Advanced Materials Research Vols. 374-377

Abstract: In ethical perspective a city is not only for residence, but also is the carrier of its culture, which is especially true of a famous historical city. In the process of urbanization, most larger and major Chinese cities have not appeared in the world heritage list by UNESCO. In order to change the disconcerting situation, this article focuses on the dignity of the historical city and proposes three measures, after analyzing the basic causes. In conclusion, constructing the dignity of Chinese historical cities is the key to resolve the problems in protection.

Abstract: Steel structure dam, as a newborn dam type in hydropower engineering field, is proposed in this paper. The conception, operating mechanism, bar concection and the design and calculation methods are introduced. The characteristics of the steel braced frame that overall force and stability are fully utilized, and also the steel properties, such as high strength, high tenacity and high wearing. As a new technique and method, it opens up a new way for the application of rich steel resources in the hydropower engineering, which shows a good development prospects.

Abstract: This paper introduces durability design method of tunnel lining structures based on approximate probability. According to the method, the corresponding application program, named tunnel lining structures durability design program (TLSDDP), has been developed, which can be used in the similar tunnel lining structures durability design in the future. TLSDDP was applied in Shanghai Yangtze River Tunnel lining structures durability design and the tunnel durability design limit state equation was obtained.

Abstract: Some rock slides have taken place in Three Gorges Reservoir Area, China. Many Researches on the causes of the slides shows that the more sensitive of rock strength to the reservoir water level fluctuation, the easier to fail of the rock slopes. In order to study the strength difference of different sandstones in reservoir water fluctuation zone of Three Gorges Reservoir, the authors taken two types of sandstones with different composition of minerals as a typical case to study in detail. One type of the two sandstones (called Type I) is composed of quartz, feldspar, muscovite and calcite, argillaceous cement. The other (called Type II) is composed of quartz, feldspar, sericite, argillaceous cement. Uniaxial compression tests indicate that the compressive strength of type I sandstone decreased significantly as they underwent first wet and dry cycle, and then nearly kept constant when they underwent the following wet and dry cycles, and that the compressive strength of Type II sandstones nearly kept constant when they underwent many times of wet and dry cycles.

Abstract: As for structural beam of travelling bridge under reciprocate loads, at the bearing there will be a large change in stress of structure, while at the ends and midspan, the change of stress of structure will be simple. In this paper, based on the bearing features of travelling bridge structure, as well as features of steel-truss beam and steel box beam, a new composite structure, which is named as steel truss-steel truss box beam, is put forward. This new structure adopts steel box beam with truss inside at the bearings, and adopts steel truss beam at the midspan. Based on a certain engineering project, combined with ANSYS, according to a serious of sizes and structure styles, work of modeling, analysing and optimizing has been done in this paper. As calculating results showed, steel truss-steel truss box beam not only has higher bearing capacity, structural bearing capacity and a better wholeness, but also has a lower steel usage, which can provide references for similar composite structures' research in future.

Abstract: The interface fracture process of most layered or bonded structures is commonly under the control of mixed mode cracking where the interface shear and normal fracture components exist simultaneously when the hybrid joints are bonded with different adherend materials. In this work, a simple and novel method is proposed to realize and characterize the pure mode I interface fracture for the hybrid joints with dissimilar substrates. The theoretical and experimental results indicate that the present method may be considered as a standard test method for the characterization of hybrid joints with dissimilar materials.

Abstract: Based on an engineering example of intrusion-clearance of diaphragm wall, the mechanism and effect factors of intrusion-clearance are discussed by monitoring data and numerical analysis. The research result shows that the deviation of diaphragm wall, bad quality of improved soil and insufficient outward-moving of diaphragm wall cooperatively lead to intrusion-clearance, and the first has a significant effect. Moreover, dewatering of foundation pit also cause deformation of diaphragm wall, which accounts for more than 25% of the deformation during excavation, but usually despised in construction. The improving effect of reinforced soil attributes more to the deformation of diaphragm wall, especially the area closed to diaphragm wall. Some remedies and precautions are also given in this article, which could provide references of design and construction for similar projects.

Abstract: Based on appropriate numerical constitutive model of lightweight aggregate concrete filled steel tubes (LCFST), layered method was adopted to predict the complete moment-curvature curves of LCFST composite section subjected to pure bending. A FORTRAN program for the moment-curvature curves was developed. Applying the layered method, the influences of the significant parameters, such as steel ratio, yield strength of steel and strength of lightweight aggregate concrete on the moment-curvature curves of the composite section subjected to pure bending were discussed. The practical composite flexural stiffness, ultimate moment and practical moment- curvature relationship of LCFST composite section were presented. The predicted results of both layered method and practical moment-curvature relationships of LCFST composite section are in good agreement with the test results from reference. Compared with the layered method, practical calculate method could remove the step of composite section layered and improve the calculation speed while achieving similar results.

Abstract: In some areas with high intensity and near the epicenter, the buildings, especially nuclear power station, lifeline, long-span structures, information and other important buildings, are of obvious vertical earthquake component by the effect of macroseism. So the research on three dimensional shock insulation including vertical earthquake component should be conducted. The horizontal isolation which is widely used for vertical seismic isolation effect is not obvious and its application in practice is limited highly. Considering its defects mentioned, this paper studies the SMA-disc spring three-dimensional composite bearing from the perspectives of mechanical parameters, performance, structure and working principle and applies it to the typical spatial reticulated structure. By comparison, it can get a conclusion that SMA-disc spring three-dimensional composite bearing has better three-dimensional isolation effect.

Abstract: In this work, a method to simulate Stochastic Fields of Corrosion Pit Depth of corrosive steel structure by Cosine Trigonometric Series Model is presented. Moreover, a mathematical proof of Stationarity and Ergodicity of mean and auto-correlation function is given.