This paper reviews the recent achievements made by our team in the mitigation of rockburst risk. It includes the development of neural network modeling on rockburst risk assessment for deep gold mines in South Af- ric...This paper reviews the recent achievements made by our team in the mitigation of rockburst risk. It includes the development of neural network modeling on rockburst risk assessment for deep gold mines in South Af- rica, an intelligent microseismicity monitoring system and sensors, an understanding of the rockburst evolution process using laboratory and in situ tests and monitoring, the establishment of a quantitative warning method for the location and intensities of different types of rockburst, and the development of measures for the dynamic control of rockburst. The mitigation of rockburst at the Hongtoushan copper mine is presented as an illustrative example.展开更多
Through analyzing the failure mechanics of rock under blasting effect, the optical fiber sensing system was used to monitor the strain of surrounding rock under blasting effect. Combined with practical exploration, th...Through analyzing the failure mechanics of rock under blasting effect, the optical fiber sensing system was used to monitor the strain of surrounding rock under blasting effect. Combined with practical exploration, the stability of surrounding rock was computed by numerical simulation using the blasting wave obtained from the site. According to the change regularities of displacement, stress, acceleration, and velocity of tunnels before and after explosion, the layout of key monitoring points was optimized. When disposed the monitoring position of sensors, the regular points should be considered to use as key points and the periodical monitor should be a part of the long-term monitor. In practical application, considering the geology condition in site, monitor points should be added on the area with joints and faults to assure the integrity of monitor data and the preciseness of decision.展开更多
NOAA National Status and Trends Mussel Watch Report indicate the Delaware Bay has regionally medium levels of Cd and high levels of Pb. Environment New Jersey, a non-profit environmental group, reported the Delaware R...NOAA National Status and Trends Mussel Watch Report indicate the Delaware Bay has regionally medium levels of Cd and high levels of Pb. Environment New Jersey, a non-profit environmental group, reported the Delaware River, providing drinking water to millions, as the fifth most-polluted river in the country. These concerns resulted in this study monitoring water quality conditions near a wastewater facility in Delaware. Physical water quality parameters were measured, along with heavy metals Cd and Pb. Mean metal levels were consistently low at the wastewater discharge (1.3 μg/L Cd, 5.1 μg/L Pb), and high at the control location (9.2 μg/L Cd and 11.5 μg/L of Pb). Relationships were observed between heavy metals, salinity and pH levels. Results suggest water treated by the facility does not pose heavy metal contamination risks to the Lewes Rehoboth Canal. Further studies are warranted to seek heavy metal sources at the control point, farthest from the waste water treatment facility.展开更多
飞机结构损伤导波在线监测技术作为一种新颖的无损检测手段,为了真正实现该技术在结构运营维护过程中的视情维护,必须明确其结构损伤检出概率(probability of detection,POD),以指导结构检查维修方案的制定。提出了一种基于信号响应分...飞机结构损伤导波在线监测技术作为一种新颖的无损检测手段,为了真正实现该技术在结构运营维护过程中的视情维护,必须明确其结构损伤检出概率(probability of detection,POD),以指导结构检查维修方案的制定。提出了一种基于信号响应分析模型的结构损伤导波POD计算方法,该方法通过构建在线导波监测信号的损伤指数与裂纹长度间的对应关系,得到结构损伤POD的统计计算模型,并分析了拟合参数的不确定性对计算模型的影响,构建了不同置信度下的导波POD计算模型。通过开展金属开孔和搭接结构疲劳裂纹导波监测试验,验证了该方法的有效性。试验结果表明,损伤指数类型、对应关系拟合函数和传感器监测方案均对结构损伤导波POD具有影响,且在95%置信度90%POD下金属开孔和搭接结构的可检裂纹长度分别约为2.6 mm和9.5 mm。展开更多
针对金属表面裂纹的多特征监测问题,提出了一种基于射频识别(Radio Frequency Identification, RFID)技术的裂纹多特征监测方法。首先,设计了一种RFID标签阵列,通过裂纹影响标签反射信号的相位特征来感知裂纹特征。然后,设计了一种基于...针对金属表面裂纹的多特征监测问题,提出了一种基于射频识别(Radio Frequency Identification, RFID)技术的裂纹多特征监测方法。首先,设计了一种RFID标签阵列,通过裂纹影响标签反射信号的相位特征来感知裂纹特征。然后,设计了一种基于几何法的裂纹粗定位算法,利用粗定位结果结合指纹法进行细粒度定位,计算得到裂纹的方向、位置和宽度。最后,通过在不同标签阵列密度以及指纹密度的情况下进行仿真,并进行真实实验来验证该算法的有效性和准确性。仿真及实验结果表明,与传统RFID指纹法相比,所提方法能有效降低裂纹多特征监测误差。展开更多
基金The authors gratefully acknowledge financial support from the National Natural Science Foundation of China （51621006, 413200104005, and 11232014）.
