清淤淤泥的固结特性试验研究

太湖等湖泊开展清淤工程中产生的清淤淤泥常先放置于堆场,后经排水固结法处理为土地利用。设计处置方法前需了解淤泥固结特性,为预估沉降和固结速率提供参数。通过对固结仪进行改进,在满足对清淤淤泥进行固结试验的条件后,对3种不同初始含水率的清淤淤泥和1种重塑软土在小固结压力下进行试验,研究了清淤淤泥的固结特性和规律。结果表明:小固结压力下,清淤淤泥的压缩过程可用e-lgp曲线线性描述,压缩指数与初始含水率线性相关,清淤淤泥的固结系数随固结压力增加而增加(处于10-4cm2/s数量级),变化幅度较小,渗透系数极低(处于10-7 cm/s数量级)。     

Field monitoring of ripening of dredged material at three sites in the Netherlands (preliminary results)

Ripening of dredged material in a deposit is a natural ‘drying’ process by which raw dredged material transforms into soil. Ile aim of ripening is to obtain soil which complies with environmental legislations and geotechnical specifications for application in earthworks (e.g. dikes, noise reduction banks, landfill covers).The paper deals with the background and contents of a monitoring programme on the ripening behaviour of clayey, peaty, and sandy dredged material, and changes in chemical composition, especially of organic compouds, and leaching characteristics during ripening. The main objectives of the monitoring programme are (1) to develop a management system for the ripening process, (2) to quantify the input and output volumes of dredged material, and (3) to develop guidelines for the design of (transit) deposits. The results of the monitoring programme will also be used for calibration and validation of a computer model on ripening. Prelimanary results on ripening of clayey material and biodegration of PAH and mineral oil are presented. On the basis of these results it is expected that large volumes of slightly to moderately contaminated dredged material are suitable for beneficial use after ripening.     

A method of determining nonlinear large strain consolidation parameters of dredged clays

A method of obtaining the large strain consolidation parameters of dredged clays considering the influence of the initial water content is investigated in this study. According to the test results of remolded clays with high initial water contents reported by Hong et al.(2010), a relationship between the void ratio(e) and effective stress(σ') is established. Furthermore, based on the available permeability data from the literature, a new relationship between the permeability coefficient(k) and the ratio(e/eL) of the void ratio to the void ratio at the liquid limit(eL) is proposed. The new proposed expression considering the initial water content improves the e-k equation established by Nagaraj et al.(1994). Finally, the influence of the initial void ratio and effective stress on the large strain consolidation coefficient g(e) defined by Gibson et al.(1981) and k/(1+e) in large strain analysis is discussed. The results show that, under a constant effective stress, the value of k/(1+e) increases with the initial void ratio. The large strain consolidation coefficient shows the law of segmentation change, which decreases with the increase of the effective stress when the effective stress is less than the remolded yield stress, but increases rapidly with the effective stress when the effective stress is larger than the remolded yield stress.     

固化淤泥持水特性的微观机理研究

对不同初始含水率和水泥掺量的淤泥进行固化处理,采用滤纸法量测定固化淤泥的持水曲线,结合压汞法和模型预测分析其孔径分布曲线,研究固化淤泥持水特性的微观机理。结果表明:固化淤泥持水特性受水泥掺量和初始含水率的影响,微观孔径分布曲线为单峰,最可几孔径随着水泥掺量的增加而减小,可作为刻画孔径分布变化情况的理想参数。固化淤泥干燥过程中不发生收缩或收缩较小时,据模型预测得出的孔径分布曲线与实测曲线吻合较好;若发生明显收缩,预测得出的孔径分布曲线较实测曲线偏右。     

吹填土自重沉积固结特性试验研究

利用沉积柱试验研究了浙江海域沉积淤泥的自重沉积固结特性,探讨了泥水混合物初始密度、海水中阳离子类型及其浓度对自重沉积固结特性的影响.试验结果表明:该泥水混合物在50cm高的沉积柱中自重沉积阶段历时约3h,而自重固结阶段约持续到1～2d,自重沉积固结完成后的孔隙比介于2～3之间.泥水混合物的初始密度越大,泥浆自重沉积过程越慢,但固结完成后孔隙比越小.海水中盐溶液浓度越大或阳离子化合价越高,则泥浆沉积越快,固结后孔隙比越小.阳离子价位对该淤泥自重沉积固结特性的影响比溶液浓度更显著一些,在吹填工程实践中可考虑在泥水混合物中添加高价阳离子(如Ca2 )来提高自重固结速率和固结后密实度.该淤泥在0～2kPa应力范围的压缩曲线基本上是线性的,其对应的压缩系数约为1.3kPa-1.     

