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Analysis on the failure mechanism and entire evolution process of toppling bank slope under heavy rainfall utilizing material point method

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ENGINEERING GEOLOGY 2025年 347卷

作者： Su, Chao Che, Ailan Zhou, Jifang Xie, Guoquan Shanghai Jiao Tong Univ Sch Ocean & Civil Engn 800 Dongchuan Rd Shanghai 200240 Peoples R China Shanghai Jiao Tong Univ Sichuan Res Inst Chengdu 610213 Peoples R China Yalong River Hydropower Dev Co Ltd Chengdu 610056 Peoples R China

The Yalong River hydropower base is located on the eastern margin of Tibet Plateau, where the toppling slopes are widely distributed. The toppling slopes are susceptible to sliding during rainfall, posing a significant safety risk to hydroelectric generating. Examining the kinematic properties and disaster effects of potential landslides is crucial for assessing risks and the safety management of reservoirs, as well as understanding the failure mechanism of toppling slopes. Tiangeng slope is a toppling bank slope situated in the middle reaches of Yalong River, and its deformation mode is representative of the region. To facilitate disaster mitigation and early warning in reservoir area, the Tiangeng slope is analyzed by the integration of field monitoring and material points method (MPM). Additionally, the MPM results are compared with the finite element method (FEM), thereby confirming the reliability of MPM. The essential information such as slope deformation trend and potential sliding surface are obtained by field monitoring, which provides a basis for establishing the numerical model. The MPM is an efficient numerical technique for examining geotechnical nonlinear large deformation issues. The MPM is utilized to investigate the entire evolution process of slope failure under rainfall, emphasizing the post-landslide stage. The results show that the slope exhibits typical toppling-slip deformation, with the principal failure characteristic being creep-tension cracking. The potential slope failure exhibits retrogression and traction characteristics, comprising four distinct stages and a maximum runout distance of 202.9 m.

关键词： Landslide Rainfall Toppling Material point method evolution process

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Nitrogen and phosphorus evolution process and driving mechanisms of three major freshwater lakes with different river-lake connectivity (DRLC) in the lower reaches of the Yangtze river, the largest river in Asia

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JOURNAL OF CLEANER PRODUCTION 2025年 486卷

作者： Wang, Cong Wang, Xihua Xu, Y. Jun Lv, Qinya Ji, Xuming Jia, Shunqing Liu, Zejun Mao, Boyang Tongji Univ Coll Civil Engn 1239 Siping Rd Shanghai 200092 Peoples R China Univ Waterloo Dept Earth & Environm Sci Waterloo ON N2L 3G1 Canada Louisiana State Univ Agr Ctr Sch Renewable Nat Resources Baton Rouge LA USA

The river-lake connectivity (RLC) might affect the nitrogen and phosphorus cycle of lakes by controlling water exchange between large rivers and lakes, however, the role of RLC in the nitrogen and phosphorus evolution of lakes is still poorly understood. Here, we explored the dynamics and driving mechanisms of nitrogen and phosphorus across three major freshwater lakes with different RLC (DRLC) in the lower reaches of the Yangtze River through the Modified Mann-Kendall test, Entropy-weighted water quality index, and multivariate statistical analysis methods. Our results showed that NO3--N and NO2--N in the high RLC lake (Poyang Lake, PYL) exhibited a significantly increasing trend along with water quality deterioration (Z = 2.4312 & lowast;P = 0.0075 < 0.05), whereas TN, NO3--N, NH3-N, and NO2--N in the low RLC lakes (Chaohu Lake, CHL;Taihu Lake, THL) exhibited a significantly decreasing trend along with water quality improvement. The pollution sources of the lakes were all dominated by external loads, and the continued water quality deterioration in PYL might be attributed to hydrologic conditions change and pollution loads increase. Differently from low RLC lakes, there was no significant spatial heterogeneity in nitrogen and phosphorus of PYL due to strong hydrodynamic mixing. Nitrogen and phosphorus were major contributors to water quality variation in high and low RLC lakes, respectively, controlled by hydrologic conditions and the biogeochemical behavior of nitrogen and phosphorus. An average of 58.2% of TN/TP in three lakes were in the range optimal for phytoplankton growth (10

关键词： Nitrogen and phosphorus evolution process Driving mechanism Lakes River-lake connectivity

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evolution process of the synthesis of TiC in the Cu-Ti-C system

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JOURNAL OF ALLOYS AND COMPOUNDS 2008年第2期452卷 298-303页

