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Sliding and damming properties of granular debris with different geometric configurations and grain size distributions

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Journal of Mountain Science 2024年第3期21卷 932-951页

作者： HE Ligeng TAN Longmeng yang xingguo ZHOU Jiawen LIAO Haimei College of Civil Engineering Guizhou UniversityGuiyang 550025China Quality Supervision and Law Enforcement Detachment of Guizhou Province Traffic Construction Engineering Guiyang 550081China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China

Granular debris plays a significant role in determining damming deposit characteristics. An indepth understanding of how variations in grain size distribution(GSD) and geometric configurations impact the behavior of granular debris during the occurrence of granular debris is essential for precise assessment and effective mitigation of landslide hazards in mountainous terrains. This research aims to investigate the impact of GSD and geometric configurations on sliding and damming properties through laboratory experiments. The geometric configurations were categorized into three categories based on the spatial distribution of maximum volume: located at the front(Type Ⅰ), middle(Type Ⅱ), and rear(Type Ⅲ) of the granular debris. Our experimental findings highlight that the sliding and damming processes primarily depend on the interaction among the geometric configuration, grain size, and GSD in granular debris. Different sliding and damming mechanisms across various geometric configurations induce variability in motion parameters and deposition patterns. For Type Ⅰ configurations, the front debris functions as the critical and primary driving component, with energy dissipation primarily occurring through inter-grain interactions. In contrast, Type Ⅱ configurations feature the middle debris as the dominant driving component, experiencing hindrance from the front debris and propulsion from the rear, leading to complex alterations in sliding motion. Here, energy dissipation arises from a combination of inter-grain and grain-substrate interactions. Lastly, in Type Ⅲ configurations, both the middle and rear debris serve as the main driving components, with the rear sliding debris impeded by the front. In this case, energy dissipation predominantly results from grainsubstrate interaction. Moreover, we have quantitatively demonstrated that the inverse grading in damming deposits, where coarse grain moves upward and fine grain moves downward, is primarily caused by grain sortin

关键词： Landslide dam Geometric configuration Energy dissipation Inverse grading Physical experiment

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堰塞坝溃决参数及其寿命预测

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水利学报 2024年第3期55卷 367-377页

作者：冯震宇杨兴国周家文廖海梅贵州大学土木工程学院贵州贵阳550025 四川大学水力学与山区河流开发保护国家重点实验室成都四川610065

堰塞坝溃决洪水对下游影响区域的人民生命财产、基础设施以及生态环境构成严重威胁,提高堰塞坝溃决参数及其寿命预测的准确度是应急处置的迫切需求。本文对全球1957组堰塞坝案例分别进行地理、统计学分析,在得到溃决参数主要影响因素的... 详细信息

堰塞坝溃决洪水对下游影响区域的人民生命财产、基础设施以及生态环境构成严重威胁,提高堰塞坝溃决参数及其寿命预测的准确度是应急处置的迫切需求。本文对全球1957组堰塞坝案例分别进行地理、统计学分析,在得到溃决参数主要影响因素的基础上,选取数据库中拥有完整信息的48组案例,利用非线性回归方法分别建立了洪峰流量、破坏深度、溃口顶宽、溃口底宽和溃决时长的预测模型,其均具有较高的拟合程度。之后分析了堰塞坝溃决参数的敏感性,结果显示坝高对溃决过程有显著影响。此外,基于19组寿命信息充分的案例,使用不同自变量和算法分别建立了蓄水阶段持续时间、溢流阶段持续时间的预测模型,并采用加权融合法提出了相应的融合模型。该成果可为量化评估堰塞坝溃决过程参数和寿命预测提供参考。

关键词：堰塞坝溃决参数寿命分析预测模型

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Spatial distribution and failure mechanism of water-induced landslides in the reservoir areas of Southwest China

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第2期15卷 442-456页

作者： Mingliang Chen xingguo yang Jiawen Zhou State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu610065China College of Water Resources and Hydropower Sichuan UniversityChengdu610065China

