苏州河河口水闸渗流场数值分析

建立苏州河河口水闸工程的渗流分析模型,按正向挡水和反向挡潮两种工况进行苏州河河口水闸工程的渗流计算,对各工况下水闸底板的扬压力、区域各点的水头和水力坡降、水闸结构的总体渗流规律等进行分析研究。数值分析结果表明,各水闸的渗流是稳定的,闸底板渗流扬压力分布符合一般规律。     

闸基搅拌桩水泥土施工配合比试验研究

针对合浦西沙联围挡潮闸工程闸基的地质情况,通过一系列搅拌桩水泥土配合比室内试验,选定适合该工程闸基搅拌桩的水泥土施工配合比。     

嶂山闸扬压力异常原因分析

介绍了嶂山闸的工程概况和闸基扬压力资料分析情况。嶂山闸闸基扬压力很高，其一系列异常现象均具有深层渗流的特征。定量分析结合水文地质资料研究表明，除上游库水外，闸基下承压水层可能是另一主要来源。     

高港枢纽节制闸地基稳定复核计算及分析

高港枢纽节制闸设计流量440m~3/s,其主要作用是向苏北地区供水,通过泰东河、通榆河、卤汀河等送水骨干河道,将长江水源源不断地东引、北调至沿海垦区和各个灌区。为了更好地了解工程现状,对高港枢纽节制闸进行了工程地基稳定复核计算。本文详细介绍了计算方法,并对计算结果进行了分析。     

州河节制闸塑性混凝土防渗墙设计与施工

州河节制闸是某引水渠首枢纽工程重要的控制性工程,起挡水、泄洪的作用。该闸基处土层为砂性地层,渗透系数较大,为防止渗漏和闸基渗透稳定,在闸室段及两岸采用塑性混凝土防渗墙进行垂直防渗。文章介绍了塑性混凝土防渗墙工程布置、设计和施工成墙关键工序。     

某水电站泄洪冲砂闸基础渗流分析

某水电站拦河枢纽工程泄洪建筑物为三孔敞开式泄洪冲砂闸，为了观测闸室基础渗流情况，在闸基沿水流方向埋设了5支渗压计，工程蓄水后闸基各渗压计的观测值持续增大。为了验证闸基渗流对实际工程安全的影响，通过收集该工程地质及基础处理相关资料，利用国产有限元分析软件AutoBank对泄洪闸建立了二维渗流有限元计算模型，对水闸基础渗流进行了理论计算，并对闸基础渗压计自安装后的实际观测资料进行分析，得到闸基各监测点渗流相对于闸前水位的时间滞后效应、扬压力折减系数以及实测扬压力分布情况，综合相关计算成果对闸基做出了渗透稳定评价。分析成果对该工程今后的实际运行管理有一定的指导意义，对同类型工程设计具有一定的参考价值。     

基于ANSYS的孟家闸闸室稳定有限元分析

水闸工程甚至水利枢纽最重要的工程安全部分就是闸室稳定与否。本文以孟家闸为工程实例,利用大型有限元ANSYS对该闸闸室稳定进行分析。结果表明,该闸闸室底板、闸墩等部位结构强度均满足规范要求,说明本文采用的简化分析模型及边界条件基本合理可行,为今后工程模拟提供了一定思路。     

某双向挡水节制闸工程的方案设计分析

南运河捷地节制闸为双向挡水,且闸基坐落在粉土地基上,根据工程这一特点,结合实际情况,方案设计进行了优化比较,取得了较好的成果.     

水库闸门不同开度下过闸水流水力特性研究

为研究伯斯阿木水库工程导流兼深孔泄洪洞工作闸门过闸水流水力特性,考虑闸门开度与过闸流量因素,借助水工模型试验方法,分析了过闸水流的水位、流速以及压强特征。试验结果表明,开度会影响闸前上游水位的稳定性,而过闸流量只会影响水位值。过闸流量对过闸水体流速影响效应高于开度因素。开度增大,面板时均压强降低,而过闸流量对之影响相反。开度、过闸流量会改变面板零压强分布区,影响面板渗流安全。论文可为挡水闸门的运营调度以及过闸水流稳定分析提供参考。     

引温济潮工程运行以来受水河道水质变化过程分析

对引温济潮工程受水河道(潮白河向阳闸—苏庄闸)2008—2013年连续6年的水质及其变化过程进行了分析,结果表明:受水河道的水质受来水(引温济潮工程出水)水质影响较大;工程运行以来受水的河道溶解性总固体、总硬度、氯离子和总氮较为稳定,硫酸根离子浓度则在高低变化中呈显著的上升趋势,河道的叶绿素a浓度也呈逐步升高趋势;叶绿素a、生化需氧量和p H值均明显高于进水,说明这些水质指标在河道中易发生变化。     

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。     

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.     

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。