作者： Liang, Y. H. Wang, H. Y. Yang, Y. F. Wang, Y. Y. Jiang, Q. C. Jilin Univ Minist Educ Key Lab Automobile Mat Changchun 130025 Peoples R China Jilin Univ Dept Mat Sci & Engn Changchun 130025 Peoples R China

The evolution process of TiC formation in the 20 wt.% Cu-Ti-C powder mixtures was studied by using differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The TixCuy compounds (Ti2Cu, TiCu, Ti3Cu4 and TiCu4) formed initially via solid-state diffusion reactions between Cu and Ti particles;and then TiCu and TiCu can form a Cu-Ti eutectic liquids at about 1233 K. The unreacted Ti and C particles dissolved into the Cu-Ti liquids and led to the formation of Cu-Ti-C ternary liquids;subsequently, TiC particulates precipitated out of the saturated liquids. At the same time, also the formation of TiCu occurred at the interface between the Cu-Ti liquids and the unreacted Ti particles. As the temperature increased further, the Ti,Cu melted and more Cu-Ti liquids formed;and then C particles continuously dissolved into the Cu-Ti-C liquids and TiC particulates gradually precipitated out of the saturated liquids. (c) 2006 Elsevier B.V. All rights reserved.

关键词： titanium carbide differential thermal analysis copper evolution process

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evolution process and regulation of particle kinematics and spatial distribution driven by exciting parameters during variable-amplitude screening

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POWDER TECHNOLOGY 2018年 330卷 292-303页

作者： Jiang, Haishen Qiao, Jinpeng Zhao, Yuemin Duan, Chenlong Luo, Zhenfu Liu, Chusheng Yang, Yongzhu He, Jingfeng Zhao, Lala Pan, Miao China Univ Min & Technol Key Lab Coal Proc & Efficient Utilizat Minist Educ Xuzhou 221116 Peoples R China China Univ Min & Technol Sch Mechatron Engn Xuzhou 221116 Peoples R China Anshan Heavy Min Machinery Co LTD Anshan 114051 Peoples R China

Variable-amplitude screen has been widely used for the classification of particulate materials due to its advantages including large capacity production and good screening performance. The exciting parameters significantly influence the trajectory of the screen surface, particle kinematics and spatial distribution, and screening performance during variable-amplitude screening. Investigation of the optimization and regulation of exciting parameters is necessary because they are the key to realize high screening efficiency of materials. In this study, variable-amplitude screening experiment and test analysis system were constructed to conduct relevant research. Consequently, the material distribution on the screen surface exhibited the spatial evolution process as follows: the material layer was thicker at the feed end, had approximately equal thickness of the material layer, and a thicker material layer at the discharge end with an increasing difference in amplitude. The corresponding screening efficiency first increased and then decreased. Based on the above-mentioned analysis, the method of regulation of trajectory of screen, particle velocity, and material distribution during variable-amplitude screening by adjusting exciting parameters was introduced to realize the variable amplitude equal-thickness screening and achieve optimum classification performance. Based on the proposed regulation method, the optimum conditions were obtained as follows: f(1) = 4.01 kN, f(2) = 3.09 kN, k(f) = 1.3, and I-reb = 40%;the corresponding screening efficiency reached a maximum value of 93.11%, and the total misplaced materials reached a minimum value of 2.68%. (C) 2018 Published by Elsevier B.V.

关键词： Variable-amplitude screening Particle velocity Spatial distribution evolution process Exciting parameters

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evolution process and Simulation of Advanced Equipment Manufacturing Innovation Network Based on Intelligent System

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BIG DATA 2022年第3期10卷 204-214页

作者： Wang, Jianbo Cao, Xing Cent South Univ Business Sch Changsha 410083 Peoples R China Hunan Univ Humanities Sci & Technol Loudi Peoples R China Hunan First Normal Univ Changsha Peoples R China

With the widespread application of intelligent systems in major industries, the traditional equipment manufacturing industry has gradually shifted to advanced equipment manufacturing. The innovation network of an industry directly affects the innovation capability of the industry, so the research of innovation network has always been the focus of attention. However, there are few researches on the innovation network of advanced equipment manufacturing industry, so this article has launched an in-depth study on it. First, it analyzes the basic geometric characteristics of the innovation network. Then, based on the small-world network model, an evolution model of the advanced equipment manufacturing innovation network was created, and simulation experiments were performed on the evolution model. The experimental results show that the clustering coefficient and the average distance showed different changes in different stages, but in the end they all gradually stabilized. The clustering coefficient was 0.484, the average distance was 1.854, and the degree of small cosmos was 0.497. This shows that the innovation network evolution model established in this study can reveal the evolution process of the innovation network of advanced equipment manufacturing through simulation experiments.

