螺河桥闸重建工程地质条件分析

通过对螺河桥闸重建工程2^#、3^#闸址的地质资料收集分析、野外地质测绘、钻探及室内外试验,结合场地土层剪切波速测定等手段,初步查明两个闸址的工程地质条件,得出软弱层分布厚度特征、砂层渗透性以及对工程地震、液化及渗漏可能的影响。重点从地层组成及分布、闸基承载力、抗滑稳定、防渗处理等方面对两个闸址进行对比分析,认为2^#闸址工程地质条件优于3#闸址,初步推荐2^#闸址为重建闸址。     

大汶河砖舍拦河闸工程闸址方案比选

为保障肥城市大汶河砖舍拦河闸工程的重建工作,本文从地形、地质、占地、交通等条件对项目闸址建设方案进行比选,由此选出最优闸址方案,为类似拦河闸项目闸址选定工作提供参考。     

王引河芒山闸除险加固可行性研究

永城市王引河芒山节制闸始建于1959年,1975年进行扩建。自扩建以来已连续运行40多年,虽经多次维修,目前仍存在许多安全隐患。经河南省水利厅核查,该水闸安全级别为四类,按相关规定的要求应当拆除重建,但由于下游海漫段被现有省道桥梁占用,在原址重建已不具备条件。因此,文章对该闸目前存在的各类问题进行总结,并对该闸除险加固的必要性及移址重建的可行性进行分析,以期为该闸移址重建提供相应参考。     

吴刘节制闸改址重建对颍河防洪的影响

颍河是河南省重要骨干排水河道,吴刘节制闸为颍河中下游的一座重要控制性工程,目前水闸整体结构破损严重,结构型式也不能满足防洪的要求,水闸原址位于漯河和许昌两市交界处,存在水事纠纷隐患,不能满足水闸调度运用需要,需改址重建。文章从河道及城市防洪、淹没损失、水事纠纷及分洪机遇等四个方面对节制闸改址重建后对颍河的防洪影响进行了分析,分析得出吴刘节制闸的改址重建对颍河的防洪影响是有利的,从而为工程的建设实施提供参考依据。     

大厂县芦庄闸拆除重建工程设计洪水分析

廊坊市大厂县芦庄闸建成于1956年7月,已经运行53年,经鉴定,为四类闸,建议拆除重建。为合理确定新建芦庄闸规模,对其所在的鲍邱河闸址以上流域进行设计洪水分析。     

洪潮江水闸闸线选择及水工建筑物布置

洪潮江水闸由于年久失修,水毁严重,造成闸室上部结构垮塌,基础被淘空,下游河床形成多处冲坑,重建工程的方案通过对闸址地形地貌、地质、水文、枢纽建筑物布置、对外交通、征地拆迁、施工、工程投资等条件的分析论证,选择在原闸址上重建。确定的水闸枢纽布局,采用16孔×10 m露顶式平底闸方案。工程建成后运行效果良好。笔者对洪潮江水闸闸线选择及水工建筑物布置进行详细介绍。     

三刘拦河闸除险加固工程设计及结构计算

针对三刘拦河闸淤积严重、闸孔净宽偏小泄洪能力不足、闸墩混凝土碳化漏筋稳定性差、闸门止水损坏缺失漏水严重等,导致蓄水灌溉供水可靠性差、防洪排涝不畅、上游防洪压力增大等问题,结合水闸工程特性、运行现状和安全复核成果,对拦河闸闸址和闸型选择、构建物布置和结构稳定性进行了详细论证分析。结果表明,优选的原闸址拆除重建提升闸方案,在地形地质适应性、施工便捷性、工程投资经济性和运行管理灵活性等方面均较优。重建工程实施后,可有效改善拦河闸的挡蓄水、防洪排涝和节水灌溉等方面的功能。     

浅析阜宁腰闸拆除重建后的闸位确定

阜宁腰闸经安全鉴定后综合评定为四类工程,亟待通过拆除重建来消除工程隐患.合理确定拆建工程的闸位是除险工作的第一步,需要通过明确水闸工程的闸址位置和中心线来实现,而闸址位置和中心线可以通过工程周边因素分析和计算流体力学计算来较为科学地确立,从而保证工程效益的正常发挥.     

鸡西市鸡冠山渠首水毁重建工程闸址方案优选

穆棱河作为鸡西的"母亲河"、重要的水源地,对地区的经济发展起着重要的作用。鸡冠山水毁渠首枢纽工程,坐落于鸡东县城西8.00km鸡西市郊内穆棱河上,担负着鸡林灌区41.33km2水田的灌溉任务。闸址的优选分析,对工程使用功能的实现将起到事半功倍的作用。渠首水毁重建工程设计提出4种闸址方案进行选择分析,最终推荐方案Ⅲ为优选方案。重建的鸡冠山渠首枢纽工程,在满足灌区灌溉的同时,也是《穆棱河流域城子河综合治理工程》景观湿地水位保证的重要控制工程。     

王快水库除险加固工程溢洪道闸址优化设计

对王快水库溢洪道闸址下移40m进行方案比较,推荐了现状闸址方案。并对闸址进行了优化设计,优化后闸址较现状闸址下移15m。优化后闸室坐落在微风化或新鲜岩石上,两岸岩体宽厚,风化较轻,两岸绕渗问题亦易于解决。     

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。