文摘This paper reviews the recent achievements made by our team in the mitigation of rockburst risk. It includes the development of neural network modeling on rockburst risk assessment for deep gold mines in South Af- rica, an intelligent microseismicity monitoring system and sensors, an understanding of the rockburst evolution process using laboratory and in situ tests and monitoring, the establishment of a quantitative warning method for the location and intensities of different types of rockburst, and the development of measures for the dynamic control of rockburst. The mitigation of rockburst at the Hongtoushan copper mine is presented as an illustrative example.
文摘Through analyzing the failure mechanics of rock under blasting effect, the optical fiber sensing system was used to monitor the strain of surrounding rock under blasting effect. Combined with practical exploration, the stability of surrounding rock was computed by numerical simulation using the blasting wave obtained from the site. According to the change regularities of displacement, stress, acceleration, and velocity of tunnels before and after explosion, the layout of key monitoring points was optimized. When disposed the monitoring position of sensors, the regular points should be considered to use as key points and the periodical monitor should be a part of the long-term monitor. In practical application, considering the geology condition in site, monitor points should be added on the area with joints and faults to assure the integrity of monitor data and the preciseness of decision.
文摘NOAA National Status and Trends Mussel Watch Report indicate the Delaware Bay has regionally medium levels of Cd and high levels of Pb. Environment New Jersey, a non-profit environmental group, reported the Delaware River, providing drinking water to millions, as the fifth most-polluted river in the country. These concerns resulted in this study monitoring water quality conditions near a wastewater facility in Delaware. Physical water quality parameters were measured, along with heavy metals Cd and Pb. Mean metal levels were consistently low at the wastewater discharge (1.3 μg/L Cd, 5.1 μg/L Pb), and high at the control location (9.2 μg/L Cd and 11.5 μg/L of Pb). Relationships were observed between heavy metals, salinity and pH levels. Results suggest water treated by the facility does not pose heavy metal contamination risks to the Lewes Rehoboth Canal. Further studies are warranted to seek heavy metal sources at the control point, farthest from the waste water treatment facility.
文摘飞机结构损伤导波在线监测技术作为一种新颖的无损检测手段,为了真正实现该技术在结构运营维护过程中的视情维护,必须明确其结构损伤检出概率(probability of detection,POD),以指导结构检查维修方案的制定。提出了一种基于信号响应分析模型的结构损伤导波POD计算方法,该方法通过构建在线导波监测信号的损伤指数与裂纹长度间的对应关系,得到结构损伤POD的统计计算模型,并分析了拟合参数的不确定性对计算模型的影响,构建了不同置信度下的导波POD计算模型。通过开展金属开孔和搭接结构疲劳裂纹导波监测试验,验证了该方法的有效性。试验结果表明,损伤指数类型、对应关系拟合函数和传感器监测方案均对结构损伤导波POD具有影响,且在95%置信度90%POD下金属开孔和搭接结构的可检裂纹长度分别约为2.6 mm和9.5 mm。
文摘针对金属表面裂纹的多特征监测问题,提出了一种基于射频识别(Radio Frequency Identification, RFID)技术的裂纹多特征监测方法。首先,设计了一种RFID标签阵列,通过裂纹影响标签反射信号的相位特征来感知裂纹特征。然后,设计了一种基于几何法的裂纹粗定位算法,利用粗定位结果结合指纹法进行细粒度定位,计算得到裂纹的方向、位置和宽度。最后,通过在不同标签阵列密度以及指纹密度的情况下进行仿真,并进行真实实验来验证该算法的有效性和准确性。仿真及实验结果表明,与传统RFID指纹法相比,所提方法能有效降低裂纹多特征监测误差。