关键词： intelligent system advanced equipment manufacturing innovation network evolution process experimental simulation

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evolution process and sources of ambient volatile organic compounds during a severe haze event in Beijing, China

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SCIENCE OF THE TOTAL ENVIRONMENT 2016年 560卷 62-72页

作者： Wu, Rongrong Li, Jing Hao, Yufang Li, Yaqi Zeng, Limin Xie, Shaodong Peking Univ Coll Environm Sci & Engn State Key Joint Lab Environm Simulat & Pollut Con Beijing 100871 Peoples R China

108 ambient volatile organic compounds (VOCs) were measured continuously at a time resolution of an hour using an online gas chromatography-frame ionization detector/mass spectrometry (GC-FID/MS) in October 2014 in Beijing, and positive matrix factorization (PMF) was performed with online data. The evolution process and causes for high levels of VOCs during a haze event were investigated through comprehensive analysis. Results show that mixing ratios of VOCs during the haze event (89.29 ppbv) were 2 to 5 times as that in non-haze days, There was a distinct accumulation process of VOCs at the beginning of the haze event, and the mixing ratios of VOCs maintained at the high levels until to the end of pollution when the mixing ratios of ambient VOCs recovered to the normal concentration levels in a few hours. Some reactive and toxic species increased remarkably as well, which indicates a potential health risk to the public in terms of VOCs. Eight sources were resolved by PMF, and results revealed gasoline exhaust was the largest contributor (32-46%) to the ambient VOCs in Beijing. Emissions of gasoline exhaust surged from 13.46 to 40.36 ppbv, with a similar variation pattern to total VOCs, indicating that high levels of VOCs were largely driven to by expanded vehicular emissions. Emissions of biomass burning also increased noticeably (from 2.32 to 11.12 ppbv), and backward trajectories analysis indicated regional transport of biomass burning emissions. Our findings suggested that extremely high levels of VOCs during the haze event was primarily attributed to vehicular emissions, biomass burning and regional transport, as well as stationary synoptic conditions. (C) 2016 Elsevier B.V. All rights reserved.

关键词： VOCs Source apportionment Vehicular emissions Biomass burning evolution process

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Time-dependent evolution process of Sb_2Te_3 from nanoplates to nanorods and their Raman scattering properties

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Chinese Physics B 2016年第10期25卷 342-344页

作者：孟秀清汤宁钟绵增叶慧群方允樟 Zhejiang Provincial Key Laboratory of Solid State Optoelectronic Devices Zhejiang Normal University State Key Laboratory of Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences

High-quality SbTenanostructures are synthesized by a simple hydrothermal method. The morphologies of the nanostructures change from hexagonal nanoplates to nanorods with the extension of growth time. Secondary nucleation is the dominant factor responsible for the change of the morphologies. Structural analyses indicate that all the obtained nanostructures are well crystallized. IR-active phonons are mainly observed in the Raman spectra of the nanoplates and nanorods. The slight deviations are observed in the Raman modes between the nanoplates and nanorods, which could originate from confinement effect in the nanostructures.

关键词： Sb_2Te_3 nanostructures evolution process confinement effect

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Analysis on the evolution process of BFW-like model with discontinuous percolation of multiple giant components

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PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS 2013年第5期392卷 1232-1245页

作者： Zhang, Renquan Wei, Wei Guo, Binghui Zhang, Yang Zheng, Zhiming Beihang Univ LMIB Beijing 100191 Peoples R China Beihang Univ Sch Math & Syst Sci Beijing 100191 Peoples R China

Recently, the modified BFW model on random graphs [W. Chen, R.M. D'Souza, Phys. Rev. Lett. 106 (2011) 115701], which shows a discontinuous percolation transition with multiple giant components, has attracted much attention from physicists and statisticians. In this paper, by establishing the evolution equations on the modified BFW model, the evolution process and steady-states on both random graphs and finite-dimensional lattices are analyzed. On a random graph, by varying the edge accepted rate a, the system stabilizes in a steady-state with different numbers of giant components. Moreover, a close correspondence is built between the values of a and the number of giant components in steady-states, the efficiency of which is verified by the numerical simulations. Then, the sizes of giant components for different evolution strategies can be obtained by solving some constraints derived from the evolution equations. Meanwhile, a similar analysis is expanded to finite-dimensional lattices, and we find the BFW (alpha) model on a finite-dimensional lattice has different steady-states from those on a random graph, but they have the same evolution mechanism. The analysis of the evolution process and steady-state is of great help to explain the properties of discontinuous percolation and the role of nonlocality. (C) 2012 Elsevier B.V. All rights reserved.

