Study on Concrete Dam Temperature Evaluation Based on Distributed Optical Fiber Temperature

2012 ◽  
Vol 204-208 ◽  
pp. 457-462
Author(s):  
Yao Ying Huang ◽  
Dan Dan Liu ◽  
Li Xin Qu ◽  
Yi Hong Zhou
Keyword(s):  
Optical Fiber ◽  
Temperature Control ◽  
Evaluation System ◽  
Weak Link ◽  
Arch Dam ◽  
Control Measures ◽  
Entropy Weight ◽  
Weighting Method ◽  
Technical Requirements ◽  
Distributed Optical Fiber

The dam concrete material properties wre influenced by the implementation of temperature control measures on site. The weekly temperature evaluation system has been set up in order to evaluate current temperature control measures, combining with the distributed optical fiber temperature control techniques and construction technical requirements. The system has been applied to a concrete arch dam under construction in southwest China which established multi-objective fuzzy mathematical model by synthetic weighting method that was a combination of experts scoring method and entropy weight method. Practice shows that the system can estimate weak link of this week and give guidance to the temperature control’s adjustment of the following week.

scholarly journals Research on concrete temperature control measures in deep hole area of super high arch dam

2021 ◽  
Vol 826 (1) ◽  
pp. 012035
Author(s):  
Yuchen Fu ◽  
Yaosheng Tan ◽  
Chunfeng Liu ◽  
Lei Pei ◽  
Yajun Wang ◽  
...  
Keyword(s):  
Temperature Control ◽  
Arch Dam ◽  
Control Measures ◽  
Deep Hole ◽  
High Arch Dam ◽  
Hole Area ◽  
Concrete Temperature

Distributed Optical Fiber in High RCC Arch Dam Project

2013 ◽  
Vol 312 ◽  
pp. 639-643
Author(s):  
De Suo Cai ◽  
Hao Tang ◽  
Ye Shui Guo
Keyword(s):  
Optical Fiber ◽  
Temperature Measurement ◽  
Measurement System ◽  
Cooling Water ◽  
Heat Of Hydration ◽  
Arch Dam ◽  
Technical Requirements ◽  
Rcc Arch Dam ◽  
Under Construction ◽  
Temperature Measurement System

As the highest RCC(Roller Compacted Concrete) arch dam under construction around the world, Wanjiakouzi adopted advanced distributed temperature system (DTS). This paper summarizes the network design, technical requirements as well as the protection precautions of fiber connector and monitoring port of temperature measurement system of optical fiber in high RCC arch dam in Wanjiakouzi. It can be indicated that the accuracy and reliability of DTS by comparing fiber optic temperature values with the conventional thermometer measured values. The analysis and monitoring results show that the temperature measurement system of optical fiber can truly monitor and reflect the change process of heat of hydration of RCC, gradation and the cooling water pipe to temperature.

scholarly journals Study on Optimization of Temperature Control Measures for Structure Concrete of Arc Dam

2021 ◽  
Author(s):  
Lei Zhang ◽  
Xiaofang Ma ◽  
Heng Zhao ◽  
Lei Zheng ◽  
Shouxun Ma
Keyword(s):  
Phase I ◽  
Temperature Stress ◽  
Temperature Control ◽  
Simulation Analysis ◽  
Complex Structure ◽  
Arch Dam ◽  
Control Measures ◽  
3D Fem ◽  
Water Pipes ◽  
Cooling Temperature

As the gate pier bracket of an arch dam are of complex structure which is characterized by use of high-grade concrete and more cement, higher adiabatic temperature rise, it is rather difficult to control temperature and vulnerable for cracking, and the cracks would absolutely affect the integrity, endurance and safety of pier gate bracket. It is necessary to take reasonable temperature control measures to reduce temperature stress during the construction and prevent cracking. This paper takes the gate pier bracket at the middle-hole dam section to perform simulation analysis of temperature field and stress field under different temperature control measures by 3D FEM. It proves that such measures as densifying water pipes, improving Phase I target cooling temperature appropriately, reducing Phase I cooling temperature falling variation and keeping insulation in low-temperature season can help reduce temperature stress and prevent cracking with good results.

scholarly journals Intelligent Evaluation System of Water Inrush in Roadway (Tunnel) and Its Application

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 997 ◽  
Author(s):  
Shaoshuai Shi ◽  
Xiaokun Xie ◽  
Zhijie Wen ◽  
Zongqing Zhou ◽  
Liping Li ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Mine Water ◽  
Evaluation System ◽  
Water Inrush ◽  
Technical Problem ◽  
Control Measures ◽  
Mine Safety ◽  
Water Control ◽  
Entropy Weight ◽  
Entropy Weight Method

