三峡永久船闸输水廊道工作阀门设计研究

针对三峡永久船闸级数多、工作水头大、水力学条件复杂等特点，在船闸输水廊道工作阀门的布置和选型上，作了大量的模型试验和比选研究。从已建工程积累的实践经验和布置方案的优化成果考虑，确定输水工作阀门采用反向弧形门型式。根据孔口尺寸和工作水头条件，采取首末闸首与中间闸首不同的规格，门体结构和布置型式为横梁全包式，并以各部位包护板形成闭合框架的型式。在门楣上设置一排通气孔，同时在底坎上亦采用了强迫通气设施。比选确定了支铰型式及其自润滑方式     

三峡永久船闸输水反向弧形阀门流激振动问题研究

本文采用原型观测、模拟试验和理论分析等手段,对三峡永久船闸高水头输水反向弧形阀门的流激振动问题进行深入研究。研究内容包括:(1)以五强溪船闸反向弧形阀的原型观测为基础,对三峡船闸反向弧形阀及输水廊道紊流场进行精细的数值模拟和试验研究,通过综合分析,对三峡反向弧形阀门可能出现的小开度强振区的振源进行预报。(2)研究符合金属结构水弹性相似的高容重、低弹模的特殊材料系列,并用该材料制成了1∶20三峡反向弧形阀的"完全水弹性相似"的流激振动模型;用该模型进行了实验(干)模态分析,并与有限元的理论模态分析相比较,二者符合较好,说明它的动力性能良好,可用于反向弧形阀门的各项水弹性振动问题研究;在大型减压箱中对三峡永久船闸反向弧形阀在输水过程中的紊流流激振动进行模拟,预报阀门结构的动力特性及动力响应。最后对减振、抗振措施提出相应建议。     

三峡永久船闸输水系统设计

三峡永名船闸为双线连续五级梯船闸，设计总水头１１３ｍ。按只补不溢的原则划分水级，中间级船闸最大工作水头为４５．２ｍ，每级闸室的输水时间为１２～１３ｍｉｎ，着重对船闸的水级划分，输水系统的布置，闸室停泊条件，阀门段空化，补溢水方式和超灌超泄等问题的研究进行了论述。     

三艘船闸设计中的关键技术问题是如何解决的(下)——船闸技术的新发展

问题8三峡船闸输水系统反向弧形阀门是如何解决高水头频繁操作的启闭问题的? ——谈高水头大型反向弧形阀门及其启闭机技术 三峡船闸输水系统反向弧形阀门的最大工作水头45.2m,支铰单侧最大拉力990t,启门力1500 kN,闸顶竖缸液压启闭机吊杆的最大长度约70m。阀门需能频繁快速开启,对     

三峡工程永久船闸水力学研究

三峡工程永久船闸总水头为１１３ｍ，为双线连续五级，中间级最大水头达４５．２ｍ，超过了国内外已建大型船闸的水平，其水力学问题十分复杂，通过多年来大量的试验研究，选用双侧主廊道四区段领先八支管动力平衡输水系统，输水阀门向弧形门，门后廊氏部吾突扩体型，门楣处减蚀措施，采用快速开启阀门和提前关闭阀门，以消除闸室水面惯性超高的不利影响，进水口旁侧取水方式等，不仅满足各项设计要求，并能保证船闸的安全运行。     

三峡船闸输水系统反弧门启闭力特性研究

 三峡船闸输水系统阀门设计拟采用双面板式反向弧形门。通过比尺为17的物理模型，对阀门启闭力进行了试验观测， 并分析了启闭力的时均变化过程、启闭力脉动及其频域特性。从减小阀门动水启门力的角度， 对反弧门几何体形进行了优化。     

三峡船闸输水阀门及其启闭机研究和设计

三峡船闸输水阀门工作水头达到45.2 m,根据大量的试验研究的成果,对输水阀门及其启闭机的型式选择、布置和防空化等技术问题,提出了设计方案.     

船闸水力学研究的新成就

本文主要介绍近１０年来我院在船闸水力学研究方面的新成就。包括船闸输水系统布置、闸阀门水力学和引航道水力学等。并结合葛洲坝、三峡、五强溪等大型通航水利枢纽工程，重点介绍在船闸输水水力计算、闸阀门非恒定流水力学、输水阀门段廊道体型以及门楣通气减蚀措施等方面的研究成果。     

船闸水力学研究的新成就

本文主要介绍近１０年来我院在船闸水力学研究方面的新成就，包括船闸输水系统布置、闸阀门水力学和引航道水力学等。并结合葛洲坝、三峡、五强溪等大型通过航水利枢纽工程，重点介绍在船闸输水水力计算、闸阀门非恒定流水力学、输水阀门段廓道体型以及门楣通气减蚀措施等方面的研究成果。     

泰州引江河高港二线船闸输水系统布置及水力计算分析

结合高港二线船闸工程具体条件,按照《船闸输水系统设计规范》的要求,研究确定了船闸短廊道和三角门门缝联合输水的输水系统型式及具体布置方案,计算分析了充泄水阀门开启方式,通过建立船闸联合输水数学模型计算了闸室输水水力特性.结果表明,确定的船闸输水系统布置及阀门开启方式是合适的,相关水力指标满足规范及设计要求;设计的消能工布置适合高港二线船闸工程特点,可获得较好的闸室水流条件;同时根据水力特性计算结果提出了阀门启闭系统设计建议.     

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。     

Serial discontinuities in a Rocky mountain river. I. Distribution and abundance of plecoptera

Samples were taken year-round at eleven sites along the altitudinal profile (2900-1400 m a.s.l.) of the Gunnison River, a 329 km tributary of the Colorado River, to document the distribution of the Plecoptera and to evaluate responses to hypolimnial-release dams in the headwaters and middle reaches. Twenty-two species were present, with the greatest species richness occurring in an unregulated segment upstream of the middle reach dams; average nymphal biomass over the study period (175 organisms, 395 mg dry mass m^?2) was also greatest in this segment. Only four species (58 organisms, 48 mg m^?2) were present in the tailwaters of the headwater dam and values were greatly reduced (nine species; 35 organisms, 180 mg m^?2) below the middle reach dams. The stonefly community recovered ca. 80 km downstream from the last dam (15 species; 244 organisms, 250 mg m^?2), apparently in response to natural resetting of environmental conditions corresponding to those above the middle reach dams. At the most downstream site (11) only four species (four organisms, 16 mg m^?2) were present. The observed distributional pattern is a classic serial discontinuity in response to hypolimnial stream regulation in a temperate latitude river.     

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.