Slope deformation partitioning and monitoring points optimization based on cluster analysis

The scientific and fair positioning of monitoring locations for surface displacement on slopes is a prerequisite for early warning and forecasting.However,there is no specific provision on how to effectively determine the number and location of monitoring points according to the actual deformation characteristics of the slope.There are still some defects in the layout of monitoring points.To this end,based on displacement data series and spatial location information of surface displacement monitoring points,by combining displacement series correlation and spatial distance influence factors,a spatial deformation correlation calculation model of slope based on clustering analysis was proposed to calculate the correlation between different monitoring points,based on which the deformation area of the slope was divided.The redundant monitoring points in each partition were eliminated based on the partition's outcome,and the overall optimal arrangement of slope monitoring points was then achieved.This method scientifically addresses the issues of slope deformation zoning and data gathering overlap.It not only eliminates human subjectivity from slope deformation zoning but also increases the efficiency and accuracy of slope monitoring.In order to verify the effectiveness of the method,a sand-mudstone interbedded CounterTilt excavation slope in the Chongqing city of China was used as the research object.Twenty-four monitoring points deployed on this slope were monitored for surface displacement for 13 months.The spatial location of the monitoring points was discussed.The results show that the proposed method of slope deformation zoning and the optimized placement of monitoring points are feasible.

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.

Reservoir Regulation for Control of an Ancient Landslide Reactivated by Water Level Fluctuations in Heishui River,China

Due to the complex geological processes of Qinghai-Tibet Plateau,numerous deposits,especially the large-scale ancient landslide deposits,are characteristic features of the valleys incised in southwestern China.Intense water level fluctuations since 2011 in Maoergai Reservoir,China,registered the reactivation of Xierguazi ancient landslide,and presented a significant risk to neighboring facilities.Based on detailed field survey and drilling exploration,the landslide was divided into Zone A and Zone B,and other characterizations of landslide were studied as well.To precisely measure the extent of landslide displacement during filling and drawdown stage,surface displacement monitoring system was deployed on the landslide.The monitoring analyses data reveal that reservoir fluctuation is the dominant factor influencing landslide displacement,especially during drawdown stage.Moreover,a future sliding is anticipated in Zone A,while a creep had already existed in Zone B.A reservoir regulation was then established using the lead-lag correlation between reservoir fluctuation and landslide displacement and landslide stability analysis.In the end,the follow-up deformation monitoring demonstrates that the reservoir regulation controlled the landslide effectively.Landslide control by reservoir regulation in Maoergai can serve as a case study for other settlements involved in similar construction activities.