Advanced Materials Research Vols. 368-373

Abstract: Based on the geologic exploration materials and indoor test of Ji-He expressway,analysed the compaction characteristics of high liquid limit clay of the Yellow River alluvial plain,the relationship among compaction work and moisture content and dry unit weight,and the changing rules of the CBR value in different compaction works with the change of moisture content.Demonstrated that high liquid limit clay of the Yellow River alluvial plain can be used in expressway subgrades filling. Moreover, through the experimental sections of subgrades filling,the reasonable construction technology and quality controlling measures is put forward, and provides reference of subgrades filling with high liquid limit clay of the Yellow River alluvial plain.

Abstract: With the development of urban construction, urban transit network has been gradually improved, but subway tunnel under its normal operation is inevitably affected by underground engineering activities such as foundation pit engineering. Based on the deep excavation near the effects of tunnel, the research content of 3d finite element analysis, from the qualitative research based on different situations of foundation excavation, is near to optimize the design and construction to provide the beneficial reference.

Abstract: In order to analyze the mechanical properties parameters sensitivity of large section soil tunnel, this paper designs numerical test program of the degree of influence on mechanical properties by the change of physical and mechanical quantities based on the orthogonal experiment design. Depending on two-dimensional elastic-plastic finite element method, in this paper, multiple loading conditions numerical simulation has been carried out to level V wall rock large section tunnel in soil through double side drift construction method, and according to the numerical simulation results, the sensitivity extent wall rock parameters to the tunnel mechanical properties and stability, which may provide a basis for large section tunnel design calculation and construction.

Abstract: A group of model tests were designed to study the effect of horizontal load on the vertical bearing capacity of disk pile. Three double-disk piles were used in the test, and the distance of the two disks is 5 times as the disk diameter. Drew a horizontal load H=100N/200N/300N on the top of pile1/2/3 respectively, and put on the vertical load stage by stage, then studied the differences of three piles’ bearing properties such as changes of the pile bending moment, the horizontal and vertical deformation on the top, and soil pressure around the pile. Experiment showed that when the horizontal load is quite small, the existence of horizontal load has little to do with vertical bearing capacity. When the load reached a certain level, the p-∆ effect under the vertical load will significantly affect the vertical bearing capacity of the pile. Especially during the initial time while there is a large horizontal displacement or rotation generated by the horizontal load, the pile’s bearing capacity is controlled by the horizontal displacement.

Abstract: To investigate the dynamic transfer characteristics of low geosynthetic-reinforced embankments supported by CFG piles under high-speed train load, a numerical study has been conducted through dynamic finite element method on basis of the dynamic field test on a cross-section of Beijing-Shanghai high-speed railway. The comparative analysis on results of numerical study and field test indicated the distribution characteristics of vertical dynamic stress induced by high-speed train load in subgrade soil under railway line. The numerical results also suggested a high stress area in subgrade where vertical dynamic stress is over 1kPa. Conclusions of this work can provide reference for both design and estimation of long-term settlement of low geosynthetic-reinforced embankments supported by CFG piles for high-speed railway.

Abstract: The paper derives the similarity criterion aiming at the characteristics of repairing the drainage pipe with the method of the liquid nitrogen freezing in the connecting passage of metro tunnel, and establishes the simulated test system of the liquid nitrogen freezing based on the similarity theory. Through the simulated testing on repairing the drainage pipe with the method of liquid nitrogen freezing in the connecting passage of metro tunnel, we get the regulation of the temperature distribution of the freezing pipe wall, the regulation of the development of the freezing temperature field and the the frost heave displacement.The study instructs the repairing drainage pipe with the method of liquid nitrogen freezing in the connecting passage of metro tunnel, and promotes the development of the thoery of the liquid nitrogen freezing, also provides the reference and improvement for the engineering and study in the future.

Abstract: According to measured shear wave velocity of Xi’an Bell Tower area (Loess Area), the dynamic parameters of site soil are determined by using the relationship between shear wave velocity and compression wave velocity. Using Matlab program, the finite element size for low frequency subway vibration is obtained by analyzing soil dispersion phenomenon. On this basis, two-dimensional model with viscous - elastic boundaries is established by using the ANSYS program. The load-time history of the train is applied to the right tunnel, and the effects of the depth and breadth of the different models on the ground vibration velocity are discussed. Finally, the dimensions and element sizes of finite element model are obtained for the Xi'an No. 2 Metro Line with 15m depth in the loess regions.

Abstract: This paper focuses on the power gaining in Nantong planning (1895-1926), and the role that an individual could play in local city planning issues. This study analyzes the evolution of Zhang’s power gaining in four periods through reviewing literatures, investigating historical remains, and interviewing the scholars studying on Zhang. The conclusions are as follows: Firstly, Zhang inherited the power in deal local issues as local elite. Secondly, he tried for new powers by borrowing the concept of Local Self-governance from the west. Thirdly, he also could make new powers through business approaches.

Abstract: Through a comparison on the community support for the elderly at home(SSEH) carried out in three communities in Beijing in recent years this paper aims to analyze the conditions both of hardware and software in communities, then summarize the features of supporting system for the elderly at home. The research approaches consist of case study and Comparative method. The conclusions are as follows: 1) According to traditional and practical situation of each community the SSEH appears diversification in form and leading subjects, which could be divided into three main types: government-lead community-lead and market-lead; 2) Three type SSEHs develop different multi-actor and multi-level network regarding integration of various elderly-related resources within community respectively.

Abstract: Using the ordinary digital camera to obtain the single image of the ancient building there are three sets of parallel lines perpendicular to each other, the model has been established to solver 3D relative coordinates of the ancient building according to the pixel coordinates of the ancient building. As long as a basic length of ancient building is measured, using the calculated 3D relative coordinates, the real structure size of the ancient building will be fully restored, and so the elevation drawing of the ancient building will be also drawn. The method has an important practical significance for the protection of ancient building.