Water-induced landslides in hydropower reservoirs pose a great threat to both project operation and human *** paper examines three large reservoirs in Sichuan Province,*** surveys,site monitoring data analyses and numerical simulations are used to analyze the spatial distribution and failure mechanisms of water-induced landslides in reservoir ***,the general rules of landslide development in the reservoir area are *** first rule is that most of the landslides have rear edge elevations of 100e500 m above the normal water level of the reservoir,with volumes in the range of 106 e107 m *** the volume exceeds a certain amount,the number of sites at which the landscape can withstand landslides is greatly *** hazards mainly occur in the middle section of the reservoir and less in the annex of the dam site and the latter half of the reservoir *** second rule is that sedimentary rocks such as sandstone are more prone to landslide hazards than other ***,the failure mechanism of changes in the water level that reduces the stability of the slope composed of different geomaterials is analyzed by a proposed slope stability framework that considers displacement and is discussed with the monitoring *** is an essential parameter for understanding the diametrically opposed deformation behavior of landslides experiencing filling-drawdown cycles during *** study seeks to provide inspiration to subsequent researchers,as well as guidance to technicians,on landslide prevention and control in reservoir areas.

关键词： Water-induced landslide Hydropower reservoir Spatial distribution Fundamental control Failure mechanism

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应用糖皮质激素治疗进展期胸腺瘤的有效性分析

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中华胸心血管外科杂志 2024年第1期40卷 24-27页

作者：杨兴国于磊于涛余振杜鑫高翔于鑫韬首都医科大学附属北京同仁医院胸外科北京100730

目的探讨中等剂量糖皮质激素治疗进展期胸腺瘤的临床疗效和安全性。方法回顾性分析2018年1月至2023年3月期间在首都医科大学附属北京同仁医院接受糖皮质激素(醋酸泼尼龙)治疗的56例胸腺瘤患者的临床资料,其中男33例,女23例;年龄28~72岁... 详细信息

目的探讨中等剂量糖皮质激素治疗进展期胸腺瘤的临床疗效和安全性。方法回顾性分析2018年1月至2023年3月期间在首都医科大学附属北京同仁医院接受糖皮质激素(醋酸泼尼龙)治疗的56例胸腺瘤患者的临床资料,其中男33例,女23例;年龄28~72岁,平均(43.8±11.2)岁。B1型胸腺瘤16例,B2型23例,B3型17例。合并重症肌无力17例,合并纯红细胞再生障碍1例。所有患者均曾接受过放疗或化疗,但未见明显改善。患者接受中等剂量糖皮质激素50 mg/天治疗,治疗2周后行胸部CT检查评估肿瘤反应,记录肿瘤治疗效果和不良反应。结果全组56例患者,部分缓解22例,完全缓解3例,总体客观缓解率44.6%(25/56)。其中,23例B2型胸腺瘤患者,部分缓解17例,完全缓解3例,客观缓解率87.0%(20/23);16例B1型胸腺瘤患者,部分缓解5例;17例B3型胸腺瘤患者均无疗效。随访患者2~26个月,2例出现胸腺瘤复发。结论中等剂量糖皮质激素治疗晚期或侵袭性胸腺瘤安全有效,尤其适用于B2型胸腺瘤的治疗。

关键词：胸腺瘤肿瘤糖皮质激素

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Effects of Material Composition and Water Content on the Mechanical Properties of Landslide Deposits Triggered by the Wenchuan Earthquake

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Acta Geologica Sinica(English Edition) 2016年第1期90卷 242-257页

作者： ZHOU Jiawen CUI Peng yang xingguo State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Key Laboratory of Mountain Hazards and Surface Process Chinese Academy of Sciences College of Water Resource and Hydropower Sichuan University

Abundant landslide deposits were triggered by the Wenchuan earthquake, providing a rich source of material for subsequent debris flows or slope failures under rainfall conditions. A good understanding of the physical and mechanical properties of the landslide deposits is very important to the research on slope failure mechanisms and the initiation of debris flow. Laboratory biaxial compression tests are used to study the material compositions and water content impacts on the mechanical properties of landslide deposits, and a discrete element method （a bond-contact model） is used to study the particle stiffness, bond force, friction coefficient and confining stress impact on the mechanical behaviors and the relationships between the numerical and experimental parameters. The experimental results show that the failure stress of landslide deposits is decreased with increasing content of fine particles and also with increased water content, especially at the initial increasing stage. Cohesion of the saturated landslide deposits is increased, but the friction angle is decreased with the increase in the fine particle content. Shear strength parameters （the cohesion and friction angle） are decreased with the increasing water content at the initial increasing stage, and then, they slowly decrease. There is a critical value of the water content at 5%-7% （in weight） for the failure stress and shear strength parameters of the landslide deposits. Quadratic equations are presented to describe the relation between the bond force and cohesion, and the numerical friction coefficient and the experimental friction angle.

