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Probabilistic analysis for the response of nonlinear base isolation system under the ground excitation induced by high dam flood discharge

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Earthquake Engineering and Engineering Vibration 2017年第4期16卷 841-857页

作者： liang Chao Zhang Jinliang lian jijian Liu Fang Li Xinyao State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China School of Civil Engineering Tianjin UniversityTianjin 300072China Yellow River Engineering Consulting Co. Ltd.Zhengzhou 450004Henan ProvinceChina

According to theoretical analysis, a general characteristic of the ground vibration induced by high dam flood discharge is that the dominant frequency ranges over several narrow frequency bands, which is verified by observations from the Xiangjiaba Hydropower Station. Nonlinear base isolation is used to reduce the structure vibration under ground excitation and the advantage of the isolation application is that the low-frequency resonance problem does not need to be considered due to its excitation characteristics, which significantly facilitate the isolation design. In order to obtain the response probabilistic distribution of a nonlinear system, the state space split technique is modified. As only a few degrees of freedom are subjected to the random noise, the probabilistic distribution of the response without involving stochastic excitation is represented by the δ function. Then, the sampling property of the δ function is employed to reduce the dimension of the Fokker-Planck-Kolmogorov （FPK） equation and the low-dimensional FPK equation is solvable with existing methods. Numerical results indicate that the proposed approach is effective and accurate. Moreover, the response probabilistic distributions are more reasonable and scientific than the peak responses calculated by conventional time and frequency domain methods.

关键词： ground vibration high dam flood discharge structural response nonlinear base isolation system probabilisticanalysis

On the four-dimensional lattice spring model for geomechanics

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第4期10卷 661-668页

作者： Gao-Feng Zhao Xiaodong Hu Qin Li jijian lian Guowei Ma State Key Laboratory of Hydraulic Engineering Simulation and Safety School of Civil Engineering Tianjin University School of Civil Engineering Hebei University of Technology

Recently, a four-dimensional lattice spring model(4D-LSM) was developed to overcome the Poisson’s ratio limitation of the classical LSM by introducing the fourth-dimensional spatial interaction. In this work, some aspects of the 4D-LSM on solving problems in geomechanics are investigated, such as the ability to reproduce elastic properties of geomaterials, the capability of solving heterogeneous problems,the accuracy on modelling stress wave propagation, the ability to solve dynamic fracturing and the parallel computational efficiency. Our results indicate that the 4D-LSM is promising to deal with problems in geomechanics.

关键词： Lattice spring model (LSM) Fourth-dimensional spatial interaction Fracturing Geomechanics

Eff ect of Cementation on Calcium Carbonate Precipitation of Loose Sand Resulting from Microbial Treatment

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Transactions of Tianjin University 2017年第6期23卷 547-554页

作者： Yang Tang jijian lian Guobin Xu Yue Yan Hongyin Xu State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China School of Civil Engineering Tianjin University Tianjin 300072China

Microbe-induced calcite precipitation is a sustainable improvement technique for sandy soil, which can alter the properties of sand via microbial activity. In this study, we investigated the loose-sand-consolidation effect by controlling the injection velocity, bacterial and cementing-solution concentrations, and hold times. The results demonstrate that, as the cyclic batch increases, the utilization rate of the bacterial fluid increases and both the optical density (OD600) of the bacteria and urease activity decrease. Moreover, it was determined that a 3-h hold time for a 0.5 mol/L cementing solution with a cementing fluid velocity of 2 mL/min has the greatest bonding effect. The final strength of the loose sand with an increase in calcium carbonate content was further discussed. © 2017 Tianjin University and Springer-Verlag GmbH Germany

关键词： Bacteria Calcite Calcium Cementing (shafts) Microorganisms Precipitation (chemical) Sand Well cementing

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市场竞价下梯级水电站短期优化调度研究

水力发电学报 2007年第4期26卷 16-21,28页

作者：练继建马超天津大学建筑工程学院天津300072

针对梯级水电站短期优化调度的特点,通过对电力市场中发电厂商竞价策略特点的分析,提出了市场竞价下梯级水电站的竞价运行策略,构建了市场竞价下梯级水电站优化调度模型。模型采用概率分布来模拟发电厂商报价策略,并利用蒙特卡洛方法对... 详细信息

