Photogrammetry, as a tool for monitoring underground mine deformation, is an alternative to traditional point measurement devices, and may be capable of accurate measurements in situations where technolo- gies such as...Photogrammetry, as a tool for monitoring underground mine deformation, is an alternative to traditional point measurement devices, and may be capable of accurate measurements in situations where technolo- gies such as laser scanning are unsuited, undesired, or cost-prohibitive. An underground limestone mine in Ohio is used as a test case for monitoring of structurally unstable pillars. Seven pillars were pho- tographed over in a 63 day period, punctuated by four visits. Using photogrammetry, point clouds of the mine geometry were obtained and triangulation surfaces were generated to determine volumes of change over time. Pillar spaUing in the range of 0.29-4.03 m3 of rock on individual rib faces was detected. Isolated incidents of rock expansion prior to failure, and the isolated failure of a weak shale band were also observed. Much of the pillars remained unchanged during the monitoring period, which is indicative of proper alignment in the triangulated surfaces. The photographs of some ribs were of either too poor quality or had insufficient overlap, and were not included. However, photogrammetry was successfully aonlied to multiole ribs in auantifving the oillar geometrv change over time.展开更多
以前的地震预测物理基础的研究结果已“过期”了1973年美国肖尔兹(Scholz C H)等人在Science上发表了“地震预测的物理基础”一文,他们根据前人关于岩石膨胀的实验结果,提出了地震孕育的膨胀—扩散模式,由此预言地震前在地震的初始破裂...以前的地震预测物理基础的研究结果已“过期”了1973年美国肖尔兹(Scholz C H)等人在Science上发表了“地震预测的物理基础”一文,他们根据前人关于岩石膨胀的实验结果,提出了地震孕育的膨胀—扩散模式,由此预言地震前在地震的初始破裂区会出现P/S波速比、电阻率、水氡等多种前兆变化。但是,世界上多年来并未获得根据前兆变化成功预测强地震的实例,说明小岩样破裂实验的结果不能作为地震预测的物理基础。肖尔兹等人的论文所基于的实验是小尺度岩样发生静力学破裂的实验,当作用于岩样的差应力接近岩石的破裂强度时,应力-应变曲线会向下弯曲,这个破裂模型只能用来分析地震的初始破裂。由于每个地震不管大小,都有个初始破裂,按此破裂模型,似乎每个地震都可能出现“前兆”。实际并非如此。展开更多
文摘Photogrammetry, as a tool for monitoring underground mine deformation, is an alternative to traditional point measurement devices, and may be capable of accurate measurements in situations where technolo- gies such as laser scanning are unsuited, undesired, or cost-prohibitive. An underground limestone mine in Ohio is used as a test case for monitoring of structurally unstable pillars. Seven pillars were pho- tographed over in a 63 day period, punctuated by four visits. Using photogrammetry, point clouds of the mine geometry were obtained and triangulation surfaces were generated to determine volumes of change over time. Pillar spaUing in the range of 0.29-4.03 m3 of rock on individual rib faces was detected. Isolated incidents of rock expansion prior to failure, and the isolated failure of a weak shale band were also observed. Much of the pillars remained unchanged during the monitoring period, which is indicative of proper alignment in the triangulated surfaces. The photographs of some ribs were of either too poor quality or had insufficient overlap, and were not included. However, photogrammetry was successfully aonlied to multiole ribs in auantifving the oillar geometrv change over time.
文摘以前的地震预测物理基础的研究结果已“过期”了1973年美国肖尔兹(Scholz C H)等人在Science上发表了“地震预测的物理基础”一文,他们根据前人关于岩石膨胀的实验结果,提出了地震孕育的膨胀—扩散模式,由此预言地震前在地震的初始破裂区会出现P/S波速比、电阻率、水氡等多种前兆变化。但是,世界上多年来并未获得根据前兆变化成功预测强地震的实例,说明小岩样破裂实验的结果不能作为地震预测的物理基础。肖尔兹等人的论文所基于的实验是小尺度岩样发生静力学破裂的实验,当作用于岩样的差应力接近岩石的破裂强度时,应力-应变曲线会向下弯曲,这个破裂模型只能用来分析地震的初始破裂。由于每个地震不管大小,都有个初始破裂,按此破裂模型,似乎每个地震都可能出现“前兆”。实际并非如此。