关键词： landslide deposits particle size distribution water content shear strength parameters numerical modeling

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高温作用后的北山花岗岩时效变形特征研究

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吉林水利 2024年第3期 1-7页

作者：罗星杨兴国鲁功达四川大学水力学与山区河流开发保护国家重点实验室四川成都610065 四川大学水利水电学院四川成都610065 成都理工大学地质灾害防治与地质环境保护国家重点实验室四川成都610059

以甘肃高放废物重点预选场址的北山花岗岩为研究对象,开展不同热损伤和围压条件下的三轴分级蠕变试验,分析热力耦合作用下的北山花岗岩蠕变变形机理。试验结果表明,在单轴条件下,北山花岗岩的微裂纹密度随热处理温度升高而逐渐增加,进... 详细信息

以甘肃高放废物重点预选场址的北山花岗岩为研究对象,开展不同热损伤和围压条件下的三轴分级蠕变试验,分析热力耦合作用下的北山花岗岩蠕变变形机理。试验结果表明,在单轴条件下,北山花岗岩的微裂纹密度随热处理温度升高而逐渐增加,进而导致轴向峰值应变持续增大。150℃和300℃温度荷载造成的轻微热开裂引发了裂纹尖端钝化,从而增强了热损伤花岗岩的长期强度;当热处理温度达到600℃后,石英相变产生的差异性热膨胀导致北山花岗岩的热裂纹密度显著增加,进而造成长期强度急剧降低。相比之下,在5 MPa和25 MPa围压的三轴蠕变试验中,静水压力能够愈合较低温度荷载造成的热开裂,使150℃和300℃热损伤花岗岩的轴向峰值变形和长期强度恢复至无损岩石水平。然而,上述静水压力未能完全愈合600℃热处理温度造成的热开裂,热损伤花岗岩的残余微裂纹导致轴向峰值应变增大,并造成了裂纹尖端的钝化效应,最终导致北山花岗岩的长期强度增大。

关键词：北山花岗岩热损伤围压蠕变试验长期强度

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不同粒组含量下堰塞坝溃决过程的试验研究

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水利水电技术（中英文） 2024年第5期55卷 29-37页

作者：李楠杨兴国周家文焦煦李付华廖海梅贵州大学土木工程学院贵州贵阳550025 四川大学水力学与山区河流开发保护国家重点实验室四川成都610065

【目的】堰塞坝结构松散、颗粒级配范围宽,易发生漫顶溃决,严重威胁上下游人民的生命财产安全。为进一步探究相同粒径范围内不同粒组含量条件下堰塞坝的溃决过程,【方法】以“11.3”金沙江白格堰塞坝为参考原型,开展了溃决模型水槽试验... 详细信息

【目的】堰塞坝结构松散、颗粒级配范围宽,易发生漫顶溃决,严重威胁上下游人民的生命财产安全。为进一步探究相同粒径范围内不同粒组含量条件下堰塞坝的溃决过程,【方法】以“11.3”金沙江白格堰塞坝为参考原型,开展了溃决模型水槽试验。【结果】结果显示,堰塞坝的溃决过程可以划分为渗流与过流、溯源侵蚀、溃口发展及衰减平衡四个阶段。溃口流速与溃决流量均呈现先增大后减小的过程,但峰值流量滞后于峰值流速。另外,溃决水流冲击力在溃口发展阶段持续增大,在衰减平衡阶段开始下降,而水流重度在溃口发展阶段表现出一定范围内的波动。随着中值粒径的增大,溃决流量峰值减小、峰现时间延迟、溃决水流冲击力峰值减小,下游泥沙淤积区长度变短、厚度变大。【结论】研究结果进一步揭示了相同粒径范围内的不同粒组含量对堰塞坝稳定性、溃决过程和溃决参数的影响,可为堰塞坝灾害的风险评估和应急处置提供参考。

关键词：堰塞坝粒组含量溃决过程峰值流量水流特征风险评估

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Stability analysis of surrounding rock mass in underground powerhouse considering damage effect of microfractures

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第4期14卷 1115-1130页

作者： Peiwei Xiao Haoyu Mao Bo Qian Biao Li xingguo yang Nuwen Xu State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China Guodian Jinshajiang Xulong Hydropower Development Co. LtdChengdu610041China School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500China