针对梯级水电站短期优化调度的特点,通过对电力市场中发电厂商竞价策略特点的分析,提出了市场竞价下梯级水电站的竞价运行策略,构建了市场竞价下梯级水电站优化调度模型。模型采用概率分布来模拟发电厂商报价策略,并利用蒙特卡洛方法对电力市场出清过程进行随机模拟,而且在最大效益子模型中考虑了梯级各电站发电成本不同的因素。最后通过实际算例,利用改进蚂蚁算法和遗传算法对硕多岗河梯级水电站在市场竞价条件下的整体调度过程进行了模拟优化求解,得出了较优的市场出清结果和梯级优化运行方案,并通过对优化结果的详细分析,指出了模型的优点和缺陷。

关键词：梯级水电站短期优化调度竞价运行策略改进蚂蚁算法蒙特卡洛

Multi-Objective Optimization of Water-Sedimentation-Power in Reservoir Based on Pareto-Optimal Solution

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Transactions of Tianjin University 2008年第4期14卷 282-288页

作者：李辉练继建 School of Civil Engineering Tianjin University

A multi-objective optimal operation model of water-sedimentation-power in reservoir is established with power-generation, sedimentation and water storage taken into account. Moreover, the inertia weight self-adjusting mechanism and Pareto-optimal archive are introduced into the particle swarm optimization and an improved multi-objective particle swarm optimization （IMOPSO） is proposed. The IMOPSO is employed to solve the optimal model and obtain the Pareto-optimal front. The multi-objective optimal operation of Wanjiazhai Reservoir during the spring breakup was investigated with three typical flood hydrographs. The results show that the former method is able to obtain the Pareto-optimal front with a uniform distribution property. Different regions （A, B, C） of the Pareto-optimal front correspond to the optimized schemes in terms of the objectives of sediment deposition, sediment deposition and power generation, and power generation, respectively. The level hydrographs and outflow hydrographs show the operation of the reservoir in details. Compared with the non-dominated sorting genetic algorithm-Ⅱ （NSGA-Ⅱ）, IMOPSO has close global optimization capability and is suitable for multi-objective optimization problems.

关键词： multi-objective optimization of water-sedimentation-power optimal operation of reservoir Pareto-optimal solution particle swarm optimization

水工弧形闸门流激振动特性物模-数模联合预测与安全分析

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水力发电学报 2007年第3期26卷 69-76页

作者：李火坤练继建天津大学建筑工程学院

水利工程中的弧形闸门对整个枢纽的安全至关重要,而水流诱发闸门振动现象很普遍,其动力安全关系到整个枢纽建筑物的安全,对闸门流激振动响应的合理预测是水利工程中的一项重要研究课题。基于嘉陵江新政工程弧形闸门实例,运用物理模型和... 详细信息

水利工程中的弧形闸门对整个枢纽的安全至关重要,而水流诱发闸门振动现象很普遍,其动力安全关系到整个枢纽建筑物的安全,对闸门流激振动响应的合理预测是水利工程中的一项重要研究课题。基于嘉陵江新政工程弧形闸门实例,运用物理模型和数学模型对该闸门流激振动特性进行了预测,综合考虑了整个闸门体系的耦合作用以及流固耦合效应,用物理模型仿真模拟了水力系统一闸门结构系统一支撑系统(闸墩)整体耦联振动,强调闸墩对闸门振动的影响,突破了以往将闸墩处理成刚性的方法。提出用三维板壳单元建立闸门空间数学模型并进行动力分析,最后联合物理模型和数学模型对其进行了动力安全分析,提出避免危害振动的措施。

