus only on the direct factors. This paper discusses the taxonomy of logistic and transport models, and the factors can be incorporated into freight transport demand models in order to improve the forecasting capability of the model.

Abstract: This paper presents an investigation of the effects of rainfall with varying precipitation intensity at every millimeter interval on urban freeway free-flow speeds. The traffic data and corresponding weather information data from the Inner Ring in Shanghai for more than one year were used. Statistical and regression analysis were applied to investigate the effects quantitatively. There are three major contributions of this paper. Firstly, statistical analysis indicates that the rainfall does not significantly affect the speeds variability until the flow rate reaches to a certain level, such as 400veh/h/ln in this study. Secondly, the variation pattern of mean speeds at every millimeter interval of precipitation intensity was investigated. Thirdly, it is the first study to model the effects of precipitation intensity at every millimeter interval on free-flow speeds. Both piecewise linear model and natural logarithm model were used to model the effects of precipitation intensity. By comparing the two models, the piecewise linear model is proposed in this study.

Abstract: This paper analyzed the expressive form and the formation principle of driver’s visual rhythm in the process of driving. Combined with the design model for speed control in straight line section, it proposed the design theory for speed control for long stretches of freeway by using the feature of visual rhythm. Using the 3Ds MAX, the video simulating car moving process on the long stretches of freeway was made in which visual rhythm was a key manipulative parameter. The SSES (Stimulation of Subjectively Equal Speed) was the index of this simulation experiment. Seven males and three females took part in the experiments. The demonstration experiment indicated that the design theory based on visual rhythm can ensure participants regularly maintain a high SSES.

Abstract: The primary objective of this paper is to provide a comprehensive overview of state-of-the-art and state-of-the practice of ATCSs. The review focuses on the following major aspects: (1) commonly deployed ATCSs in the U.S. and other countries; (2) features and functions of different ATCSs; and (3) evaluation studies based on field tests or laboratory simulation. According to the published literature, the majority of system deployments resulted in significantly improved traffic operations compared to traditional time-of-day coordination plans. Besides, based on the number of system deployments, SCOOT has the largest world-wide deployments, while SCATS has the largest U.S. deployments. Considering the costs of the deployment, ACS Lite was the lowest, while SCOOT was the highest.