宽尾墩一消力池的简化计算方法

本文对含有分流的水跃方程的特性进行了讨论，提出了宽尾墩一消力池等效分流比的概念，     

宽尾墩戽式消力池联合消能工的水力特性及其水力计算方法

本文系统地研究了宽尾墩戽式消力池联合消能工的水力特性,并和常规平尾墩型戽式消力池进行比较,试验表明,宽尾墩型戽式消力池极其有效地提高了平尾墩戽式消力池的消能效果。文中提出了宽尾墩型戽式消力池的水力计算方法,并阐明其消能机理,宽尾墩戽式消力池在岩滩工程中的研究和应用,说明宽尾墩戽式消力池是一种解决大单宽流量、低佛汝德数消能难题的有效而经济的新型水工建筑物。     

索风营水电站泄洪消能水力特性试验研究

为缩短工期，提高工效，索风营水电站采用宽尾墩 台阶坝面 消力池的联合泄洪消能形式。通过三种不同比尺的模型试验，分析比较了枢纽布置、表孔泄流能力、宽尾墩、台阶坝面及下游消能防冲等问题，提出了X形宽尾墩，它具有传统宽尾墩大单宽泄洪消能作用，同时又有台阶坝面小流量消能作用，使消力池底板承受冲击压强减小30％。     

宽尾墩T形墩消力池联合消能的计算方法

本文阐述了在T形墩消力池的基础上，通过系统的水力试验，对宽尾墩与T形墩消力池联合消能新技术进行的分析与研究。找出宽尾墩与T形墩消力池联合消能的内在联系，提出具体的计算方法，并用工程实践验证了研究成果的有效性。     

用于大单宽泄洪台阶坝面上的一种新型宽尾墩

近年来，宽尾墩＋台阶坝面＋消力池的联合消能工形式,在工程中不断得到发展与应用，但这些工程单宽泄量均不大于200m^3/s.m。在乌江索风营水电站水工模型试验的基础上，为台阶坝面的使用提出一种新型宽尾墩－X型宽尾墩，用以取代传统宽尾墩，这种宽尾墩与台阶坝面，消力池联合使用，既发挥了台阶坝面的消能作用，使宽尾墩＋台阶坝面＋消力池这种综合消能形式能够推广到大单宽泄洪建筑物上，同时也为台阶式坝面的发展直到一定的促进作用。     

宽尾墩跌坎消力池消能水力特性模拟研究

为探究宽尾墩跌坎消力池消能机理及其水力特性,采用RNGκ-ε湍流模型结合VOF两相流数值模拟方法,对宽尾墩联合平底消力池、无宽尾墩平底消力池和宽尾墩跌坎消力池三种方案进行了模拟研究,对比分析了这三种方案的流态及水面线、临底流速、压强分布。结果表明:宽尾墩跌坎消力池表现出掺气充分,水流紊动剧烈,临底流速小,压强小且分布均匀等特点。     

阿海水电站表孔X型宽尾墩消能技术初拟体型试验研究

根据已有工程经验,初拟了阿海工程表孔X型宽尾墩+台阶面+消力池的泄洪建筑物消能布置形式,通过水力学模型试验研究发现,宽尾墩对泄流能力影响很小,泄流量不但满足设计要求,而且还有小幅度的超泄能力。宽尾墩水舌分流合理,也能适应不同泄洪流量与消能要求。堰面及消力池底板压强分布基本满足工程结构要求。下游河道冲淤变化量很小,个别工况无任何冲淤现象发生。     

新型宽尾墩在索风营水电站的应用与研究

把宽尾墩应用到碾压混凝土台阶溢流坝面，形成“宽尾墩+台阶坝面+消力池”联合消能工，是我国科技工作者的一大创举。索风营水电站单宽流量达207m3/s·m，在应用台阶溢流坝面工程中属最大，经模型试验验证常规宽尾墩联合消能工已不能满足要求，于是提出了一种新型宽尾墩形式——X型宽尾墩，它继承了传统宽尾墩的优势，又拓宽了台阶坝面的消能作用。本文是“X型宽尾墩+台阶坝面+消力池”联合消能工在索风营水电站应用的水力特性研究成果的一部分。     

X、Y型宽尾墩水力特性研究

基于重力坝表孔泄洪的水工模型试验,研究了X型宽尾墩和Y型宽尾墩的泄洪流态、底表层流速、压力以及消能率。在不同泄流量以及闸门开度和下游水深的条件下,对不同体型宽尾墩的水力特性进行比较分析。试验结果表明：X型宽尾墩的最大临底流速比Y型宽尾墩小6.9%,X型宽尾墩的最大表层流速比Y型宽尾墩大8.12%,X型宽尾墩的消力池底板最大压力比Y型宽尾墩大43%,Y型宽尾墩的消能效果稍好于X型宽尾墩。     

宽尾墩在桃林口水库溢流坝上的应用

桃林口水库原设计为二级消力池形式的底流消能工，采用Y型宽尾墩后，减短了池长．提高了消能率，进而减轻了水流对下游河床的冲刷。本文结合桃林口水库枢纽工程的特点，对宽尾墩的体型参数进行了研究，同时对宽尾墩与消力池联合消能工的消能效果进行了分析和论述。     

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.