New technology of mechanical treatment of dredged material from Hamburg Harbour

Harbours and water ways can only fulfil their commercial task if there is always sufficient water depth for navigation. Environmental problems have started to influence dredging methods in recent decades. As a logical consequence of a policy giving high priority to environmental protection, Hamburg built the METHA plant (Mechanical Treatment of Harbour Sediments). METHA produces a clean sand product (grain size>63 μm) which is reused and a contaminated silt fraction (grain size < 150 μm) which is disposed presently. Previous investigations showed that the content of heavy metals and organic contaminants are primarily governed by the grain size. In 1995 Strom- und Hafenbau started a new investigation to produce a further fraction from the METHA silt which can be reused.The result of laboratory- and pilot-scale research showed the possibility of a further separation at 20 μm grain size. The best result was reached through a two-step separation made by hydrocyclons and spirals. The produced fraction (20–150 μm) is mainly quartz material with a low level of contamination. In February 1996 Strom- und Hafenbau decided to built a test plant in a technical scale. The capacity of the test-plant is 50 t/h based on dry substance The technical concept is integrated into the METHA concept. All aspects of technical feasibility, economy, environment and product reuse will be investigated in the test plant. The results of the early test phase will be presented.     

疏浚土排水固结过程中水质分析与污染性评价

为了分析疏浚淤泥排水固结过程中水质的污染特点,首先分析了土样的粒径组成及变化规律,了解其颗粒在渣场内的分选落淤特点,然后测试了水中各种有机、无机污染物的浓度及其变化过程。研究表明,疏浚土以粉粒、黏粒为主,比表面积大,吸附能力强;堆泥场内设置溢流堤、纵向隔堤,形成一定水头差的环形流道,从而有利于颗粒的落淤分选和污染物的吸附悬浮。水体、悬浮物和污染物等在负压抽吸作用下汇集进入排水管网而迁移排出。水质pH值变化很小,符合地表水质量标准;真空预压法可阻隔、过滤、吸附悬浮物、污染物,降低SS值,有利于氮的溶解、富集,总氮(TN)浓度变化不大;管道阻隔吸附、尾水沉淀、水生植物过滤等处治工艺对磷的溶解、吸附效果好,总磷(TP)减少,总溶解磷(TDP)增大,排放的余水中总磷(TP)未超湖、库Ⅲ类水质标准值;水质污染综合指数由基本合格提升为合格。     

长江上海段疏浚土有益利用的框架性建议

疏浚土是水利水运工程衍生的一种宝贵资源。在长江上海段,针对上游来沙量持续减少、河口砂土资源日趋紧缺、海洋倾倒区逐渐受控等新形势,开展港口航道疏浚土的有益利用是涉水部门的共同期望。依据工程现场调查资料,分析了长江上海段疏浚土有益利用的现状和存在的主要问题,结合新形势和新要求提出了疏浚土有益利用的框架性建议。研究分析表明,近10年来,长江上海段疏浚土有益利用实现了从无到有的历史性跨越,用于吹填造地的长江口深水航道疏浚土数量较为可观。但存在疏浚土利用方式单一、利用率总体偏低、相关体制机制尚未完善等诸多现实问题。为进一步提高长江上海段疏浚土的有益利用水平,提出框架性建议如下:加紧疏浚土有益利用关键技术研发,加快转变疏浚土资源化利用方式,以及加大疏浚土有益利用体制机制创新力度等。     

Use of hydrocyclone and flotation column for reducing the volume of contaminated dredged material.

As sediment contamination problems have recently been raised in Korea, the need for technologies to clean contaminants in sediments has increased. Although the recalcitrant organic matters and heavy metals in the contaminated sediments are of primary concern, large amounts of sediment makes the removal of the contaminants in them more difficult. In this study, the performance of hydrocyclone and flotation column was tested to reduce the volume of contaminated dredged materials (CDMs) prior to treating recalcitrant matters, such as various organic chemicals and heavy metals, in an integrated treatment system. When hydrocyclone was operated with 10% (w/v) solids concentration of the feed slurry, the total solids of upflow products were 4 to 7% (w/v) when the inlet pressure was changed from 1.0 to 2.0 kg/cm2. The volume reduction ratio of CDMs by hydrocyclone was approximately 90% (v/v). When the upflow products in hydrocyclone was then spiked with automobile transmission oil and fed to the flotation colum to see the performance of the column flotation on the volume reduction and the TPH removal, 44% of the TPHs in feed were removed at the tails and the volume reduction ratio of CDMs by column flotation was 18% at 200 L/min of wash water. The flotation column could be proposed as a potential preliminary treatment process of CDMs prior to subsequent biological treatments.     