关键词： Discontinuous percolation BFW model Multiple giant components evolution process

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Triggering mechanism and possible evolution process of the ancient Qingshi landslide in the Three Gorges Reservoir

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GEOMATICS NATURAL HAZARDS & RISK 2021年第1期12卷 3160-3174页

作者： Wang, Luqi Zhang, Zhihua Huang, Bolin Hu, Mingjun Zhang, Chenyang Chongqing Univ Sch Civil Engn Chongqing Peoples R China Chongqing 208 Geoenvironm Res Inst Co Ltd Chongqing Peoples R China China Three Gorges Univ Hubei Key Lab Disaster Prevent & Mitigat Yichang Peoples R China China Univ Geosci Fac Engn Wuhan Peoples R China

The Qingshi landslide in the Three Gorges Reservoir was selected as a case study of ancient landslides. The detailed on-site surveys and long-term monitoring data were analysed to classify the triggering mechanism and possible evolution process of the Qingshi landslide. The results show that the ancient Qingshi landslide was triggered by the water storage in 2010. The leading edge slipped first, and the trailing edge underwent large-scale deformation after losing the resistance provided by the leading edge. In early 2011, the compaction of the leading edge of the landslide provided a certain resisting force, which controlled the overall downward movement of the landslide. In 2014, the integrity of the landslide was strengthened by emergency treatment measures, which caused the stabilization of the landslide and further reduced the displacement rate of the landslide. The local strengthening of the leading edge may act as a locking segment that could provide direct support to the sections in the middle and upper parts of the landslide. However, abnormal water-level regulation and heavy rainfall may cause the landslide to collapse again. The entire evolution process of the Qingshi landslide can provide an important reference for ancient landslides located on reservoir banks.

关键词： Reactivation of ancient landslides the Three Gorges Reservoir deep-seated landslide evolution process

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Rainfall-Mining Coupling Effects on Slope Failure Mechanism and evolution process: A Case Study of Open-Pit to Underground Mining

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WATER 2024年第5期16卷 740页

作者： Li, Qihang Wang, Yunmin Li, Xiaoshuang Gong, Bin Changzhou Univ Sch Urban Construct Changzhou 213164 Peoples R China Chongqing Univ Sch Resources & Safety Engn Chongqing 400044 Peoples R China Sinosteel Maanshan Gen Inst Min Res Co Ltd Maanshan 243000 Peoples R China Shaoxing Univ Sch Civil Engn Shaoxing 312000 Peoples R China Brunel Univ London Coll Engn Design & Phys Sci London UB8 3PH England

This research examines how rainfall and mining affect the slope damage resulting from the transition from open-pit mining to underground mining. Using an unmanned aerial vehicle (UAV), the Huangniu slope of the Dexing Copper Mine was fully characterized, and experiments were conducted on rock samples from appropriate sites. First, the mechanical properties of the samples were measured. Then, the parameters of the similarity simulation experiments were derived based on the similarity theory. Subsequently, the rainfall, rock slope, data acquisition, and monitoring systems were designed. Finally, the rock mass failure with different slope angles was analyzed, and the deformation and damage patterns under the coupling effect were obtained. The results show that rainfall increases pore water pressure and moisture content. Rainfall and slope-slip water have more of an impact on the open-pit platform. The pore water pressure values on the upper rock mass rise faster than inside it. In the open-pit mining stage, the rock mass shifts slightly to the upper left. In the room mining stage, vertical fractures and goaf sinking occur. The fractures above the mine form a semi-ellipse. In the pillar mining stage, overlying rock displacement is evident and fractures persist. In the continuous pillar mining stage, the overlying rock collapses. The 65 degrees slope model was the most damaged, while the 55 degrees slope model was the least damaged. The results also suggest that the UAV guides sample selection.

关键词： rainfall and mining coupling open-pit to underground mining rock slope failure mechanism evolution process similarity simulation experiment

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