南水北调中线穿黄工程施工研究

南水北调中线穿黄工程是引汉总干渠中最在的跨河建筑物，该工程越黄河干流，工程规律大，施工难度高，工期长，是整个南水北调中线工程的关键工程，穿黄工程所处河段黄河宽度约７－９．５ｋｍ，为游荡性河道，河床覆盖层为粉细砂、细砂、中砂及粘土，厚度达４１－９４ｍ。工程设计输水流量５００ｍ＾３／ｓ，以输水渡槽及输水隧道两种主要型式及牛口峪，孤柏咀两条线路进行过多种方案的工程布置研究。本文重点介绍经比较推荐的孤柏咀     

南水北调中线穿黄工程布置方案比选

穿黄工程是南水北调中线引汉总干渠与黄河的交叉建筑物。是总干渠上规模最大、技术最复杂的建筑物、总干渠过黄河设计流理４４０ｍ＾３／ｓ，加大流量为５００ｍ＾３／ｓ，针对过河建筑物型式－－渡槽方案和隧道方案进行了不同过河线路的比较，并分别选择一条代表线路作过河建筑物型式的进一步比较，经分析比较认为，选择孤柏嘴双线盾构隧道方案是经济合理、技术可靠的最佳方案。最后对选定的中线隧道方案的布置研究作了进一步的阐述     

南水北调中线穿黄退水洞工程实现安全贯通

8月9日,南水北调中线的关键控制性工程之一——穿黄退水洞工程顺利实现贯通,为南水北调中线如期实现通水目标提供了保证。南水北调中线一期穿黄工程退水洞位于穿黄隧洞下游。通过退水洞穿越邙山将穿黄隧洞进口与黄河连通,主要作用是在穿黄隧洞检修期间,将总干渠多余水量排往黄河,同时兼有向黄河补水作用。     

南水北调中线穿黄工程:先进施工设备显身手

南水北调中线总干渠穿黄工程位于河南省郑州市以西约30km处．从孤柏嘴处穿过黄河。南岸起自河南省荥阳县王村．北岸终点为河南省焦作市温县南张羌乡．工程总长度达19．3km。该项工程主要任务是安全有效地将中线调水从黄河南岸输送到黄河北岸．在水量丰沛和需要时相机向黄河补水。穿黄工程由南、北岸渠道、南岸退水建筑物、进口建筑物、穿黄隧洞、出口建筑物、北岸新老蟒河交叉工程以及孤柏嘴控导工程等组成．工程总投资3137亿元。由于施工工期长、技术含量高、施工难度大．为确保穿黄工程按时、高质量完成．大量先进施工设备及先进技术被用于工程建设中。     

中线南水北调孤柏嘴穿黄河段河道整治

三门峡水库蓄清排浑运用以来，穿黄河段孤柏嘴山弯连年入流，穿黄渡槽修建后，对河势变化提出了更高要求，必须保证各种条件下黄河主流不发生大的变化。由于该河段位置特殊，加之游荡性河道河势变化复杂、穿黄河段整治基础薄弱，因此，为保证穿黄渡槽及北岸总干渠的安全运行，必须修建相配套的河道整治工程。本文根据穿黄渡槽和该河段河道整治两方面的要求，在现有工程的基础上对大玉兰至驾部河段进行了整治方案的分析研究，布设了张     

南水北调中线穿黄隧洞工程设计关键技术

正成果概况南水北调中线穿黄隧洞工程设计由长江勘测规划设计研究有限责任公司完成。穿黄工程是南水北调中线总干渠与黄河的交3叉建筑物,是总干渠上建设规模最大,技术最复杂的工程,也是控制工期的关键性工程,其设计流量为265m/s,加大流量为3320 m/s。穿黄工程采用2条盾构隧洞穿越黄河,单洞长4 250 m,隧洞内径为7.0 m。隧洞穿越黄河游荡性河段,该河段所处围土为饱和砂土地层,地质条件复杂,内水压达0.51 MPa,为国内首例采用盾构法施工的软土地层大型高压输水隧洞。技     

南水北调中线黄河北至漳河南渠段地形图测量

1概况南水北调中线工程总干渠自汉江丹江口水库引水,从陶岔渠首沿唐白河上游地区及淮、黄、海西部边缘兴建的向华北及京津调水的特大型输水工程。根据河南省水利勘测设计院“南水北调中线一期工程总干渠黄河北～漳河南渠段初设阶段补充测量任务及技术要求”,对黄河北～漳河南渠段进行1:1000带状地形图测量,渠线总长237．4km。1:1000带状地形图测量,平面坐标采用1954年北京坐标系1°分带,高程采用1985年国家高     

南水北调中线穿黄工程隆重开工

9月27日上午,备受世人关注的南水北调中线一期穿黄工程在黄河北岸的焦作温县隆重开工。国务院南水北调办公室副主任宁远、水利部副部长矫勇、河南省常务副省长王明义等在开工仪式上讲话。国务院南水北调办公室、水利部有关司局、黄委会、河南省政府有关厅局、郑州市和焦作市以及中线穿黄工程参建单位等参加了开工仪式。南水北调中线穿黄工程是南水北调中线工程的重要组成项目之一,是中线总干渠穿越黄河的关键性、控制性工程,也是南水北调工程在河南开工的第一个项目。穿黄工程的主要任务是安全有效地将中线调水从黄河南岸输送到黄河北岸,并…     

南水北调中线一期穿黄工程地质勘察

穿黄工程河段,黄河河势多变,地质条件复杂。穿黄工程地质勘察工作历时长达16 a之久。在从邙山头至汜水河口长达30 km的河段内,先后比较研究了邙山头线、桃花峪线、司马岗线、刘村线、孤柏嘴线、李村线和李寨线等7条线路,并对隧洞方案与渡槽方案进行了全方位的论证。以一期穿黄工程为背景,简述了穿黄工程的勘察工作经历和运用的多种勘察技术手段,及主要工程地质问题的研究方法和主要的工程地质工作经验。     

中线南水北调穿黄渡槽槽位选择

穿黄渡槽是中线南水北调工程中规模最大的跨河建筑物，技术难度高，涉及面广。除满足连续两岸输水总干渠的要求外，还应从黄河治理，河势及渡槽本身的技术经济指标等方面进行综合比较，而槽位选择则和以上诸方面密切相关。     

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。