长江口深水航道疏浚土处理现状及未来展望

长江口深水航道疏浚土产生量大,但如何对其进行更好地处理是水运工程领域的一大技术难题.利用大量工程现场资料,从长江口深水航道疏浚土的基本特性出发,对比分析了疏浚土处理现状,展望了疏浚土处理的发展模式.研究表明,长江口深水航道各工程阶段的疏浚土处理模式基本适应了不同维护水深条件下的疏浚土特点,总体仍以海洋倾倒为主.但在海洋倾倒区日渐严格控制、泥沙资源供需关系日趋紧张以及滩涂湿地面临侵蚀威胁等诸多新情势下,长江口疏浚土应遵循多用少抛的处理原则,利用疏浚土吹填造地、湿地保护等多途径处置将是未来长江口深水航道疏浚土处理的发展方向.     

疏浚泥固化过程中水分量的变化与 强度关系研究

采用计算含水率来表示固化疏浚泥中由于水泥反应引起的真实含水率变化,通过对7 d和28 d龄期水泥固化疏浚泥的含水率和无侧限抗压强度测定研究,发现固化疏浚泥无侧限抗压强度、计算含水率及其变化量均与水泥量之间存在良好的线性关系。因此,在工程应用中可以用计算含水率的变化量来推测固化疏浚泥的无侧限抗压强度     

卷材防渗漏工艺在水库除险加固中的应用

随着我国水利事业与高新技术的发展，高分子防水卷材在水利工程中的应用越来越广泛。通过青岛市崂山区晓望水库大坝的迎水面铺贴防水卷材的实例，分析研究在砌石坝上铺贴SBC聚乙烯丙纶复合防水卷材的切实可行的科学施工方法，为砌石坝除险加固工作提供一种经济便利的施工方案。图2幅，表1个。     

复合材料在发电厂的应用（续）

介绍了复合材料的类型、定义、及其特性。在此基础上，论述了复合材料在火力发电厂的应用情况。实践结果表明，复合材料不但能保留各组分的性能特点，且组分阃能相互协调，具有单一材料无法比拟的性能。复合材料工艺成本较低，使用该材料可节省大量的贵重金属，具有良好的经济性能。     

新材料、新技术、新工艺在韦水倒虹吸加固工程中的应用

通过论述韦水倒虹吸加固工程中新材料、新技术、新工艺的应用及探索，为水利水电工程结构加固改造提供了有益的实践经验。     

浅析平面闸门分节制造方案

一、工程概况 双桥闸工程位于安徽省宣城市,距宣城市5km,全闸共7孔,闸孔净宽8m.闸门型式为露定式平面定轮钢闸门,闸门外形尺寸为宽8100mm×高9700mm.考虑到运输、安装的便利,该闸门采用分三节制造的方案.由于受到现有交通条件的限制,如收费站的超宽道一般仅有4.5m,那么对于运输宽度超过6m的大中型闸门,一般采用分节制造的方案.而分节闸门一般都需要工地焊接、防腐,从而存在安装难度大、安装工期长且不易保证质量等缺点.双桥闸闸门采用独立的三节结构,每节闸门配有四个主滚轮,均衡受力,每节门叶自成整体,节间用止水橡皮连接,侧封水为一整体结构,分节后最大一节门叶的运输宽度为3.7m,既解决了大型闸门运输难的难题,又克服了分节闸门安装难度大、安装工期长的缺点,有效地保证了闸门的质量.     

纳米材料的进展及展望（续）

对纳米材料的基本概念、纳米材料的分类和纳米技术应用状况作了介绍。在此基础上，对纳米材料的研究和发展方向进行了展望和预测。     

平原河道节制闸混凝土老化研究与补强加固技术

聊城市地处黄泛冲击平原，主要骨干河道上的节制闸69％建于二十世纪六十年代后期，它们在防洪除涝、蓄水灌溉等方面发挥了重要作用。但因当时经济技术条件的限制，再加上30余年运行影响，闸体混凝土剥蚀、脱落严重，特别是水位变动频繁区剥蚀面积竟达100％，最大剥蚀深度5cm，部分受力筋遭腐蚀。笔者曾参加徒骇河王堤口节制闸的现场检测，经综合分析研究，提出了闸体混凝土补强加固技术方案，并进行了实际应用。经过近10年跟踪观测，修复部分至今未发现脱落、裂缝等问题。笔者认为补强加固方案既经济又实用，有一定的推广价值。