Lateral deformation and acoustic emission characteristics of dam bedrock under various river flow scouring rates

作者：Wei Chen, Jie Liu, Wei Liu, Wenqing Peng, Yanlin Zhao, Qiuhong Wu, Yuanzeng Wang, Wen Wan, Shengnan Li, Huihua Peng, Xian‐Tao Zeng, Xiaofan Wu, Yu Zhou, Senlin Xie · 发表于：Journal of Materials Research and Technology · 年份：2023 · DOI：10.1016/j.jmrt.2023.08.050 · 被引用次数：34 · 研究领域：Landslides and related hazards、Dam Engineering and Safety、Rock Mechanics and Modeling

To investigate the lateral deformation characteristics of dam bedrock scoured by river flow environments, standard specimens were prepared using cored sandstone from the barrage bedrock at the Sanhekou Water Conservancy Dam. The mechanical parameters, microstructure, and mineral fractions of the sandstones were analyzed after water scouring at five different rates (0, 200, 400, 600, and 800 mm·s-1) for 49 days. Scanning electron microscopy (SEM), electron energy spectroscopy (EDS), and X-ray diffraction (XRD) techniques were employed to track the changes. Laboratory tests including uniaxial compression, acoustic emission (AE), and digital image correlation (DIC) were conducted to elucidate the deformation damage mechanism of the scoured sandstones. The results indicate the following: (1) During the crack closure and compaction stage, the deformation of the rock samples primarily involves axial compression with minimal lateral deformation. However, as the crack propagates unstably and expands after the peak load, the lateral strain of the specimens accelerates. The lateral-axial ratio of the samples remains relatively low during the initial scouring period but increases rapidly after the first drop in axial stress until the end of the test. Higher scouring rates and longer durations weaken the strength and exacerbate the deformation of the sandstone. Under a flow rate of 800 mm·s-1, the elastic modulus decreases by 45.67%, while Poisson's ratio increases by 73.67%. (2) The aco...