三峡升船机船厢驱动系统安装方法与质量控制

三峡升船机船厢驱动系统是船厢升降运行的关键机械设备,驱动系统结构复杂,系统安装精度要求高,需要在船厢结构加载条件下进行精确定位、安装,并要能适应在极端事故工况条件下船厢结构变形。对驱动系统安装方法及质量控制要点进行了总结,包括小齿轮托架总成、主减速箱、同步轴系统等。相关经验可为类似大型机械安装提供借鉴。     

亭子口水利枢纽航运工程升船机船厢运输组装

升船机船厢布置在船厢室内,其整体尺寸大,安装单件体积大,重量重,受安装场上下游及空间环境条件限制,船厢安装就位是升船机工程安装的难点。亭子口水利枢纽航运工程船厢运输组装方案结合亭子口升船机船厢布置特点,解决了船厢就位难的问题,该方案的顺利实施,为升船机船厢安装提供了又一切实可行的方法。     

思林升船机平衡重挂装技术及控制方法研究

在分析思林升船机平衡重类型及分布位置的基础上,确定了分类型、分批次、对角线挂装的平衡重挂装方案。具体控制方法为:优先挂装安全和转矩平衡重,利用安全制动器保障挂装安全;为保证平衡重与船厢重量平衡,分批次挂装及船厢充水;为控制船厢扰度,每次按近均布原则选点挂装,保证船厢主纵梁受力均匀;为防止船厢倾斜,采用两侧对角线挂装,保证船厢水平控制。平衡重挂装和船厢充水同步进行,船厢重量由胎架平稳过渡到钢丝绳上,建立了升船机的平衡初态。最后通过船厢重量调平,保证了船厢与平衡重的重量为3 300 t,船厢水位为2.5 m;船厢水平调平,让四吊点的水位差控制在20 mm内,保证船厢上钢丝绳均衡承载,达到升船机的平衡稳态。相关经验可供类似升船机平衡重挂装借鉴。     

大型升船机船厢出入水受力特性原型观测

船厢出入水过程中复杂的流固耦合作用是下水式升船机关键技术问题。针对目前世界上最大的船厢下水式升船机——景洪水力式升船机船厢出入水过程中的力学问题,首次通过系统的原型观测,研究揭示船厢出入水过程中厢体的受力变形特性、船厢的倾斜量及同步轴扭矩的变化规律、船厢的振动响应与噪声及附加水动力荷载特性,并探讨了船厢出入水运行速度的影响。观测结果表明,船厢入水过程中由于船厢侧荷载发生显著变化,船厢发生最大弯曲变形约2.7 cm,船厢纵倾增大不足20 mm,最大扭矩变化162 kN·m,船厢振动、噪声、吸附力均不大;不同速度出入水,各项参数变化规律一致,但随速度增大,各参数呈增大趋势;船厢出水后能够完全恢复到入水前状态,出入水过程稳定收敛,船厢出水启动瞬间和船厢底铺板脱离水面时刻是出入水过程的关键节点,各项参数变化迅速。观测结果不仅为景洪升船机安全运行提供依据,也为其他下水式升船机设计提供参考。     

高坝通航技术在水口工程的新发展

水口水电站坝高101m,航运过坝采用一线三级船闸和一线垂直升船机。水口升船机是当时国内已建和在建同类升船机中总体规模最大的升船机,也是我国第一座自行设计、制造、施工和安装的大型升船机。在塔楼结构动力分析和试验研究、塔楼滑框倒模施工、升船机整体模型试验研究、承船厢整体制造和浮运、船厢安全锁定装置和船厢对接密封装置试验研究、整机安装及联调试验等方面充分体现了水口升船机的建成是高坝通航技术的新发展。     

岩滩升船机总体技术居国际先进水平

岩滩升船机经过专家们考察、调研认为 :该升船机在设计和制造中采用一系列新技术、新工艺 ,成功地解决了卷扬提升垂直升船机的主要技术问题。卷扬提升、部分平衡、船厢下水式垂直升船机 ,在国内外都是第一座 ,升船机的总体技术水平居国际先进水平 ,专家们的技术评价结论是 :(1)采用卷扬提升、部分平衡、船厢下水式升船机 ,成功地适应了岩滩水电站提升高度较大 ,下游水位变幅大、变率快等特点。 (2 )保证制造精度和安装选配 ,确保提升系统在 6 8 5ｍ全行程升降过程中 ,保持承船厢位置水平 ,其四角水偏差值不超过5ｍｍ(设计要求不大于 2 0ｍｍ…     

三峡升船机关键技术问题

三峡升船机规模宏大,采用齿轮齿条爬升方式,运行条件复杂.通过对塔柱变形、土建结构和船厢室段一、二期埋件精度、齿条和船厢设备制造等关键技术问题的分析,提出对策,确保建成的升船机能安全可靠地投入运行.     

向家坝升船机平衡重系统钢丝绳无规律伸长研究

在向家坝升船机平衡重系统钢丝绳(预张拉钢丝绳)安装过程中,其无规律伸长对升船机运行产生了影响,即当船厢运行至上极限位置时,有可能造成平衡重块与平衡重井底板接触,从而导致船厢急剧下降的恶性事故发生。通过分析、试验,研究了平衡重钢丝绳无规律伸长的原因及对现场安装的影响,并提出相应的方案,有效地解决了平衡重块存在触底风险的问题。     

浅谈三峡升船机停位找点装置安装

三峡升船机承船厢在上(下)闸首与工作闸门对接,要求船厢水位与上(下)游航道水位准确平齐。停位找点装置安装在承船厢厢头两侧,以便船厢承船厢正确的减速、停位。简要介绍了三峡升船机停位找点装置的组成、工作原理以及安装调试技术要求。针对设备安装调试过程中出现的信号丢失问题进行了技术改造,进而提高了停位找点装置运行的稳定性。     

下水式钢丝绳卷扬垂直提升升船机水力特性研究综述

下水式升船机可适应较大的水位变幅及较快的水位变率.我国中西部地区河流具有水量及水位随季节变化大、河势狭窄等特点,因此下水式升船机有较广阔的应用前景.主要针对岩滩、构皮滩升船机的研究成果,首先总结了下水式钢丝绳卷扬垂直提升升船机的特点、运行方式、船厢出入水过程中所涉及到的水动力特性;其次,概述了船厢出入水过程中船厢内以及船池内水体的波动特性,以及前人所进行的理论分析及公式推导;最后,综述了船厢出入水时,前人关于船厢附加水动力荷载产生机理的探讨以及为降低附加水动力荷载而采取的工程措施及其效果,总结了相关的经验公式.此外,提出了下一阶段需要研究的重点问题,如船厢出入水过程升船机水动力特性规律性的研究;数值模拟计算研究;结合物理模型,深入探讨船厢受力、船厢运行平稳性以及提升系统荷载的变化特性等.     

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。     

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.     

浅谈天湖水电站水轮机运行故障及处理措施

简述天湖水电站投运以来各种故障的表现形式，分析其原因，提出了相应的处理方法及措施，并对合理利用国内外设备提出建议。