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工程科学与技术:2021,53(6):21-32
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堰塞体状态相关剪胀理论与坝体溃决演化规律研究构想
(1.南京水利科学研究院 岩土工程研究所,江苏 南京 210024;2.水利部水库大坝安全重点实验室,江苏 南京 210029;3.南京水利科学研究院 河流海岸研究所,江苏 南京 210024;4.河海大学 土木与交通学院,江苏 南京 210098)
Research Framework of the State-dependent Dilatancy Theory and Breach Evolution Law of Landslide Dam
(1.Geotechnical Eng. Dept., Nanjing Hydraulic Research Inst., Nanjing 210024, China;2.MWR Key Lab. of Reservoir Dam Safety, Nanjing 210029, China;3.River Harbor Eng. Dept., Nanjing Hydraulic Research Inst., Nanjing 210024, China;4.College of Civil and Transportation Eng., Hohai Univ., Nanjing 210098, China)
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投稿时间:2021-06-29    修订日期:2021-10-19
中文摘要: 堰塞体一般在自然力作用下瞬间形成,堆积体具有空间结构复杂、坝料级配宽泛、稳定性差、易在水流冲刷下发生溃决等特点。堰塞体作为一种重大的水旱自然灾害,其安全评价和灾害预测是国内外学者关注的焦点,目前尚有很多问题需要解决,包括:1)堆积体由天然宽级配土石料构成,表现出显著的状态相关性,缺乏正确描述这种宽级配堆石料状态的相关剪胀理论与本构模型;2)堰塞体形成后,会受上游堰塞湖水位抬升、持续非稳定渗流、湖区滑坡涌浪、后期地震等外荷载作用的影响,缺乏稳定性评判的标准和方法;3)堰塞体缺乏必要的洪水溢流设施,容易发生溃决,且溃决水流冲蚀过程呈明显的非线性特点,溃口水力要素指标呈强非恒定流特征,缺乏反映宽级配堰塞体材料冲蚀机理的溃决过程数学模型。为此,有必要采取现场勘查、多尺度物理模型试验、数值仿真等综合手段开展研究,揭示堰塞体外观形态、内部结构和材料宏观力学特性及其时空变异规律,提出状态相关(级配、孔隙比、应力水平)的宽级配堰塞体材料剪胀方程,建立能适应复杂应力路径的广义弹塑性本构模型与坝体极限平衡分析方法;开展大型水工模型试验和溃坝离心模型试验研究,揭示非恒定流作用下堰塞体材料的动态冲蚀特性与堰塞体溃口演化规律,建立非恒定流作用时溃口动边界条件下的挟砂水流冲蚀方程,提出考虑流固耦合的堰塞体溃决过程数学模型,实现堰塞体漫顶或渗透破坏溃坝全过程水流运动特征、坝料输移规律、溃口演化过程及结构失稳的数值模拟;综合可靠度理论与溃坝过程数值模拟方法,提出能考虑流固耦合的堰塞体渗流、变形、稳定和溃决过程的一体化数值仿真平台,构建堰塞体全生命周期安全评价与灾变模拟理论体系与方法,为提升中国堰塞体防灾减灾决策水平提供科学的理论与技术支撑。
Abstract:Landslide dams are usually formed instantaneously by natural forces, the accumulation bodies have the characteristics of complex space structure, wide gradation of dam materials, poor dam stability, and they are easy to fail under the flow erosion. As a major natural disaster of flood and drought, safety evaluation and disaster prediction of landslide dams have been the focus of attention by the scholars around the world, but many questions remain unanswered, which are mainly manifested in: 1) Accumulation bodies are composed of natural wide-graded rockfill materials with significant state-dependent correlation, there is a lack of the state-dependent dilatancy theory and constitutive model of wide-graded rockfill materials. 2) After the formation of landslide dams, they would be affected by external loads, such as the rise of upstream water level of dammed lake, continuous unsteady seepage, landslide surge in the dammed lake, and earthquake, there is also a lack of standards and methods for stability evaluation. 3) Due to the lack of necessary flood relief facilities, the landslide dams are prone to fail; under the action of outburst flow, obvious nonlinear characteristics are manifested during the breach development, as well as strong unsteady flow characteristics of the hydraulic elements; there is a lack of numerical models for landslide dam breaching which can reflect the erosion mechanisms of wide graded materials. Therefore, it is necessary to conduct integrated scientific measures, such as field explorations, multi-scale physical model tests, and numerical simulation methods, so as to reveal