数值模拟中微厚透水物糙率处理方法探讨

水利工程数值模拟计算中常需科学合理地概化实际工程中的透水物糙率,以反映透水物对水流的真实影响。对微厚透水物在流体数值模拟中的糙率处理方法进行了探讨,提出了一种新的糙率概化方法,即对原状透水物进行水槽试验,通过假定明渠长度将局部水头损失换算成沿程水头损失,再将换算数值应用于数模计算中。以东太湖吴江区第一水厂集中供水水源地的蓝藻隔离栏为例,通过具体工程实践介绍其使用方法,为不规则孔眼透水物以及使用过程中性质发生较大改变的透水物糙率率定提供了新的思路。     

梅州市黄塘河排涝泵站基坑排水设计

水利水电工程深基坑开挖时,必然会遇到地下水渗流问题,基坑排水将直接关系到工程能否顺利进行,基坑浸水后将影响到建筑物以后的安全,因此水利水电工程施工时,应重视基坑排水,应根据工程地质和水文地质情况确定适当的排水方案,并在基坑排水设计时应考虑到不利的情况。     

《建筑排水系统吸气阀》产品标准简介

介绍了《建筑排水系统吸气阀》产品标准的内容、意义,并对条款进行了分析和解释,特别指出吸气阀气密性试验前后压降10％,不是其泄漏值,而是确保其试验密封性的最低安全要求,也是进行重复试验时允许的最大偏差值的要求;认为制定了实验室测试方法和要求,可为吸气阀的使用提供可靠的保证,解决应用中的各种猜测和疑虑。介绍了吸气阀的应用。     

Analysis of scenarios for wastewater and urban drainage systems in Brazil based on an integrated modeling approach.

Brazil is currently facing widespread problems in the urban environment associated with inadequate wastewater and urban drainage systems, particularly for low-income communities. These problems are promoted by the rapid and often unplanned urbanization process in developing cities and are compounded by a lack of funding, absence of planning, ineffective institutional arrangements, and inappropriate policies to provide the framework for integrated wastewater and stormwater management. Because planning for the provision of wastewater and urban drainage systems is a complex task, an integrated-modeling approach is proposed to provide a practical methodology for sanitation and urban drainage planning in Brazilian cities. In the model development, as well as technical aspects, other aspects related to institutional, financial, socio-economic, environmental and public health issues were also taken into account.     

Non-deposition self-cleansing design criteria for drainage systems

Self-cleansing is a substantial aspect of the drainage systems in which it is desired to minimize the sediment deposition that can cause channel blockage and surcharge early overflows. In the conventional self-cleansing design criteria of drainage systems, a single value of velocity or shear stress is used based on experience. In the recent decades rather than using a single value, non-deposition design concept has been further modified to develop self-cleansing models based on higher number of parameters considering flow, fluid, sediment and channel characteristics. However, non-deposition self-cleansing models have been mostly developed for circular channels, and none of the models considers yet the effect of channel cross-section although some models take into account the pipe diameter, hydraulic radius and cross-section area as independent variables. In this study, a self-cleansing model considering the effect of cross-section by a shape factor available in the literature is developed to determine the non-deposition particle Froude number for bed load sediment transport. The model is developed using experimental data of circular, rectangular and U-shape channel cross-sections from the literature; and data of trapezoidal channel cross-section from experiments carried out in this study. For validation of the model, data collected in this study is used together with four different sources of data taken from the literature. Validation of the model for each cross-section data shows its wide range applicability in terms of different channel cross-sections.     

Stormwater reuse: designing biofiltration systems for reliable treatment.

Stormwater reuse is increasing in popularity as a technique for overcoming water shortages in urban Australia. However, technology for the reliable treatment of stormwater for reuse is still not fully developed. This paper presents the first steps in refining biofilters for stormwater reuse. Six different filter media were selected, to target specific stormwater pollutants, as well as support plant growth. They were tested in the laboratory, where the filters were dosed three times per week with semi-synthetic stormwater for five weeks. Pollutant removal performance was monitored, and revealed that all soil-based filters performed similarly (while sand filters behaved somewhat differently). All filters removed more than 80% of solids and greater than 90% of lead, copper, and zinc. Three filter types were able to remove some phosphorus (particularly in the top 30 cm of the media). Apart from sand, all filter media were net producers of nitrogen, leading to an important conclusion that non-vegetated, soil-based filters are not suitable for targeting nutrients. However, since heavy metals are the primary pollutant of concern with respect to stormwater reuse for irrigation (the most popular end-use), it was concluded that biofilters may be promising technologies for treatment of stormwater for reuse.     

上海市排水小区地下水渗入量研究

介绍了排水小区地下水渗入量测试的基本方法。采用夜间最小流量法和用水量折算法 ,对上海市代表性排水小区地下水渗入量进行了实测和分析 ,确定了不同类型排水小区的渗入量范围。对区域渗入量试验中需要关注的问题进行了研讨。研究成果为推动渗入量研究、改进高地下水位地区排水系统的设计、维护与管理提供了依据     

The role of sludge conditioning and dewatering in the fate of nonylphenol in sludge-amended soils.

