小浪底水库泥沙淤积特性及减淤运用方式探讨

小浪底水库在初期运行管理中采用了调控水位、异重流排沙、调水调沙、相机降低水位排沙、拦粗排细等综合调度运行方式,对减少水库和下游河道的泥沙淤积取得了显著效果。截至2016年汛前,水库累计淤积泥沙30.97亿m3,库区泥沙淤积形态及下游河道过流能力均发生了较大变化,为进一步提高淤积库容的利用率、尽量延长淤积库容的使用年限,对水库泥沙重点监测内容、淤积形态调整、汛期限制水位、调水调沙清水用量等进行了探讨。     

三峡水库泥沙淤积及减淤措施探讨

受上游水库蓄水拦沙、水土保持工程实施、河道采砂及气候变化等因素的影响,三峡水库的入库水沙条件发生了明显变化,水库淤积量大幅度减少。根据实测资料,分析了蓄水以来三峡水库淤积特性,以及减淤措施的实施时机及效果。研究表明:在入库沙量大幅度减少的前提下,三峡水库淤积大为减轻;汛期实施沙峰调度能够增大排沙比,减少水库淤积量;消落期实施库尾减淤调度能够有效缓解库尾局部河段淤积;局部河段清淤能够高效清除淤积泥沙,确保航道畅通。研究结果丰富了水库泥沙淤积管理方法和水库泥沙调度理论,为水库长期保持有效库容提供了参考。     

上游来水来沙变化及对重庆河段泥沙淤积的影响

三峡水库按175 m方案正常蓄水运行后,处于回水变动区的重庆河段将具有水库和天然河道的双重特性,随着水库运行时间的增长,该河段将呈现累积性泥沙淤积趋势.根据长江寸滩站和嘉陵江北碚站长系列水文观测资料分析,近年来三峡入库泥沙明显减少,而随着金沙江和嘉陵江上游梯级开发的逐步实施,上游大型水库拦沙效益将逐步显现,重庆河段的来沙量将进一步减少,可有效减缓重庆河段泥沙淤积速率,减少淤积总量和边滩淤积,增加三峡水库的兴利库容利用率,有利于重庆河段岸线及水资源综合利用.     

太平沟水库输沙量计算及对淤积的评价

太平沟水库输沙量计算及对淤积的评价安德罗波夫斯基水库的淤积强度取决于水库库容及河流的年泥沙径流量。由于河道型水库水量的流动性较之湖泊型水库大得多，这样只有部分入库泥沙在库内淤积，但另一方面，河道型水库的库容都小，所以，水库淤积得很快。位于黑龙江上的太...     

水库泥沙淤积分析计算及防治措施

水库淤积市一个普遍存在的问题,由于泥沙的淤积,使水库有效库容逐年减少,蓄水调节性能相应降低,对水库上游工程造成影响,同时威胁沿河两岸工农业生产的安全,还会引起河道冲刷下降,给水库的管理造成一定的困扰.因此,对水库进行泥沙淤积计算是十分必要的.根据水利水电工程设计规范,允许在受到资料限制时采用类比法和经验法对水库泥沙进行冲淤分析计算.以万两河枢纽工程泥沙分析计算为例说明.     

黄河三盛公水利枢纽入库泥沙处理的认识与分析

多年来三盛公水利枢纽工程库区泥沙淤积严重，使有效库容减少，直接影响到河道的行洪能力和调蓄能力。通过对水库入库泥沙基本特点及河床冲淤变化的分析，提出了现阶段应该采取的减沙措施和解决今后减少入库泥沙的对策。     

小型水电站泥沙淤积分析及防治措施

水库淤积，是一个普遍存在的问题。由于泥沙大量淤积，使水库有效库容逐年减少，蓄水调节性能相应降低；同时水库淤积引起回水上延，造成对水库上游工程的影响，同时威胁沿河两岸工农业生产安全；还会引起下游河道冲刷下降，造成水库管理工作困难等问题。在小型水力发电站设计规范中允许受到资料限制时可采用类比法和经验法对水库泥沙进行冲淤分析计算。在此以漾洱水电站工程水库的泥沙冲淤分析为例来说明，主要包括水库淤积形态分析、水库淤积计算、回水对上游影响分析、防止泥沙淤积的措施等。     

小型水电站库区淤积监测分析

通过对库区河道纵横剖面测量,建立水库泥沙淤积数据,研究电站运行期水库泥沙淤积与冲刷情况,准确计算水库库容量,进行库容损失分析,了解水库现状,进而评价水库运行质量,为电站管理提供决策依据。     

水库淤积的成因及对策

水库淤积,是一个普遍存在的问题。多沙河流存在,少沙河流也存在,由于泥沙大量淤积,使水库有效库容逐年减少,蓄水调节性能相应降低,直接影响灌溉效益;使原有的防洪库容减少,降低水库的防洪能力;同时水库淤积引起回水上延,造成水库上游地     

册田水库泥沙淤积研究

通过对册田水库泥沙淤积的研究,得出水库泥沙淤积的规律、水库发挥的作用以及人类活动对流域的侵蚀和入库泥沙的影响,为掌握水库的淤积特性和冲淤动态发展,有效控制水库泥沙淤积,延长水库使用寿命,提高水库效益,为水库调度运行、河道生态以及加固设计提供了科学依据。     

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。