the physical description, internal structure, macroscopic mechanical properties of the landslide dams and their spatial and temporal variations; and then, a state-dependent (i.e., gradation, pore ratio, and stress level) dilatancy equation for wide-graded landslide deposit will be presented, and a generalized elastic-plastic constitutive model that can adapt to complex stress paths and the limit equilibrium analysis method of landslide dam body will be established. Large-scale hydraulic model tests and centrifugal model tests of dam breaching will be conducted to reveal the dynamic erosion characteristics of landslide dam materials and the evolution law of breaches under the action of unsteady flow. Subsequently, the erosion equation of sand-laden flow under the dynamic boundary condition by the action of unsteady flow will be established, and the numerical model for dam breach process considering the fluid-solid interaction will be put forward to realize the numerical simulation of the characteristics of water flow movement, the law of dam material transport, the evolution process of breaches, and the structural instability of landslide dam in the whole process of overtopping and seepage failure. Integrating the reliability theory and numerical simulation method of dam breach process, an integrated numerical simulation platform for seepage, deformation, stability, and failure process of landslide dams considering fluid-solid will be developed; consequently, the theoretical system and method of safety evaluation and disaster prediction of the full-life cycle of the landslide dams will be established. The expected results achieved in the project will provide scientific theory and key technological support for improving the decision-making level of disaster prevention and reduction of landslide dams in China.
文章编号:202100611     中图分类号:    文献标志码:
基金项目:长江水科学研究联合基金重点支持项目(U2040221)
作者简介:第一作者:蔡正银(1965-),男,正高级工程师,博士.研究方向:土的基本性质与土工测试;土的本构理论;土工离心模拟技术.E-mail:zycai@nhri.cn蔡正银,江苏海安人,土力学及岩土工程专家,2001年于香港科技大学获得岩土工程博士学位,二级教授,博士生导师。现任南京水利科学研究院副总工,兼任中国水利学会、中国土木工程学会理事,《岩土工程学报》主编,中国水利学会岩土力学专委会主任,中国土木工程学会土力学与岩土工程分会土工测试专委会主任,江苏省岩土力学与工程学会副理事长,水文水资源与水利工程国家重点实验室副主任。国家863计划“20万吨级深水板桩码头关键技术研究”项目负责人、重大交通工程科研项目“深水桶式基础防波堤关键技术研究”负责人、国家重点研发计划“高寒区长距离供水工程能力提升与安全保障技术”项目负责人。长期致力于水利、交通、能源行业重大岩土工程关键科学技术问题研究,建立了深水板桩结构土压力理论与静止土压力“南水模型”,解决了板桩结构土压力“遮帘效应”“筒仓效应”“卸荷效应”等一系列关键技术难题,将中国板桩码头建设水平从3.5万吨级提升至20万吨级的国际领先水平;提出超软地基桶式基础结构土压力理论,破解了“波浪–结构–地基”静动力相互作用科学问题,为中国长达4000 km深水软基海岸线上的堤防建设找到了全新的解决方案;创建了高寒区土体“湿干–冻融”循环作用下的强度衰减与结构损伤双重互馈破坏机制,突破了渠系水–热–力多场耦合数值仿真与大时空尺度物理模拟技术瓶颈,提出渠道抗冻设计理论与渠道冻害安全评价方法,整体提升了中国高寒区渠道供水能力与安全保障水平。研究成果获国家和省部级科技奖22项,其中,国家科技进步奖二等奖1项(排名第1),省部级特等奖5项、一等奖9项(7项排名第1);发表学术论文216篇,主编专著6部,参编6部;获国家发明专利36项、实用新型专利14项;主编国家标准2部、水利和交通行业标准2部、水利和港口工程团体标准4部。先后获得全国优秀科技工作者、全国水利系统先进工作者、中国航海学会首届科技贡献突出人物、江苏省“333人才工程”中青年领军人才、水利部“5151人才工程”部级人选等称号,享受国务院政府特殊津贴。
引用文本:
蔡正银,钟启明,何宁,夏云峰,朱俊高.堰塞体状态相关剪胀理论与坝体溃决演化规律研究构想[J].工程科学与技术,2021,53(6):21-32.
CAI Zhengyin,ZHONG Qiming,HE Ning,XIA Yunfeng,ZHU Jungao.Research Framework of the State-dependent Dilatancy Theory and Breach Evolution Law of Landslide Dam[J].Advanced Engineering Sciences,2021,53(6):21-32.