关于土坝劈裂灌浆若干问题的思考

土坝劈裂灌浆建造防渗泥墙技术具有适用范围广、防渗效果显著、就地取材、节省投资、施工机械轻便和施工条件限制少等诸多优点，因而10多年来在我省中小型水库土坝防渗加固中得到广泛应用但要真正做好劈裂灌浆，使土坝防渗达到预期效果确非易事。根据10多年来的劈裂灌浆实践，针对我省目前在劈裂灌浆设计、施工中存在的误区，提出设计参数及其取值范围，指出如何正确理解土坝劈裂灌浆成墙过程，总结出为确保灌浆效果在施工中应注意的关键工艺措施。     

劈裂灌浆技术在风田水库主坝加固中的应用

列举了风田水库土坝采用劈裂灌浆技术加固前后土坝渗透系数的变化，说明劈裂灌浆技术在土坝加固应用中的可行性及其良好效果。     

劈裂灌浆技术在王瑶水库土坝加固中的应用及其效果

劈裂灌浆是处理坝堤病险隐患的一项先进技术,其效果好,施工简单,造价低,我省已在多处土坝加固中应用。如王瑶(大(二)型)水库土坝1988年劈裂灌浆后一直高水位运行,再未出现异常,效果满意。今再发表王瑶水库及宝鸡市8座水库应用劈裂灌浆技术加固土坝的两篇文章,以使同志们对劈裂灌浆技术有进一步了解,并推广应用。     

劈裂灌浆技术在土坝加固处理中的应用与效果

在土坝的碾压施工中，由于各种原因造成土坝坝体碾压不密实、土体渗透系数偏大等质量问题。影响工程正常运行或存在安全隐患。该文结合我省一工程实例探讨劈裂灌浆技术在土坝加固处理中的应用与效果。     

土坝劈裂灌浆技术在风田水库主坝加固中的应用

该文探讨了土坝劈裂灌浆技术在风田水库主坝加固中的应用,认为劈裂灌浆技术是处理土坝隐患效果最好的措施。     

浅谈土坝劈裂灌浆有关技术问题的处理

土坝劈裂灌浆技术是一项行之有效的病险水库土坝防渗处理技术,本文针对劈裂灌浆工程中碰到的一些问题进行阐述,希望在土坝劈裂灌浆技术的应用中起到一定参考和借鉴作用。     

有关劈裂灌浆期土坝坝体的稳定问题

随着土坝坝体劈裂灌浆技术的推广和普及,这项技术在土坝及堤防隐患的处理中起着越来越重要的作用。但是,由于劈裂灌浆是沿坝轴线布孔,在灌浆的后期坝体一般均沿坝轴线劈开,但此时劈裂缝中的泥浆还未充分固结,其抗剪强度基本等于零,所以灌浆期的坝体稳定问题,是值得重视的问题。现就劈裂灌浆期的土坝坝体稳定问题作一分析。     

劈裂式灌浆技术在水库土坝中的应用初探

通过对小河口水库土坝进行劈裂式灌浆的试验与施工，总结了在土坝中实施劈裂式灌浆的施工程序，施工方法，施工参数和技术要求。     

对土坝劈裂灌浆两个问题的分析

在我国，土坝劈裂灌浆技术的应用实践已积累了丰富经验，取得了很大的发展，现在已成功地运用到高土石坝、窄心墙坝、湿陷性黄土坝等土石坝上．但是运用劈裂灌浆技术在少数病险坝的处理上，由于种种原因，也发现了一些问题．如有的土坝灌浆处理后效果不持久，少则几年、多则十几年又“旧病复发”；有的土坝劈裂灌浆处理几年、甚至十几年后，钻孔取样发现，某一高程的浆脉仍然含水量高，处于软塑状态．由此对劈裂灌浆技术加固土坝的抗渗能力产生怀疑．本文就上述问题，做如下分析．１劈裂灌浆的持久性问题１．１必须保证浆脉冲填坝土所形成的…     

高水位运行下高土坝的劈裂灌浆施工实践

土坝劈裂灌浆技术以往大都在坝高低于５０ｍ的均质均和宽心墙坝中使用，且要求在水库低水位期进行。１９９７年广东省普宁市三坑上水库土坝防渗加固则采用劈裂浆为主，结合一结传统的灌浆工艺，对高５５ｍ的土坝在汛期持续高水位情况下进行劈裂灌浆施工，并取得了成功，为今后中，高土坝防渗加固提供了实践经验。     

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.     

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.     

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。     

Impacts of Microcystis on algal biodiversity and use of new technology to remove Microcystis and dissolved nutrients

Cyanobacteria often dominate eutrophic lakes, outcompeting green algae that are required by fish and zooplankton. This study was undertaken to ascertain the impact of the cyanobacterium, Microcystis, on algal biodiversity. Under laboratory conditions, we found that the presence of Microcystis decreased phyla richness by 58%, phyla evenness by 47%, genera richness by 66% and genera evenness by 51%. Analysis by mixed anova s demonstrated a significant interaction between treatment and time and confirmed a significant reduction in richness and evenness of phyla and genera. We also conducted a phosphate restriction assay on the algae in Mason Lake (Irvine, CA, USA) and found that the threshold needed for algal growth there was 0.02 mg L^?1 PO₄. A pilot study was then conducted to test the effectiveness of the Blue Pro? water treatment facility in removal of this colonial organism from Mason Lake, in addition to removal of dissolved nutrients required for its growth. We measured a 97% reduction in Microcystis cells, a 72% reduction in chlorophyll‐a, and a 96% reduction in phosphate after just one 10 min cycle through the unit. Our study demonstrated that removal of Microcystis colonies may allow green algae to increase in numbers. This may improve algal biodiversity, which will benefit zooplankton and fishes.     

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.     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

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。     

簸箕李引黄灌区水沙分布及优化调度的经验

灌区利用水沙观测所取得的资料和试验数据，运用水沙运动力学理论，总结分析和揭示了灌区水沙分布的规律和特点。在此基础上，结合灌区的实际运行情况，围绕减少骨干渠道的淤积进行探讨、研究，进而，优化水沙调度方案。该方案实施后，骨干渠道减旅伴效果明显，取得了成功的经验。     

小湾水库大坝防渗面板及其裂缝的加固处理

小湾水库大坝防渗面板整体抗渗性能差,且存在多条裂缝,通过对面板钢丝网喷涂丙乳砂浆加固处理及其裂缝修补,大坝渗漏量明显减少,且左岸上灌浆廊道内及大坝下游坝面92～93 m高程下廊道入口处原有小股射流全部消失.