Estimation of large landslide around the Yangtze River with the measurement of electromagnetic radiation

本文对长江流域大型滑坡进行了估算。为了研究三峡库区滑坡区的地质背景和力学特征，进行了野外调查和室内试验，包括显微镜观察、X射线粉末衍射分析和单轴压缩试验。通过对2个泥质砂岩、1个红泥岩、1个灰岩和1个砂岩岩样的采集和分析，综合考虑尺寸效应和时间效应，对三峡库区边坡的长期稳定性进行了研究。通过对以往滑坡的表观摩擦力和名义尺寸的分析，估计了滑坡的尺寸效应。关于斜坡崩塌或滑坡的时间依赖性是众所周知的。基于滑坡的尺寸效应和时间依赖性，计算了滑坡的超设计系数，并提出了三峡库区滑坡的防治措施。通过对7种不同岩石类型和试验条件的单轴压缩试验，发现岩石类型和试验参数均影响岩石在荷载作用下产生的电磁辐射特性。单轴压缩试验中应力降越大，电磁波的幅值越大。

In this study, estimation of large landslide around the Yangtze River was conducted. In order to study the geological setting and the mechanical characteristic of the landslide area around the Three Gorges reservoir, field investigation and laboratory work including microscope observation, X-ray powder diffraction analysis and uniaxial compressive tests have been carried out. Rock specimens such as two muddy sandstones, a red mudstone, a limestone and a sandstone were collected and examined.Long-term slope stability around the Three Gorges reservoir was discussed considering both size effect and time dependency. The size effect was estimated by data analysis of apparent friction and nominal dimension of landslides occurred in the past. Time dependency concerning slope collapse or landslide is well known. Based on the size effect and the time dependency, 'overdesign factor' was calculated to evaluate the risk of landslide and the control method for landslide around the Three Gorges area was proposed. It is thought that the results will be important for the selection of residents' migration places and for the landslide prevention measures in the construction of dam.Through uniaxial compression tests of seven different rock types and test conditions, it was found that both the rock type and test parameters affect the behavior of electromagnetic radiation generated in rocks under load. The larger the stress drop occurred in uniaxial compression test is, the larger the amplitude of electromagnetic wave.