引调水工程渠堤运行安全监控多指标评判准则

为解决单个测点的定量数值安全监控指标难以实现渠堤工程整体安全监控问题,需要建立基于多源信息的渠堤工程安全定性评判准则.在将效应量测值异常现象归纳为数值大小异常、变化过程异常、变化趋势异常和变化规律异常等基本表现形式的基础上,汲取长距离引调水工程安全运行的工程经验和专家知识,基于不同测点测值异常表现上的关联性和空间分布上...     

调水工程监测效应量运行安全监控指标的分级方法

调水工程是关系国计民生的重大基础设施,也是水资源优化配置的生态环境工程。基于土体结构、岩体结构和混凝土结构的破坏机理,结合统计学的“3σ准则”,对调水工程安全监测效应量监控指标等级划分方法进行研究。将工程安全状态从正常向异常变异的临界点对应的效应量值定义为监控指标的“一般警戒值”,将工程安全状态从异常向险情变异的临界点对应的效应量值定义为监控指标的“严重警戒值”,为评判工程运行安全性提供了科学依据。     

引黄入冀补淀工程桥梁设计

引黄入冀补淀工程为远距离引调水工程,引水线路长,沿线桥梁多,因此桥梁设计不同于单个桥梁的设计。根据引黄沿线跨渠桥梁情况,对桥梁进行分类,制定设计原则,对不同类型桥梁进行分类设计,为远距离引调水工程的桥梁设计提供参考。     

辽宁省重点引调水工程运行调度探究

长距离引调水工程调度运行是非常复杂的,特别是实施联合调度的调水工程,运行的安全和效率是整个引调水工程运行的重中之重,对引调水工程效益的发挥起着决定影响。为保障输水线路安全运行,全面实现工程的运行目标,需要根据引调水工程的建设特点和运行条件,研究科学的调度制度,形成高效低风险的调度系统。文章主要介绍了辽宁省某一引调水工程的特点及运行条件,以及现有引调水运行调度控制的方法和理论,提出了调度人员的职责、要求,构思了联合调度的自动化运行调度系统框架,同时也对联合调度的实现和意义进行了探讨。     

长距离引调水工程安全年度报告制度探索与实践

长距离引调水工程是优化水资源配置格局的重大战略性基础设施,具有线路长、建筑物多、环境和地质复杂等特点,其长期安全运行受到高度关注。开展工程安全年度报告工作是及时、动态掌握工程性态的有效手段。针对长距离引调水工程特点,探讨年度报告已有基础和编制原则,探索工程安全检查、安全检测和安全评估等年度报告主要工作的组织与实施,提出年度报告制度;基于南水北调中线干线工程首次年度报告工作的实践,简要介绍年度报告中安全检查、安全检测、安全监测等重点内容,及调度运行、维修养护、安全生产与应急管理等运行管理方面主要成效和存在问题;最后总结年度报告编制的经验认识和难点。年度报告制度在中线干线工程的成功应用可为类似长距离引调水工程安全管理提供借鉴。     

胶东调水调度运行安全监管体系研究

水利工程安全隐患主要来源于人的不安全行为、设备的不安全状态、环境上的原因和管理上的疏忽,通过构建胶东调水工程调度运行安全监控系统、创新工程运行安全智能监控技术和编制调水工程调度运行安全规范标准,探索水利工程调度运行安全监管体系建设.     

南水北调中线天津干线工程廊坊市段安全监测技术管理与应用

在长距离引调水工程中,由于输水线路长,建筑物数量、种类多,使安全监测技术在监控建筑物安全、掌握运行规律、验证设计、指导施工和运行管理等方面发挥着重要的作用。通过施工期和运行期积累的观测资料,可以了解建筑物各种物理量的变化范围和规律,当出现观测值异常或不利的发展趋势时,能够及时作出判断,采取有效措施。本文以南水北调中线一期天津干线工程为例,论述了工程安全监测管理,为未来水利工程运行管理提供了有益的借鉴。     

长距离引调水工程安全鉴定机制探讨

长距离引调水工程是优化水资源配置格局的重大战略性基础设施,具有线路长、建筑物多、环境和地质复杂、检修要求高等特点,其长期安全运行受到高度关注。针对长距离引调水工程的特点,基于南水北调中线干线工程安全鉴定办法编制和安全评估实践,简要分析了该类工程安全鉴定的难点,开展了安全鉴定机制的研究,提出了建立安全年度报告与单项、专项、专门和全面安全鉴定相结合的动态、全覆盖安全鉴定机制,解决了安全鉴定工作组织、基本程序与等级评定标准等问题,对长距离引调水工程运行期安全鉴定工作具有借鉴意义。     

引汉济渭受水区输配水工程分期实施方案剖析

陕西省引汉济渭调水工程是解决关中地区严重缺水的跨流域调水工程,受水区输配水工程在充分考虑规划受水点布局、输配水路线布置和不同水平年分期调水量等因素以及对引汉济渭工程总体进度的调度运行方式分析的基础上,得到了受水区输配水工程一期工程和二期工程按2025年和2030不同水平年规模的分期实施方案。更多还原     

乌江渡水电站大坝坝基扬压力安全监控指标的拟定

安全监控指标是对水工建筑物的荷载或效应量所规定的安全界限值。以贵州乌江渡水电站混凝土拱形重力坝坝基扬压力为研究对象,通过对2009年5月—2013年6月期间的坝基扬压力监测数据定性和定量分析,综合考虑坝基监测断面布置及各测点特征值分布情况选取了典型监控测点,建立了坝基扬压力统计模型,拟定了安全监控指标,对大坝日常运行维护提供了预警依据。     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.     

浙江省水域调查录入系统的设计和应用

浙江省水域调查录入系统将调查数据与电子地图相整合,对分类水域数据进行统计计算,并对输入数据进行合理性和完整性检查,得到调查范围内现有水域的详细数据,实现了水域调查数据输入、计算、统计和查询的数字化管理,提高了工作效率和工作质量,为各地下阶段水域保护规划编制和水域管理工作提供了数据支持。对该系统的设计原则、功能和技术设计等作了介绍。     

基于CT-连续加荷水泥乳化沥青混凝土细观损伤规律研究

利用CT技术对水泥乳化沥青混凝土的细观损伤过程进行实时扫描观测,获得了混凝土试件在连续加荷下的CT图像。通过采用直观分析法、CT数分析法、CT数与损伤变量关系3种方法分析表明,水泥乳化沥青混凝土的破坏过程可分为压密、扩容、裂纹扩展、破坏4个阶段,同时混凝土在受压过程中具有韧性,在极限荷载之前各断面处于压密和微扩容的强化阶段,极限荷载之后混凝土从损伤到破坏发展比较平稳。     

Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

The flood pulse advantage and the restoration of river-floodplain systems

The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed.     

浅谈天湖水电站水轮机运行故障及处理措施

简述天湖水电站投运以来各种故障的表现形式，分析其原因，提出了相应的处理方法及措施，并对合理利用国内外设备提出建议。