The risk assessment of mine water inrush is a complicated theoretical and technical problem that concerns hydrogeology conditions, engineering geology, mining conditions, rock mechanics, etc. To address this problem, a software system for the risk assessment of mine water inrush was established. From the matter-element extension theory, combined with the entropy-weight method, a matter-element extension entropy-weight model was constructed to evaluate mine safety. Eleven indices were determined based on the principles of science, rationality, operability, and representation, and each index was quantitatively graded. This system had built-in abundant cases of typical mine water inrush so users could determine the value of the parameter according to the analogy of water inrush cases with similar conditions. Combined with the analysis of typical water inrush cases, a database of water control measures with a strong advisory function was established. Finally, through the case study of a typical mine, it was found that the results of this study agreed with the practical ones, indicating that this system could improve the accuracy and availability of the risk assessment of mine water inrush.

scholarly journals Rational Supplier Selection Based on Two-Phase Deep Analysis considering Fuzzy QFD and Game Theory

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Feng Li ◽  
Senhao Luo ◽  
Yi Wang ◽  
Chia-Huei Wu
Keyword(s):  
Game Theory ◽  
Evaluation System ◽  
Supplier Selection ◽  
Quality Function Deployment ◽  
Comprehensive Evaluation ◽  
Fuzzy Comprehensive Evaluation ◽  
Entropy Weight ◽  
Two Phase ◽  
Weighting Method ◽  
Fuzzy Qfd

Viewing from the perspective of a traditional manufacturing enterprise, the paper proposes a fuzzy comprehensive evaluation system model, which selects the most suitable supplier or suppliers to undertake the supply tasks and to achieve the purposes of reducing procurement costs and improving the supply quality and reliability, so as to fully meet customer demands. Based on decision-makers’ preferences and suppliers’ supply capabilities, subjective and objective weight of criteria are both developed for supplier selection with the corresponding weighting method, namely, quality function deployment (QFD) and entropy weight. Specially, the two-phase fuzzy QFD method combined with the trapezoidal fuzzy number (TFN) is creatively applied to realize the complicated conversion process. Furthermore, the game theory is employed to combine the advantages of the subjective and objective weighting method, by which the comprehensive weight can be determined. A numerical example is given to demonstrate the proposed modeling process. Through programming drawing images for comparative analysis and sensitivity analysis, study image trends, and draw conclusions, the proposed model effectively alleviates the weight deviation and has higher rationality and extensibility in supplier selection.

scholarly journals Arch dam temperature control curve adjustment and its impact

2021 ◽  
Vol 826 (1) ◽  
pp. 012055
Author(s):  
Janming Wu ◽  
Yaosheng Tan ◽  
Chunfeng Liu ◽  
Lei Pei ◽  
Yajun Wang ◽  
...  
Keyword(s):  
Temperature Control ◽  
Arch Dam ◽  
Control Curve

scholarly journals Measurement Improvement of Distributed Optical Fiber Sensor via Lorenz Local Single Peak Fitting Algorithm

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1166
Author(s):  
Bin Liu ◽  
Jianping He ◽  
Shihai Zhang ◽  
Yinping Zhang ◽  
Jianan Yu ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Frequency Shift ◽  
Optical Fiber Sensor ◽  
Gain Spectrum ◽  
Fiber Sensor ◽  
Peak Fitting ◽  
Fitting Algorithm ◽  
Distributed Optical Fiber Sensor ◽  
Brillouin Gain ◽  
Distributed Optical Fiber

Brillouin frequency shift (BFS) of distributed optical fiber sensor is extracted from the Brillouin gain spectrum (BGS), which is often characterized by Lorenz type. However, in the case of complex stress and optical fiber self damage, the BGS will deviate from Lorenz type and be asymmetric, which leads to the extraction error of BFS. In order to enhance the extraction accuracy of BFS, the Lorenz local single peak fitting algorithm was developed to fit the Brillouin gain spectrum curve, which can make the BSG symmetrical with respect to the Brillouin center frequency shift. One temperature test of a fiber-reinforced polymer (FRP) packaged sensor whose BSG curve is asymmetric was conducted to verify the idea. The results show that the local region curve of BSG processed by the developed algorithm has good symmetry, and the temperature measurement accuracy obtained by the developed algorithm is higher than that directly measured by demodulation equipment. Comparison with the reference temperature, the relative measurement error measured by the developed algorithm and BOTDA are within 4% and 8%, respectively.

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