关键词：水工结构弧形闸门物理模型闸墩振动响应有限元模型

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非经典阻尼的位移输入模型和多点反应谱注记

哈尔滨工业大学学报 2014年第6期46卷 79-85页

作者：柳国环练继建赵悦天津大学水利工程仿真与安全国家重点实验室天津大学建筑工程学院

为注记和揭示底部单元为非经典阻尼下位移输入模型与多点反应谱的准确性与稳定性,本文涉及理论推导与计算分析两个层面.讨论了在时域模型中底部单元分别为经典与非经典阻尼的区别,在时域模型的基础上推导给出底部单元为非经典阻尼时多... 详细信息

为注记和揭示底部单元为非经典阻尼下位移输入模型与多点反应谱的准确性与稳定性,本文涉及理论推导与计算分析两个层面.讨论了在时域模型中底部单元分别为经典与非经典阻尼的区别,在时域模型的基础上推导给出底部单元为非经典阻尼时多点反应谱公式,并通过算例验证.分析结果表明:底部单元为非经典阻尼时,位移输入模型不会出现底部单元刚度有关的阻尼项;理论上证明了在底部单元为非经典阻尼下位移输入模型和多点反应谱不存在结果不收敛问题;验证了底部单元为非经典阻尼下,采用位移输入模型计算结果的准确性和稳定性.

关键词：地震动时域模型位移输入模型多点反应谱非经典阻尼

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水库运行对下游河道横向连通性的影响

天津大学学报（自然科学与工程技术版） 2017年第12期50卷 1288-1295页

作者：练继建党莉马超天津大学水利工程仿真与安全国家重点实验室天津300350 天津大学建筑工程学院天津300350

水库建设及运行对坝下河流-洪泛区系统的生态格局产生显著影响.以海南省万泉河流域牛路岭水库下游加积至河口段为对象,基于河道平面二维水动力模型,开展水库调节对下游河流-洪泛区系统横向连通性的影响研究,重点关注淹没面积量级和频率... 详细信息

水库建设及运行对坝下河流-洪泛区系统的生态格局产生显著影响.以海南省万泉河流域牛路岭水库下游加积至河口段为对象,基于河道平面二维水动力模型,开展水库调节对下游河流-洪泛区系统横向连通性的影响研究,重点关注淹没面积量级和频率、长程相关等特性的变化.结果表明:水库调节使得下游大范围的天然水力过渡区转变为淹没区或干燥区,其尖峰厚尾分布特性削弱,极大地降低了洪泛区与主河槽的横向水力联系;淹没范围的长程相关性增加,淹没区与干燥区的交替周期延迟;不同水库调节情景对淹没情势的影响程度差异较大.

关键词：水库/大坝河流-洪泛区系统横向连通性长程相关性去趋势波动分析

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香溪河春季突发水华事件的应急调度策略

天津大学学报 2013年第4期46卷 291-297页

作者：练继建姚烨马超天津大学水利工程仿真与安全国家重点实验室天津300072

三峡水库蓄水后,春季香溪河中上游河段水华频发.通过调度方式改变香溪河回水区温差剪切分层流的运动特性,进而破坏藻类生长环境,能够有效抑制水华发生或降低水华暴发程度.基于此,结合实测资料建立了三峡库区-香溪河垂向二维富营养化模型... 详细信息

三峡水库蓄水后,春季香溪河中上游河段水华频发.通过调度方式改变香溪河回水区温差剪切分层流的运动特性,进而破坏藻类生长环境,能够有效抑制水华发生或降低水华暴发程度.基于此,结合实测资料建立了三峡库区-香溪河垂向二维富营养化模型,通过模拟详细探讨了调峰和蓄放水位对香溪河水华暴发过程的影响,并针对不同水平年分析了春季突发水华事件的应急调度空间.研究结果表明:当春季香溪河中上游河段有水华发生征兆时,可通过15,d左右的中期蓄水调度和日调峰运行有效降低藻类浓度,日均升水位超过0.1,m时,藻类浓度可下降11.5%以上.同时考虑入库径流过程、电站经济运行以及最大下泄能力等因素,较丰水年具有最大的调度空间.

关键词：香溪河突发水华事件富营养化应急调度调度空间