高寒地区深埋长隧洞施工方案比选研究

高寒地区深埋长隧洞地质条件复杂，高寒缺氧、断层构造和软岩变形是影响工程施工的突出性问题，钻爆法施工和TBM法施工各有优缺点，且均存在一定的难度。为此，对高寒地区深埋长隧洞施工方案需要进行综合比选，选择时应紧密结合隧洞勘探揭露的工程地质条件和拟定的工程线路方案，避免采用存在工程风险相对较大的施工方案。通过确定合理的施工方案，实现工程投资、施工工期及施工安全风险最佳效益组合。     

万家寨引黄工程南干线7~#隧洞TBM施工工程地质条件分析

根据万家寨引黄工程南干线7#隧洞全断面双护盾掘进机(以下简称TBM)的施工实践,就工程地质条件对TBM隧洞施工的影响和TBM的实际操作经验对工程地质条件的准确判定,作一些初浅的分析,以供类似工程参考。     

水工隧洞TBM施工适宜性围岩分类研究

隧洞掘进机TBM已逐渐成为水工深埋长隧洞的常规施工方法,而现行规范的围岩分类主要以隧洞围岩稳定性和支护措施为判别因素,仅适用于钻爆法隧洞。为此,梳理国内外不同工程的围岩分类指标体系和TBM施工特点,在隧洞围岩基本分类的基础上,重点分析了TBM掘进效率和不良地质条件,构建了TBM施工适宜性围岩分类方法。总结大量工程案例,综合权衡超硬岩、岩爆、断层破碎带、大变形、突涌水(涌泥)和高外水压力六个关键因素对TBM施工的定量影响,提出了可量化围岩分类指标。工程应用表明,TBM施工适宜性围岩分类方法可依据工程地质资料快捷完成围岩分类,能有效指导TBM隧洞施工,且具有较好的通用性和易用性。     

厄瓜多尔CCS项目双护盾TBM不良地质段施工

双护盾TBM在应用过程中,经常会因多种不良地质条件所约束。阐述了双护盾隧洞掘进机在不良地质条件下施工所遇到的典型问题,并以厄瓜多尔引水隧洞双护盾TBM施工为例,对涌水、断层破碎带、塌方等影响双护盾TBM的不良地质条件进行了分析研究,从宏观和微观的角度出发,提出了TBM通过不良地质洞段的方案和措施,可为今后双护盾硬岩掘进机施工提供借鉴。     

敞开式TBM穿越高浓度瓦斯煤层破碎带施工技术探析

通过对新疆某输水工程隧洞TBM施工过程中,穿越高浓度瓦斯煤层断层破碎带施工方案的研究、总结,首次提出瓦斯气体超前探测、瓦斯气体排放处理、多方式组合的加强初期支护,以及施工过程防爆管控等TBM穿越高浓度瓦斯气体煤层断裂破碎带的施工关键技术.鉴于国内采用TBM施工的隧洞工程没有遇到过此种极端不利的地质情况,因而文中总结的施工技术方法和施工经验,对今后类似地质条件的TBM施工具有一定的借鉴意义.     

单护盾TBM在不良地质隧洞施工中的问题及解决措施

根据引洮供水一期工程7#隧洞不良地质条件下单护盾TBM隧洞施工时遇到的一系列问题,对TBM掘进机进行了优化改进,并提出了该工程不同不良地质条件下TBM掘进时所遇到的问题及解决措施,从而提高了TBM的施工进度,保证了施工过程中人机的安全,可为单护盾TBM隧洞施工提供借鉴经验。     

关于隧洞TBM施工地质条件适宜性的探讨

随着隧洞工程向"深、长"方向发展,TBM施工技术应用越来越广泛。结合近年来隧洞TBM施工技术的研究成果,对影响TBM施工适宜性的岩体地质环境和岩体性状条件进行分析研究,编制了"隧洞TBM施工适宜性判定"标准,作为SL 629—2014《引调水线路工程地质勘察规范》"附录C"的内容。并对TBM施工地质工作提出设想和建议。     

TBM穿越超长距离断层破碎带施工技术研究

针对广西桂中治旱乐滩水库引水灌区一期工程北干1标段16.07 km隧洞TBM掘进过程中突遇超长距离断层破碎带的恶劣地质条件,结合以往的TBM施工经验,通过对TBM设备改良和对TBM施工技术研究改进,采取了超前水平钻探取芯、Mcnally系统支护、侧墙防坍塌临时支护、隧洞仰拱软基换填、侧墙大撑靴加压、长距离隧洞皮带洞内冷粘、断层破碎带拱架更换等多种关键施工技术以及固结灌浆等其他施工技术相结合的方式,保证TBM设备安全、快速地通过了该段超长距离断层破碎带,提升了TBM在相似地层中的施工能力。     

鄂北水资源配置工程宝林隧洞TBM施工方法初探

宝林隧洞是鄂北地区水资源配置工期最长的节点性工程之一,为最大限度减少工程建设对生态环境的影响,采用TBM施工。文章根据宝林隧洞的地质和施工条件,对开敞式TBM和双护盾式TBM进行了比较,发现宝林隧洞适合采用开敞式TBM施工;结合开敞式TBM的施工工艺,初步探讨了宝林隧洞开敞式TBM施工方法。     

尼泊尔某引水隧洞工程TBM选型初探

结合尼泊尔某引水隧洞工程,初步探讨了全断面岩石掘进机(TBM)的施工适宜性及不同类型TBM的适用范围,根据该引水隧洞工程地质条件分析,判断隧洞总体上适宜采用TBM施工,并从工程地质角度建议选择双护盾TBM。     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

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。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

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。     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

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.     

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.