Manufacturing Science and Technology, ICMST2011

Volumes 383-390

doi: 10.4028/www.scientific.net/AMR.383-390

Paper Title Page

Authors: Guo Zhong Huang, Zhong Guang Wu, Can Sheng Yang, Hui Liu
Abstract: Given factors influencing construction safety has characteristics of fuzziness and uncertainty, an evaluation model based on Fuzzy-Set Pair Analysis is put forward, which combines advantages of fuzzy comprehensive analysis method and set pair analysis method. According to characteristics of construction, the construction safety evaluation index system is constructed, the weight of each index is determined by Interval Analytic Hierarchy Process (IAHP) and connection degree is calculated, so the safety condition development and uncertainty rank of evaluated construction sites are calculated. It is shown that the model can deal with certainty and uncertainty of information in safety evaluation at the same time, thus good results can be obtained through application of the model.
6587
Authors: Jian Guo, Qi Cai Wang
Abstract: The bench method dynamic construction process of Xin Baotashan tunnel which located in the grade IV surrounding rock is simulated by using the finite element method. The variation of displacement and stress field of the surrounding rocks and the internal force of the lining structures during every excavation step is calculated. The state of the surrounding rocks can be predicted by the numerical simulation results, and the construction plan and construction sequences can be guided by the analysis results. At the same time the reasonability and feasibility of the design parameters can be judged by analyzing the internal forces of the lining structures. Analysis and experimental results showed that the stability of the surrounding rocks is good by using the bench method construction to the IV grade surrounding rocks and the design parameters of the lining structures are feasible.
6594
Authors: Xing Chong Chen, Xiu Shen Xia, Li Li Xing
Abstract: Performance objectives and contents of resistance verification for high speed railway bridge are embodied and quantified based on the theory of performance-based seismic design. The resistance verification is proposed, which can control the damage under design earthquake and ensure safety of the pier under low-level earthquake. The simplified capacity spectra method for calculating displacement ductility factor is proposed by using strength reduction factor. The method for evaluating damage of RC bridge pier in high-level earthquake is presented by using maximum displacement and hysteretic energy. The proposed approach and procedures for performance-based seismic design are easily to implement. The performance-based seismic design procedure is demonstrated by using an example.
6601
Authors: Ya Xin Su, Xin Wan
Abstract: Natural ventilation in an workshop of iron and steel company has been numerically simulated by computational fluid dynamics (CFD) method. Realizable k −ε turbulent model combined with a DO radiation model which took into account the radiation between the heat source and the wall was applied to carry out the simulation for a typical industrial workshop. Numerical results were verified by published experimental data of local temperature and further modification of the workshop structure was made based on numerical calculation to improve the natural ventilation effect further.
6608
Authors: Xin Ling Ma, Xiang Rui Meng, Xin Li Wei, Jia Chang, Hui Li
Abstract: This paper presents energy analysis, thermodynamic calculation and exergy analysis for waste heat power generation system of Organic Rankine Cycle based on the first and second laws of thermodynamics. In order to improve system performance, for low-temperature waste heat of 120°C and R245fa organic working fluid, using Aspen Plus software conducted simulation, optimization and improvement. Results from these analyses show that decreasing the expander inlet temperature, increasing inlet pressure of the expander, and adding regenerative heater can increase thermal and exergy efficiencies, at the same time reduce system irreversibility.
6614
Authors: Chang Sheng Guan, Zhao Wan
Abstract: In order to provides the theory basis for the optimization design of ground source heat pump underground U-shaped buried tube, ANSYS software was used to simulate the temperature field distribution of GSHP buried tube summer cooling process. The dynamic simulation was base on analyzing the GSHP heat exchanger unsteady heat transfer model. Comparing the temperature field distribution radius in different soil heat transfer rate, the simulation results show that the buried tube heat transfer efficiency increases with soil coefficient of thermal conductivity, soil hot effect radius increased over time and tend to be gentle.
6621
Authors: Cheng Ju Huang, Chang Sheng Guan, Kai Xia
Abstract: The random properties on buried pipe of ground-source heat pump (GSHP) is analyzed, the equation of Kelvin one-dimensional line source of heat transfer model is discussed. The model randomness is analyzed also, and the GSHP buried pipe to random excess temperature field, space-time statistics and the correlation of features are studied. The engineering example shows that heat transfer in buried pipe has relationship with the distance from the pipe center and run time of the system, and also the heat transfer between buried pipes can not be ignored. The method in this paper has great significance for improving the reliability design theory and reducing the construction cost of GSHP buried pipe in this paper.
6626
Authors: Yao Dong Zhou, Zhong Xue Li, Cui Ping Li, Zhi Guo Cao
Abstract: There exists a high risk of water-inrush in mining activities. Therefore, it is critical to develop a conceptual model of Mine Water-inrush, especially for the underground environment. The general structure of Mine Water-inrush Simulation System consists of core network, the underground monitoring network, and the operational system. Through the application of data processing system, simulation system and the application system, the original data can be processed. The results is then passed to the operators and managers, which require them increase the understanding of factors leading to accidents and consequently take action to improve mining safety. This new water-inrush model captures three characteristics to regard the mine water-inrush: the inrush sources, inrush process, and submerging process. Virtual length has been applied to the model, which is combined with a Traversal Algorithm, can be used to calculate the area of increased influence over time for each process. Based on the collected data from a real mine, the underground excavations and a virtual water-inrush disaster process were simulated, which shows that the system operates reliably.
6632
Authors: Ming Bo Ding, Xing Chong Chen
Abstract: This paper mostly studied on the pile stress in the loess foundation when the pile and the soil are interacting by pseudo-static test of piers and piles in the remolded loess foundation indoor. We get the stress-depth curve of pile body. We get its finite element model by ANASYS and analyze the change of pile body stress.
6641
Authors: Li Xin Yan, Ai Bing Jin
Abstract: By analyzing the stability factors and deformation characteristics of wall rock of dynamical pressure roadway in coal mine, the basic support form of dynamical pressure roadway was summarized. Combined with the geological conditions and the roadway damaged condition of two tape head chamber in ChengZhuang colliery No.2 area, the reinforcement approach was put forward, which adopting the composite grouting of cement and unsaturated polyester chemical pulp, then strengthened by prestressed grouting anchor. Comparing the supporting effect of prestressed grouted anchor with not grouted, it was obviously found that the effect is great improved. The strong deformation of dynamic pressure roadway can be solved effectively in this way.In recent years, with the development of mining technology and high-gas coal mining, the roadway layout that can meet the requirements of production and ventilation is increasingly complicated. The area of roadway increases as equipment have been expanding. The pressure has been apparently increasing because the thickness of mining and the height of caving face increase. The difficulty level of roadway support is also added since the surrounding rock condition become more and more complex [1-3].
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