TCA2003全站仪及其在二滩大坝外部变形监测中的应用

TCA2003全站仪是近几年问世的测量机器人.利用它对大型工程建(构)筑物进行外部变形观测,具有精度高、工效高、所获取的数据准确可靠等优点.在二滩水电站外部变形监测中,采用同精度仪器与TCA2003全站仪,在相同条件下施测平面控制基准网和监测网,以实测的数据进行对比,验证了TCA2003全站仪用于变形监测的优越性,并指出了使用该仪器应注意的问题.     

TCA2003全站仪有其在二滩大坝外部变形监测中的应用

TCA2003全站仪是近几年问世的测量机器人。利用它对大型工程建（构）筑物进行外部变形观测，具有精度高、工效高、所获取的数据准确可靠等优点。在二滩水电站外部变形监测中，采用同精度仪器TCA2003全站仪，在相同条件下施测平面控制基准网和监测网，以实测的数据进行对比，验证了TCA2003全站仪用于变形监测的优越性，并指出了使用该仪器应注意的问题。     

基于测量机器人的远程遥控技术开发

为保证大坝在极端气象条件下的安全运行,需要无人值守的自动化变形监测系统,并使用无线网络连接数据中心和测量仪器。以Leica TCA2003测量机器人远程遥控技术为例,采用GPRS无线网络传送全站仪命令集数据,并通过无线互联网络实现对测量机器人的远程控制、测量和数据传输。利用GPRS无线网络远程控制测量机器人进行自动采集、传输变形监测数据可以保证监测数据的连续性、实时性和快速性,提高了工作效率,也提高了变形观测的自动化水平。     

测量机器人在闸坝变形监测中的实践

测量机器人系统在建筑物的变形监测中应用逐渐广泛,在确保满足具体工程监测精度要求的前提下,将该系统引入到水工建筑物变形的永久监测是一种有益的尝试。该文对某工程中采用LEICA TCA2003测量机器人系统监测闸坝变形的精度进行了分析,并介绍了其测量及数据无线传输的具体方法,可供其它类似工程参考。     

TCA2003自动化全站仪在乌鲁瓦提变形监测中的应用

TCA2003全站仪由于其操作简便，精度高，稳定性、可靠性强等特点而广泛应用于大地控制测量、高精度自动变形监测系统、安全监测领域等，本文主要介绍了TCA2003自动化全站仪在乌鲁瓦提大坝外部变形监测中的应用及数据后处理情况。     

昌吉市三屯河水库大坝外部变形监测及资料分析

介绍了基于TCA2003全站仪开发的变形监测控制网自动测量系统的功能特点,并对系统在昌吉市三屯河水库大坝变形监测中的应用情况进行分析。实际应用表明,系统测量效率高,精度高,大坝垂直位移变化、水平位移变化均符合重力坝变形的一般规律,大坝处在安全状况。     

TCA2003全站仪在小湾水电站高边坡监测中的应用

表面变形监测是水电站建设中安全监测的重要组成部分。运用TCA2003测量机器人和极坐标差分法进行变形监测,是近年发展起来的一种较为先进的技术手段。文章对TCA2003和极坐标差分法原理及其在小湾水电站的应用作了简要介绍。     

TCA2003测量机器人在白杨河水库自动化监测中的应用

外部变形监测是水利工程安全监测的重要组成部分。运用TCA2003测量机器人和极坐标差分法进行变形监测，是近年发展起来的一种较为先进的技术手段。文章对TCA2003和极坐标差分法原理及其在白杨河水库中的应用做了简要介绍。     

TCA2003测量机器人在白杨河水库自动化监测巾的应用

外部变形监测是水利工程安全监测的重要组成部分。运用TCA2003测量机器人和极坐标差分法进行变形监测，是近年发展起来的一种较为先进的技术手段。文章对TCA2003和极坐标差分法原理及其在白杨河水库中的应用做了简要介绍。     

徕卡TCA监测系统在岩滩大坝变形监测中的应用

徕卡多功能全站仪测量软件系统摒弃了传统断面仪外业测量时的繁琐配置和定位缺陷,减少了外业设备和作业人员编制数量,实现了变形测量野外数据采集软件控制、自动采集等功能,从而达到大坝变形网观测自动化、数字化、计算机化,保证了测量成果的准确性、高效率性,减轻了测量人员的劳动强度.文章介绍了徕卡TCA监测系统在岩滩大坝变形监测中的应用.     

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.