Advanced Materials Research Vols. 250-253

Abstract: Gravity dam foundation failure progress is always associated with its deformation development. So dam foundation deformation should be paid more attention in gravity dam stability analysis. Key node plays an important role in analyzing the dam foundation deformation development. But how to select key node is worth researching. A gravity dam foundation stability is studied by the development of plastic zone and key nodes’ displacements in dam foundation. The problem of key node selection is researched and a key node selection method is brought up also in this paper.

Abstract: The Theoretical calculation and the finite element method (FEM) are used for studying the thermal property of hollow-block and hollow-masonry. The method of appendix in the standard for Thermal Design of Civil Buildings is adopted to calculate the thermal resistance and the average thermal conductivity of hollow-block and hollow-masonry. ANSYS is used for simulating temperature distribution and heat flux law under connective loads. The conduction and convection phenomena are taking into account in this study for four different values of the mortar conductivity and four different values for the bricks. The thermal resistance and the average thermal conductivity of hollow-block and hollow-masonry is the key factor for reference.

Abstract: Anthropogenic heat released from air conditioning systems is one of the most important factors contributing to the heat island in summer. A model to predicted heat island intensity is built. Using this model, a typical office building cluster is simulated, and the effect of heat released by air condition on outdoor thermal environment and heat island intensity is discussed. Furthermore, the reaction of heat island intensity rising on the performance of air conditioning systems is also investigated.

Abstract: Analyses the flow process of hot oil in the organic heat transfer material heater based on finite time thermodynamics for the first time, obtains the entropy production rate which includes entropy production rate of dissipation effect and entropy production rate of potential difference, analyses the influence of flow pattern, physical parameters, structure and operation of the organic heat transfer material heater on the entropy production rate of dissipation effect, illustrates the influence of related parameters including Renold number, velocity, viscosity and pipe diameter on the entropy production rate of dissipation effect, and points out the type of hot oil must be considered to decrease the entropy production rate of dissipation effect and the velocity must be control under the premise of avoiding overheat.

Abstract: This paper compares key performance indicators (KPI) for infrastructure sustainability in the United States and China. The paper also discusses the implications and challenges of addressing sustainability and sustainable development in the two countries. The research shows that there are noticeable differences in the indicator system structure, although there is general agreement on the concrete sub-indicators. These differences are closely linked to the research method, theory of the respective country and the macro-level priorities in formulating their sustainable development agenda. The America KPIs system was set up by Delphi method, while the Chinese one was based on complicated systematical theory and systematical ecology. The most significant agreements are on sub-indicators related to ecology, economy, project management and administration. However, there are significant disagreements on some indicators related to special indicators of highway systems. The contribution of this paper provided empirical evidence of such underlying differences. Based on the comparison of the two KPIs systems, further research is suggested to validate the indicators and the structure for infrastructure sustainability.

Abstract: Performance of the smoke exhaust system in two atria with nonuniform spaces will be analyzed by fire models in this paper. A two-layer zone model and a Computational Fluid Dynamics field model FDS developed by the Building and Fire Research Laboratory, National Institute of Standards and Technology, USA are used. Numerical results are compared with the experimental data by hot smoke test in these two atria. Both fire models can give good predictions and so are suitable for evaluating the performance of the smoke exhaust system.

Abstract: Review both domestic and overseas pedestrian flow characteristic research results. Enumerate our country’s research achievements recent years. Introduce that the domestic scholars draw the pedestrian speed characteristic and pedestrian flow model according to different time, place, environment and other cases. Examples show that the pedestrian speed characteristic and pedestrian flow model has certain differences. For example, most domestic scholars describe speed - density relational expression with dynamics model, logarithmic model and linear model. This paper proposes that establishes reliability index for different pedestrian flow model, studies how different facilities affect the pedestrian flow characteristics, and establishes data reference standard for pedestrian flow characteristic.

Abstract: Night ventilation has been proved to be an effective cooling method, especially in regions with a large temperature difference between day and night. The main work of this paper is to analyze the parameters associated with ventilation effects in office buildings with night ventilation in the city of Xi'an. For this purpose, field investigation about different kinds of office buildings has been carried out, based on which, a typical office building simulation model has been built. Three parameters, including temperature difference between day and night, thermal storage performance and air change rate are studied by the energy simulation software DeST and the optimum values have been proposed for each parameter. The conclusions can be useful in night ventilation design process.

Abstract: Connection the upper components and disconnection the other components is widely used in the expressway hollow slab bridge widening and reconstruction. How to design the transverse joint between newly-built and existing bridges is a key problem in the renovation of prestressed concrete bridges. In this paper, combined with a freeway widening project, 2 kinds of different connection forms were compared by their transverse distribution influence lines, which were calculated by finite element method. The results show that the new and old bridges are working together after widening, which makes vehicle loads of the slabs of the old bridge are reduced, especially the side slab of old bride which was next to the slab of newly-built bridge dropped by nearly 50%. So the bridge widening strengthens the safety of old bridge. And the weak connection of the bridge is always the connection of newly-built bridge and existing bridge, which is accorded with practical situation. So the particular attention should be given to the connection. It provides a basis for widening the old bridge and a reference for widening and maintenance the same kind of bridges.

Abstract: In order to protect natural environment and save construction cost, both the physical and mechanical properties and the strength change laws of stabilized sandy soil mixture were studied in this paper based on the characteristic of sandy soil stabilized by Lufeng-1 soil stabilizer. The results show that the pavement performance indexes of the sandy soil stabilized by soil stabilizer completely meet the design requirements of every pavement structure layer below base in certain proportion and the optimum proportions for pavement roadbed, sub-base and base materials also are recommended, which provide technological foundation for the utilization of sandy soil.