浅谈油车水库帷幕灌浆施工中的孔斜控制

针对宜兴市油车水库工程左岸防渗帷幕灌浆施工中遇到的岩溶地带,在溶蚀裂隙及泥沙充填地层钻孔孔斜控制困难,从地质地层、人、钻进施工技术参数及钻孔机具等方面,分析了造成孔斜过大的原因,提出了在实际施工中付诸实施的更为有效的孔斜控制及预防措施及管理方法,保证了钻孔的施工质量。     

浅探深孔帷幕灌浆孔斜成因与处理

在深孔帷幕灌浆钻孔施工中，孔斜控制具有重要意义，着重探讨孔斜成因及其不良影响，介绍了孔斜的预防和处理措施，对保证钻孔方向的重要性提出了商榷性的建议。     

跨孔对测孔斜校正矢量方法研究总结

跨孔对测法也叫穿透测试法，被广泛地应用于岩土工程波动勘测中。由于对测的双孔不平行会导致激振点与接收点间的穿透距离与孔口距离不一致，因此穿透距离应进行孔斜校正。当钻孔越深、孔口距离越近，这种由钻孔倾斜引起的穿透距离变化就越大，孔斜校正就越显得重要。本文在对现有孔斜校正方法总结与研究的基础上，提出钻孔倾斜校正矢量法，该法能对不同情况下的孔斜进行校正，弥补了现有各种校正方法的不足。     

孔斜对帷幕灌浆质量的影响

在帷幕灌浆施工中,孔斜控制具有重要意义。文章重点探讨孔斜成因及其对灌浆质量的影响,研究在钻孔施工中孔斜的控制和处理措施。     

深孔帷幕灌浆孔斜成因与处理

在深孔帷幕灌浆钻孔施工中,孔斜控制具有重要意义。着重探讨孔斜的成因及其不良影响,介绍了孔斜的预防和处理措施,对保证钻孔方向的重要性提出了商榷性的建议。     

深孔帷幕灌浆施工技术

熟练掌握深孔帷幕灌浆的工艺流程，对深孔帷幕灌浆具有重要的意义。深孔帷幕灌浆钻孔施工中，如何控制孔斜具有重要意义。研究成孔偏斜及其不良影响的控制方法，及其偏斜的防范和处理措施，对钻孔方向的重要性提出了合理化建议。     

万安水利枢纽变形监测设施设计施工若干问题探讨

在万安水利枢纽变形监测设计及实施中，发现变形监测部分设施尚存在一些具体问题需进一步完善，如倒垂线锚固点位置的确定，机钻孔有效孔径确定，孔斜测量及锚块的定位安装；深埋测温钢管标机钻孔孔斜要求；双金属标标芯管线膨胀系数的测定精度等。为此，在总结经验的基础上，进行了分析研究，从而得到了新的倒垂代机钻孔有效孔径确定的公式，孔斜测量及锚块定位安装的新方法，深埋测温钢管标机钻孔孔斜要求，双金属标标芯管线膨胀系     

倾斜导井反井掘进技术研究

在大倾角深斜孔反井钻井技术的研究中，通过对斜井中钻具的受力、钻进参数、钻孔偏斜原因以及钻机选型和改造等进行分析研究，成功地钻成十三陵抽水蓄能电站２号下斜压力管道导井，取得月成孔１３０ｍ、钻孔偏差率仅１．４２９％的好成绩。     

基于ＡＮＳＹＳ的深孔帷幕灌浆钻孔弯曲机理研究

大岗山水电站深孔帷幕灌浆工程量大,灌浆孔孔斜控制要求高,防斜技术难度大。钻孔弯曲机理研究对指导钻进成孔,防止钻进事故,加快帷幕灌浆施工速度有重要意义。从工区地质条件入手,对深孔帷幕钻孔弯曲原因、钻孔弯曲条件进行分析,并利用ＡＮＳＹＳ软件有针对性地建立了不同的钻孔弯曲分析数值模型,很好地揭示了钻孔弯曲机理。根据研究结果采取针对性措施,制定、调整、优化钻进工艺参数,很好地将钻孔偏斜控制在设计范围内,避免了发生钻进事故,加快了帷幕灌浆施工速度,产生了可观的经济效益。     

岩滩水电站倒垂线孔施工

介绍岩滩水电站大坝倒垂线观测系统的倒垂线孔钻孔的孔斜控制、孔斜测量、孔斜纠偏等施工技术及廊道内遇长岩芯的处理方法。     

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。     

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。     

Desiccation and recolonization of phytobenthos in a regulated desert river: Colorado River at Lees Ferry,Arizona, USA

We tested the recolonization of the phytobenthic community in the tailwaters of Glen Canyon Dam following long- and short-term experimentally induced desiccation. The response of Cladophora glomerata, Oscillatoria spp., miscellaneous phytobenthos species and periphyton was studied over 18 weeks using three treatments: (1) undisturbed control cobbles from the submerged zone; (2) cobbles desiccated and replaced into the submerged zone; and (3) cobbles desiccated and replaced into the varial zone. Periphyton density and compositional response resulting from these treatments were also examined. Desiccation treatments were significantly different in biomass from controls throughout the study. The biomass of desiccated and replaced river cobbles averaged <30% of the controls for C. glomerata and periphyton during the 18-week recolonization period. In contrast, the biomass of the control Oscillatoria and miscellaneous phytobenthos species averaged only 3 and 50% of that in the desiccation treatments, respectively. Cladophora, the dominant alga, comprised 77% of the phytobenthic biomass. A significant positive relationship between discharge, Cladophora and periphyton biomass was present in all treatments, while there was a negative relationship with discharge for Oscillatoria and miscellaneous phytobenthos species. There was a significant inverse correlation, as well as a pattern of separate biomass dominance, between C. glomerata and Oscillatoria. Cladophora was the dominant phytobenthos species on cobbles below the baseflow and Oscillatoria was dominant on cobbles in the varial zone. In general, the Cladophora biomass decreased under intermittent drying conditions, while Oscillatoria declined under permanently wet conditions. Diatom composition was not significantly different between treatments; however, their density was lower on desiccated cobbles. Diatom density on desiccated cobbles in the submerged and varial zones averaged 69 and 42% of that of the controls, respectively. Recovery and maintenance of benthic resources are hindered by fluctuating flow regimes driven by electricity and irrigation requirements. Repeated desiccation of the phytobenthos has major effects on the bottom-up interactions in the Colorado River ecosystem. © 1998 John Wiley & Sons, Ltd.