A high-precision microseismic(MS)monitoring system was built to monitor surrounding rock microfractures in the underground powerhouse on the left bank of Shuangjiangkou Hydropower *** surrounding rock damage area with spatiotemporal clustering of MS activities was studied for qualitative analysis of the damage mechanism of surrounding rock microfractures,based on the source parameters of MS *** surrounding rock microfracture scale characterized by the source radius of MS events was considered to establish the constitutive *** information was imported into the model for numerical analysis using fast Lagrangian analysis of continuain 3 dimensions(FLAC^(3D)).The results indicated that the numerical simulation results considering MS damage can better reflect the actual situation of the *** surrounding rock microfractures mainly showed mixed failure *** failures appeared in localized areas while the fracture scale of sections from K0e33 m to K0e15 m on the vault was *** deformation increment caused by microfracture damage in the shallow surrounding rock of the top arch accounted for 10%e13%,and the stress decrement in the surrounding rock caused by microfracture damage accounted for about 10%.

关键词： Underground powerhouse Microseismic(MS)monitoring Numerical modeling Microfracture damage Constitutive relation

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某堰塞坝冲刷溃决数值模拟分析

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水利规划与设计 2024年第3期 105-110页

作者：吕霞杨兴国范刚林子钰刘大瑞四川大学水利水电学院四川成都610065 四川大学水力学与山区河流开发保护国家重点实验室四川成都610065

堰塞坝发生溃决破坏会严重威胁下游人民的安全。为降低其对下游的威胁,文章以黑西洛沟滑坡-泥石流-堰塞湖灾害为例,通过Flow-3D软件对坝体溃决过程进行模拟,得到流速特征及溃口冲淤情况。结果表明:泄流过程中,溃口逐步扩展,坝体下游出... 详细信息

堰塞坝发生溃决破坏会严重威胁下游人民的安全。为降低其对下游的威胁,文章以黑西洛沟滑坡-泥石流-堰塞湖灾害为例,通过Flow-3D软件对坝体溃决过程进行模拟,得到流速特征及溃口冲淤情况。结果表明:泄流过程中,溃口逐步扩展,坝体下游出现侵蚀破坏,随后溃口向上游发展;泄流槽末端最大流速达到17.5m/s,溃口迅速下切,冲刷深度达25.7m。坝体下游出现淤积,淤积高度达8.4m。溃决过程中,跌坎不断向上移动,发生溯源侵蚀。研究成果有助于深入分析黑西洛堰塞坝溃决过程及机理,为今后处置堰塞体提供支持。

关键词：堰塞坝数值模拟冲刷溃决漫顶

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Microseismic monitoring and forecasting of dynamic disasters in underground hydropower projects in southwest China:A review

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第8期15卷 2158-2177页

作者： Biao Li Nuwen Xu Peiwei Xiao Yong Xia Xiang Zhou Gongkai Gu xingguo yang School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China Power China Chengdu Engineering Co. LtdChengdu610072China Chn Energy Dadu River Hydropower Development Co. LtdChengdu610041China China Three Gorges Construction Engineering Corporation Chengdu610095China

The underground hydropower projects in Southwest China is characterized by large excavation sizes,high geostresses,complicated geological conditions and multiple construction *** disasters such as collapses,large deformations,rockbursts are frequently encountered,resulting in serious casualties and huge economic *** review mainly presents some representative results on microseismic(MS)monitoring and forecasting for disasters in hydropower underground ***,a set of new denoising,spectral analysis,and location methods were developed for better identification and location of MS ***,the tempo-spatial characteristics of MS events were analyzed to understand the relationship between field construction and damages of surrounding *** with field construction,geological data,numerical simulation and parametric analysis of MS sources,the focal mechanism of MS events was revealed.A damage constitutive model considering MS fracturing size was put forward and feedback analysis considering the MS damage of underground surrounding rocks was ***,an MS multi-parameter based risk assessment and early warning method for dynamic disasters were *** technology for control of the damage and deformation of underground surrounding rocks was proposed for underground ***,two typical underground powerhouses were selected as case *** achievements can provide significant references for prevention and control of dynamic disasters for underground engineering with similar complicated geological conditions.

关键词： MS monitoring Forecasting method Control technology Dynamic disaster Underground engineering

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