Identifying the spatiotemporal characteristics of individual red bed landslides: a case study in Western Yunnan, China

Strata in red bed areas have typical characteristics of soft-hard interbedding and high sensitivity to water. Under the comprehensive action of internal stratigraphic structure and external hydrological factors, red bed landslides have highly complex spatiotemporal characteristics, presenting significant challenges to the prevention and control of landslide disasters in red bed areas, especially for slope and tunnel engineering projects. In this study, we applied an interdisciplinary approach combining small baseline subset interferometric synthetic aperture radar(SBAS-InSAR), deep displacement monitoring, and engineering geological surveying to identify the deformation mechanisms and spatiotemporal characteristics of the Abi landslide, an individual landslide that occurred in the red bed area of Western Yunnan, China. Surface deformation time series indicated that a basic deformation range developed by March 2020. Based on In SAR results and engineering geological analysis, the landslide surface could be divided into three zones: an upper sliding zone(US), a lower uplifted zone(LU), and a toe zone(Toe). LU was affected by the structure of the sliding bed with variable inclination. Using deep displacement curves combined with the geological profile, a set of sliding surfaces were identified between different lithology. The groundwater level standardization index(GLSI) and deformation normalization index(DNI) showed different quadratic relationships between US and LU. Verification using the Pearson correlation analysis shows that the correlation coefficients between model calculated results and measured data are 0.7933 and 0.7577, respectively, indicating that the DNI-GLSI models are applicable. A fast and short-lived deformation sub stage(ID-Fast) in the initial deformation stage was observed, and ID-Fast was driven by concentrated rainfall.

Application of A New Anchor Cable Mounting Rod in the Lower Soft Coal Seam of Splitting and Merging Coal

To obtain the deep displacement of the coal seam in the working face,multi-point displacements were installed in the coal seam, but the installation of multi-point displacement is differen tunder different geological conditions. This paper is based on the splitting and merging of 7_1 coal and 7_2 coal in Huaibei Mining(Group) Co., Ltd., and analyzes properties of the roof andcoal in the 7_2 coal of the lower coal seam of bifurcation area, and calculates the damage depth of the floor in the process of 7_1 coal mining. The multi-point displacement meter installation is often challenged by hole collapse, stuck pole and broken installation rod in 7_2 coal of the soft coal seam of bifurcation area, as a result, the base points can't be installed in the specified location. In view of this, this paper adopts a new anchor cable mounting rod which can install the whole base points to the specified location without stuck pole or broken mounting stem. All the basic displacement data can be obtained, and the law of mine pressure appearance in stope and tunnel can be accurately controlled, which can be used to maintain the stability of roadway and the safety of stope.