Applied Mechanics and Materials Vols. 90-93

Abstract: Housing performance is an important and widely studied topic since it has significant impact on architecture design and programming. In terms of problems existing in the field, a new support vector machine technology, potential support vector machine, is introduced and then combined with decision tree to address issues on supplier selection including feature selection, multi-class classification and so on. And the methodology proposed in the paper, which is proved to the strengthens of integrating knowledge and experiences from experts in the paper, can be applied in housing performance evaluation which is one of complex issues combined with processes including not only quantitative, but also qualitative analysis.

Abstract: As the joint connecting urban and rural areas, the special ways are needed in the spatial urban planning & design of the urban marginal areas. Based on the cases of environmental planning in Harbin’s marginal area under urban expansion background, the paper discusses the interdependent and symbiotic relationship between city and natural environment, and explores the effective modes finding, changing and utilizing the value elements of suburban environment. Finally the paper puts forwards spatial planning & design strategies oriented in the discovery and utilization of environmental value for urban marginal area according to the location characteristics of the urban marginal areas and value embodiment of natural environmental conditions, such as ecological priority, advantages intensification and images construction.

Abstract: Based on summarizing the purpose and main working conditions of horizontal analysis of the box beam in bridges, combined with the force status of the chambers under the radial force of the bottom slab in Zhaohua Beijiang Bridge, the stress distribution in the cross-section under the pre-stressed radial force of the bottom slab at the center of a span of 210m and 85m respectively is analyzed with finite element method. The horizontal and vertical stress distribution and chambers displacement under the radial force are respectively researched. The results show that appropriate size should be used in the angle between both sides and the end of a box beam with a large span; the box beam lower, the girder webs bending stress generated by the radial force greater; the bending stress of the webs weakens their own principal stress state. These conclusions have certain significances for the study of the box girder stress, deformation and crack control.

Abstract: This paper presents simulation analysis of load effects of bridges under random fleet. Based on actual data of vehicle loads on Guangzhou-Shenzhen Expressway and relevant statistical results, mid-span bending moments of long-span virtual simple-supported beams are calculated. Then probability distribution of the bending moments and extreme value distribution of the load effects within design reference period are obtained. Finally, characteristic values of mid-span bending moments and recommended values of design lane load are calculated, sequentially. The results studied in this paper can be as a reference for long-span bridge design, and also can be a reference for overloading control or weight charge policy.

Abstract: This paper presents statistical analysis of vehicle loads, which were measured by Weighing in Motion (WIM). The vehicle composition, distribution of gross vehicle weight (GVW) and load distribution of classified vehicles are obtained; Axle load proportions and wheelbases of different type of vehicles are also statistically analyzed. Based on statistic theory of extreme value distribution, characteristic values of different type of vehicle loads within design reference period are deduced. The analysis results can be used for safety evaluation of road pavements, bridges and culverts in the expressway, and can be as a reference for both design load formulation and overloading control of bridges.

Abstract: The dynamic characteristics of cable-stayed bridge will be affected greatly by soil action. In the paper, a spatial dynamic analysis model of a cable-stayed bridge was built by using the general finite element software ANSYS. The dynamic characteristics of the frequencies and modal shapes are investigated and compared with considering the pile-soil-structure interaction or not. From the analysis, the results indicate that if the pile-soil-structure interaction is taken into account, there will have a significant effect on the dynamic behaviors of bridge.

Abstract: With both the high efficiency and economic advantages, the incremental launching has been widely used in bridge construction. As the steel U girder of the composite bridge has not formed the designed section during the launching construction, it has small stiffness relatively and poor torsion resistance ability. The structure mechanical behaviors are complex. Bridge structure collapsed during the incremental launching construction had been reported. Real-time strain monitoring of the adverse sections of the structure during the launching has important significance. By taking the Hangzhou Jiubao Bridge as background, this article introduced the real-time strain monitoring of the steel U girder and analyzed the monitoring results. Effective mastery of the safe state of the structure during launching construction was achieved. It had ensured the launching construction finished successfully. The research results can provide a reference for the design and construction of other similar engineering.

Abstract: Several equations for punching shear strength of the reinforced concrete slab have been proposed in the world. These equations have their own factors affecting the strength. There are numerous test data for punching shear strength of RC slabs, which have been obtained by numerous researchers. A database with approximately 300 specimens has been structured through the present study. In the present study seven equations for punching shear strength are evaluated based on the database. CCES equation is also evaluated from the present database.

Abstract: A typical reinforced concrete rib arch bridge was chosen to investigate its nonlinear response to near-fault ground motions recorded in 2008 Wenchuan earthquake. Results showed that significant seismic damage may occur, maximum demands were higher for near-fault records having forward directive than far-fault motions, and the rotational capacity of rib plastic hinge is not enough for the large compression force of arch rib. While backward-directivity motions, typically do not exhibit pulse-type motions, only have medium seismic damage to the arch bridge.

Abstract: According to the behavior of seismically isolated continuous bridges, the bidirectional nonlinear characteristics of lead rubber bearing are taken into account by using two orthogonal nonlinear level spring elements. Based on the FEA software, the analysis models of seismically isolated and non-isolated continuous bridges are established. And the nonlinear seismic response for these analysis models is carried out under the function of the reasonably chosen seismic motion. The analytic results indicate that the natual period of seismically isolated bridge can be prolonged to avoid the principal period of ground and the seismic energy of structure can be efficiently consumed by the hysteretic energy dissipation of lead rubber bearing. So the response of bridge structure can be reduced to make sure most of the component work in the elastic phase and the structure can be well protected.