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Abstract Five new toosendanin limonoids with highly oxidative furan ring walsurobustones A-D (1–4), and one new furan ring degraded limonoid walsurobustone E (5) together with one known compound toonapubesic acid B (6) were isolated from the leaves of Walsura robusta. Their structures were elucidated by NMR and MS data. Especially, the absolute configuration of toonapubesic acid B (6) was confirmed by X-ray diffraction study. Compounds 1–6 exhibited good cytotoxicity against the cancer cell lines HL-60, SMMC-7721, A-549, MCF-7, and SW480.

The dry beach length determines the hydraulic boundary of tailings impoundments and significantly impacts the infiltration line, which is crucial for the tailings dam. A deep learning method utilizing satellite images is presented to recognize the dry beach area and accurately measure the length of dry beaches in tailing ponds. Firstly, satellite images of various tailing ponds were gathered and the collection was enlarged to create a dataset of satellite images of tailing ponds. Then, a deep learning method was created using YOLOv5-seg to identify the dry beach area of tailing ponds from satellite images. The mask of the dry beach region was segmented and contour extraction was then carried out. Finally, the beach crest line was fitted based on the extracted contour. The pixel distance between the beach crest line and the dry beach boundary was measured and then translated into real distance by ground resolution. This paper's case study compared the calculated length of dry beach with the real length obtained by field monitoring. The results of the case study showed that the minimum error of the method was 2.10%, the maximum error was 3.46%, and the average error was 2.70%, indicating high precision for calculating dry beach length in tailing ponds. [ABSTRACT FROM AUTHOR]

The drain pipe wrapped in steel wire mesh serves a dual purpose of drainage and reinforcement in tailings pond projects. The self-filtering layer that develops upstream of the steel wire mesh influences the reinforcement characteristics of the drainage pipe. This study first conducts interfacial shearing experiments to explore the impact of the self-filtering layer on the shearing properties between tailings and the steel wire mesh. An exponential interface constitutive model is then proposed to delineate the shear stress–displacement relationship. Finally, through finite element simulations, the study assesses the effect of the self-filtering layer on the load-bearing behavior of the drain pipe, considering the interactive dynamics between the tailings and the steel wire mesh. The results reveal that the interfacial shear strength, across varying median particle sizes of the self-filtering layer, adheres to Mohr–Coulomb strength theory. Specifically, as the median particle size of the self-filtering layer increases, interfacial cohesion diminishes while the friction coefficient rises. The initial shear stiffness demonstrates a linear increase with the median particle size. With the presence of the self-filtering layer, the pull-out resistance of the drainage pipe can be enhanced by up to 26%. Moreover, the self-filtering layer significantly affects the distribution of negative skin friction. This research enhances the safety assessment of tailings ponds by providing crucial insights and solutions, emphasizing the influence of the self-filtering layer on the bearing behavior of the drain pipe. [ABSTRACT FROM AUTHOR]

In light of the engineering characteristics of fine-grained tailings, such as their high moisture content, high compressibility, difficult deposition, and difficult consolidation, and based on the summary and analysis of the experience of tailing dam construction in China and abroad, a new comprehensive treatment technology suitable for dam construction on a weak beach, which is composed of strengthening foundation with the soilbag, subdam stabilization, and collaborative drainage, is proposed. Taking a dam construction project on the weak beach of a tailing pond in China as the research object and through the study of the reinforcement mechanism of the soft beach treated using the soilbag method, it can be seen that the soilbag body has the mechanism of strength growth by sand fixation and water permeability and constraint formation and can achieve an overall stable effect of extrusion and silt replacement, stacking and surcharge, and flexible embedding in a weak beach. Using this method, combined with relevant monitoring technology, a good demonstration of dam construction speed of up to 30 m/a and a safe dam construction height of up to 60 m on a weak beach surface is achieved in a tailing dam construction project, which provides a good reference for the design and construction of fine tailing dam engineering and the cooperative disposal of adverse geological conditions.