Advanced Materials Research Vols. 374-377

Abstract: Slope usually lies in an initial stress field, especially in complex three-dimensional stress conditions. When horizontal stress is larger than vertical stress or the two horizontal stresses are not the same, the horizontal in-situ stress has significant effect on the excavation slope stability. To investigate the effects of the original in-situ stresses, the strength reduction method is used to analyze three-dimensional excavation slope, and Mohr-Coulomb yield rule is adopted, the failure criterion based on analysis convergence is suggested. First, the horizontal stress is uniform based on the gravity load, when lateral pressure coefficient increases, the safety factor decreases, and the plastic zones develop from slope to foot foundation. Then the condition of lateral pressure coefficient change is analyzed, slope direction pressure coefficient increases, plastic zone on the slope bottom increases, the safety factor decreases remarkably. Using the same method to analyze that of the lateral pressure coefficient on the slope face direction increases, the slope FS increases little holding the K2 unchanged with the K1 adding. The results show that the slope direction pressure coefficient has more effects on the safety coefficient than that of the axis.

Abstract: This paper introduced the basic content of the habitat environment. Then, this paper analyzed the requirements and four core concepts in the Chinese “Home” dream. Based on these analyses, this paper proposed the key issues of Chinese habitat environment including the habitat pattern and problems for Chinese old urban people. Finally, this paper gives some suggestion in providing habitat environment for the Chinese elder people.

Abstract: The work presented in this paper focuses on durability of concrete bridges, which is worldwide concerned nowadays because concrete bridges will deteriorate and damage under the natural environment and the long-term usage. The shortage in bridges durability performance will result in severe environment problems; energy sources matters and economic issues. Quickly developed coastal cities and transportion, due to large-scale expansion of themselves and exploitation of ocean resource, have to face rigorous marine climate. Hence, the studies the authors have performed showed that as a civil engineer it is important to learn the research and countermeasure actuality on durability of coastal concrete bridges. According to current research, the existing problems as well as objectives for further studies are also indicated .

Abstract: The design and practice of a deep excavation in shanghai was presented. The FEM based on Mohr coulomb Model was adopted to analyze the deformation of the excavation and its effect on adjacent buildings. This method gives good prediction of both the deformation of the soil retaining structures and the settlement of the soils behind the wall after comparing with measured datas. Meanwhile, the method is suitable to deformation analysis of sensitive environment circumstance.

Abstract: For ductile beam-to-column connectiosn in steel frame, beam local buckling is difficult and very costly to repair in any post-disaster reconstruction. Shape memory alloys (SMAs) in their austenite states have the ability to recover their original shape after experiencing large deformations. Steel connections retrofitted using SMAs can be endowed with intelligent characteristics. This paper investigates extended end-plate connections using long shank SMA bolts. The SMA connection is designed using a new methodology of avoiding beam local buckling and adopting the strong end-plate. The connection deformations are supposed to concentrate on the SMA bolts. In order to study the seismic behaviour of the connections, quasi-static tests were conducted on both the SMA connection specimens. The test results indicate that the connection can show high deformation capacity with the maximum interstory drift angles beyond 0.02 rad. However, the beam was remained elastic during test and the deformations of the SMA connection were recoverable upon unloading. The load-drift hysteresis loops are flag-shaped for the SMA connection. This indicates that the connection has moderate energy dissipating capacity.

Abstract: The soil-structure interaction (SSI) effect is paid more and more attention in the dynamic structural analysis and earthquake resistance protection. However, theoretical analysis of SSI effect cannot accord with engineering applications because the analysis of SSI system is too complicated to be studied with a comprehensive theoretical basis. In order to promote the accuracy of dynamic analysis of SSI system in theory, in this paper, an analytical expression of motion equations of SSI system is given based on the concept of the continuity of dynamic system. In addition, mechanical models of SSI system on the basis of the continuity of motion domains are built and the analytical expression of equations of SSI system is given.

Abstract: From the point of strain energy, an important conclusion has been derived and proved that cable-strut structure stiffness will be enhanced with the increase of prestress, provided that the cable-strut structure is within the scope of linear elasticity, and external loads' work will be completely absorbed and transformed into structural strain energy.

Abstract: This paper first gives an introduction on the present study situation of urban group spatial structure evolution, then extracts the urban group spatial distribution information in Poyang Lake Ecological Economic Zone, and monitors in dynamic change of urban group spatial evolution from 1990 to 2009. Later, it analyzes the present situation and the reason of urban group spatial structure in Poyang Lake Ecological Economic Zone, and finally, presents some suggestion on how to over-all optimize and regulate the urban group spatial structure in Poyang Lake Ecological Economic Zone.

Abstract: In this paper, on the basis of the dynamic equation of material which contains transversely isotropic piezoelectric、piezomagnetic and elastic media, the state variables equation of piezoelectric、piezomagnetic and elastic circular plate in axial symmetric deformation is deduced. Under the given boundary conditions, according to the theorem of Caylay-Hamilton and applying the transfer matrix method, the solutions of state variables equation which are about free vibration of piezoelectric、piezomagnetic and elastic circular plate of single layer and multilayered are obtained. The calculation example indicates that from the varying law of the first natural frequency of the plate depending on the thickness-to-radius radio of the plate under varied conditions, the vibration properties of piezoelectric、piezomagnetic and laminated plate is related to the laminatation order of the material is gotten to know.

Abstract: In this paper, taking the underground cavities of Nuozadu Hydro-electrical Power Station located in Lancang River as an example, three-dimensional finite element numerical modeling technique is used to analyze systematically the distribution features secondary stress field, displacement field and failure zone in the surrounding rock mass of the underground cavities after the excavation when the surrounding rock mass quality rank change fromⅡ to IV. The influences of rock quality on excavation effects are discussed in detail.