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Xia C.,Tongji University | Chen X.,Tongji University | Chen X.,Fujian Electric Power Survey and Design Institute | Xu C.,Tongji University | Zhao X.,Tongji University
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2010

Jinjishan tunnel in project of Fuzhou airport expressway construction is multi-arch tunnel with eight lanes in China. In surrounding rock of the tunnel, joints were developed which cut the original rock blocks into even smaller blocks. The blocks can be easily disturbed and become unstable during tunnel excavation. To keep the blocks stable is one of the most important problems in construction of the highway tunnel. Data of joints unveiled during excavation in several cross-sections of mid-drift of the tunnel and other areas are collected in detail and described meticulously. Based on statistical analysis of the data, distribution of joints in whole face tunnel relative to the same cross-section is forecasted. The block theory is adopted to study the location, volume, sliding force, safety factor and other parameters of key blocks in the cross-sections of whole face tunnel. Mechanical calculations of stability are performed to analyze the key blocks in different situations which are the none of reinforced situation, reinforced by anchors situation, and reinforced by anchors and shotcrete situation. The situations are evaluated and advices are made for the engineering application of the tunnel. Source

Fang Y.-L.,Fujian Electric Power Survey and Design Institute | Lu Z.,Fujian Province Power Dispatch and Communication Center | Song F.-H.,Fujian Province Power Dispatch and Communication Center | Xia K.-Q.,NARI Group | Qi Z.,NARI Group
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2013

In order to meet the construction of regulation integration system and improve intelligent fault information analysis system of relay protection in power grid, this paper designs a practical implementation scheme for relay protection and intelligent fault analysis system. In the proposed scheme, models of primary device and secondary device are unified based on integrative information platform and hierarchical distributed structure. Fault recorder data is uploaded by different channels, in main substation side, fault diagnosis and analysis is made based on multi-source information in EMS, fault information system and fault recording system. Furthermore, a compatible solution is also put forward for the transitional stage of intelligent fault information analysis system. The system has been run in Fujian Power Grid, and the operation status show that the intelligent analysis of relay protection fault information system can be achieved well, providing reference for construction of power system fault information intelligent assistant-decision-making system. Source

Huang X.-F.,Fujian Electric Power Survey and Design Institute
Gaodianya Jishu/High Voltage Engineering | Year: 2010

OPGW which is grounded at every tower causes more energy losses. Energy losses can be reduced largely by the improved grounding methods of OPGW which is grounded at one single point in one line section or insulated entirely in whole line. Taking a 500 kV double circuit transmission line on the same tower as an example, we used the improved grounding method of OPGW to analyze and calculate the related induced voltage and circuit parameters in normal, fault and maintenance conditions, and presented the type selection and assembly method for these special components. Analysis of each component in OPGW line system indicates that the OPGW line system adopting the improved grounding method can be achieved approximate safety and reliability level of the OPGW line system which is grounded at every tower. Therefore, the improved grounding method of OPGW is technically feasible and is of a positive significance to construction of "energy-saving, environmental protection" transmission line. Source

Deng H.,Tongji University | Zhang J.,Tongji University | Shuai Q.,Tongji University | Chen Q.,Fujian Electric Power Survey and Design Institute
Dianwang Jishu/Power System Technology | Year: 2010

The high frequency force balance (HFFB) test in wind-tunnel for both models of steel tubular transmission tower, whose type is SZT2, and its cross arms adopted in 1000 kV power transmission project from Huainan to Shanghai, and the mean wind load acting on the models and corresponding pressure coefficients are obtained. Test results show that the least favorable wind direction angles for steel tubular transmission tower are 15° and 75°; the pressure coefficient of 0.80 for steel tubular tower body and that of 0.85 for steel tubular cross arms can meet design requirements. Source

Wang S.,Nanjing University | Wang S.,Southwest Branch of China Airport Construction Group Corporation of CAAC | Chen Z.-Z.,Nanjing University | Wu Q.,Fujian Electric Power Survey and Design Institute | And 2 more authors.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2013

The orientations of joints which obey the Fisher distribution are simulated according to the Monte Carlo method. The safety factor of each simulated orientation is calculated and the distribution rules of safety factor and the reliability of slopes are obtained by statistical fitting. In order to consider the sensitivity of safety factor to dip direction and dip of joints simultaneously, an idea that the sensitivity of safety factor to the orientation is represented by that to spherical distance of normal vector is proposed. It is also suggested to characterize the sensitivity to arbitrary orientation by means of the sensitivity of average and the maximum value. Drawing safety factor and sensitivity contour map on stereonet makes it possible to visualize the analysis results. The analysis of a specific problem shows that the recommended analytical methods are helpful to gain a complete and intuitive view of the effect of joint uncertainty on safety factor. The potential safety concerns due to the discrete measured data of orientations may be eliminated and the deficiency that the sensitivity analysis is formerly processed by dealing with dip and dip direction respectively can be solved. Source

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