To extract the cable forces due to dead load in cable-stayed bridges from the monitoring data,the effects of various factors are eliminated step by step by different statistical methods.The information of cable tensio...To extract the cable forces due to dead load in cable-stayed bridges from the monitoring data,the effects of various factors are eliminated step by step by different statistical methods.The information of cable tension sensors recorded by the health monitoring system of Nanjing No.3 Yangtze River Bridge is taken as an example. Temperature effects are eliminated by linear fitting analysis;a 5-level wavelet de-noising method is applied to eliminate the noise signal by the wavelet basis function of DB8.The rest cable force data is tested by the method of extreme-value type-Ⅲ distribution, and the fitted location parameter is selected as the cable force due to dead load.The results show that the cable force has a linear relationship with temperature. Sometimes, the temperature effect is significant.Noise effect accounts for a small percentage,and the vehicle loads effect has twice the temperature effect on the traffic volume in 2007. The calculation results of other stay cables verify the reliability and validity of the proposed method.展开更多
By testing the temperature of the coal and the stress of the working surface, we got the variation law of coal temperature and coal stress during the excavation. The result shows that the activities of mining affect t...By testing the temperature of the coal and the stress of the working surface, we got the variation law of coal temperature and coal stress during the excavation. The result shows that the activities of mining affect the coal temperature, the fluctuation of coal temperature and the coal stress is synchronous. During the smooth change of crustal stress, the coal temperature basically keeps unchanged, when the dynamic phenomenon appears, the coal temperature changes, as well the coal stress. Therefore, we can use the online coal temperature monitoring system to test the coal temperature of the working surface continuously, and it can provide basic information for forecasting coal mine power disaster before it happens.展开更多
基金The National Natural Science Foundation of China(No.51208096)the Major Scientific and Technological Special Project of Jiangsu Provincial Communications Department(No.2014Y02)
文摘To extract the cable forces due to dead load in cable-stayed bridges from the monitoring data,the effects of various factors are eliminated step by step by different statistical methods.The information of cable tension sensors recorded by the health monitoring system of Nanjing No.3 Yangtze River Bridge is taken as an example. Temperature effects are eliminated by linear fitting analysis;a 5-level wavelet de-noising method is applied to eliminate the noise signal by the wavelet basis function of DB8.The rest cable force data is tested by the method of extreme-value type-Ⅲ distribution, and the fitted location parameter is selected as the cable force due to dead load.The results show that the cable force has a linear relationship with temperature. Sometimes, the temperature effect is significant.Noise effect accounts for a small percentage,and the vehicle loads effect has twice the temperature effect on the traffic volume in 2007. The calculation results of other stay cables verify the reliability and validity of the proposed method.
文摘By testing the temperature of the coal and the stress of the working surface, we got the variation law of coal temperature and coal stress during the excavation. The result shows that the activities of mining affect the coal temperature, the fluctuation of coal temperature and the coal stress is synchronous. During the smooth change of crustal stress, the coal temperature basically keeps unchanged, when the dynamic phenomenon appears, the coal temperature changes, as well the coal stress. Therefore, we can use the online coal temperature monitoring system to test the coal temperature of the working surface continuously, and it can provide basic information for forecasting coal mine power disaster before it happens.