One of the main concerns associated with the recycling of biosolids to arable land is their contamination by organic pollutants, like endocrine disruptors. Conditioning and dewatering are usually the last steps of the sewage sludge treatment, before its further utilization. The choice of the specific conditioning/dewatering method may have an effect, not only on the amount of residues in the biosolids, but also on the fate of these compounds in amended soils. Anaerobically digested wastewater sludge was conditioned at lab-scale by means of physical and chemical methods and subsequently dewatered by centrifugation. The produced biosolids plus non-conditioned and non-dewatered sludges were amended separately to soil and spiked with 14C radiolabelled single isomer of nonylphenol. The persistence and leaching potential of nonylphenol after an incubation period of three months were correlated to the sludge treatment method. In comparison to non-conditioned sludge, 54% and 72% higher amount of pollutant residues were extractable when freeze-thawed and limed sludge, respectively, were used. Conditioning of sludge with cationic polymer decreased the leaching potential of nonylphenol in sludge-amended soils, while liming increased it. Fractions of the model compound recovered as extractable and bound residues were analyzed in order to interpret nonylphenol fate.     

大面积工业厂房的雨水系统选择

结合不同的大屋面材料、形状 ,介绍了长天沟外排水、重力流悬吊管、敞开系统内埋地管式、封闭系统内埋地管式及压力流 (虹吸式 )屋面雨水系统的特点及适用性。另外对轻钢结构厂房雨水系统设计应注意的一些问题作了说明     

An alternate approach for transient flow modeling in urban drainage systems

Implementing control structures such as gates at suitable locations in the urban drainage network enables its improved utility by actively controlling and optimizing the flow during a flood event. The successful operation of the control structure is fully governed by the suitability and efficiency of the control strategy adopted, which in turn depends on the response characteristics of the urban drainage system under different flow conditions. For an extreme rainfall event, it is necessary to model the transient flow in the urban drainage system. However, such an exercise is mostly restricted by the limited data and lack of in-depth survey of urban drainage systems in most of the developing countries like India. Taking this into consideration, an alternate approach has been presented in this paper for modeling the transient flow in the urban drainage system under limited data availability. The results obtained have also been compared with the finite difference model using four-point implicit scheme in time domain. The developed model can be used for the computation of temporal distribution of water surface profile with special consideration of lateral inflow. The application has been demonstrated by applying it to a representative catchment in Mumbai, India.     

基于不规则三角网的河网提取算法

本文提出了一种基于不规则三角网(Triangulated Irregular Network,TIN)的河网水系提取算法。讨论了河网水系的结构模式,包括河网水系的组织结构、层次结构和拓扑结构,并给出了河网水系描述的拓扑数据结构。在分析TIN中三角形各边的汇流特性基础上,依据矢量代数理论,讨论了三角形各边和水流方向的关系,并给出了各边汇流特性的判断准则。基于上述理论,设计了TIN的河网水系提取算法,并通过实例进行了分析验证。     

浅谈中西方在水电站排水系统设计中的差异

水电站排水系统是水电站辅助系统设计中比较关键的系统,是关系到电站安全可靠运行的重要保障。通过介绍某西方咨询公司编制的可研报告所推荐的电站排水系统的设计原则和方法,并分析对比其与中国设计标准体系下电站排水系统的设计原则和方法存在的差别,对国际水电项目在排水系统的设计原则方面提出新的探讨。     

基于热力学原理的土体动力模型阈值应变研究

基于热力学基本定律,建立了塑性中心移动为直线和骨架曲线两种情况下Hardin-Drnevich模型的能量耗散函数表达式,并与具体试验相结合讨论了不同动应变水平下反滤料、细堆石料、粗堆石料的能量耗散机制。发现筑坝堆石类无黏性材料的动力特性存在2个应变阈值,定义为第1和第2阈值应变,其对应的割线模量与最大动剪模量之比分别为大于0.97及0.5~0.8之间。从工程应用的角度看,若土体动应变小于第1阈值应变,则可直接采用最大动剪模量及常阻尼比进行土体动力分析;第2阈值应变与传统意义上以孔隙水压力升高或体积变化为标准定义的门槛应变相当。     

基于Nash 瞬时单位线法的渗透坡面汇流模拟

基于Nash瞬时单位线法,结合Horton土壤入渗经验模型,并考虑植被对降雨的截流作用,建立了渗透坡面汇流计算的数学模型。以矩形坡面为研究对象,基于其汇流时间-面积特性,结合等流时线法,推导建立了Nash瞬时单位线参数n、K的确定方法。其中,参数n的值为1.0,K的值与坡面汇流时间相等,相当于单一线性水库。应用本文建立的模型,对林地渗透坡面降雨径流进行计算,并与实测值进行比较。结果表明,计算值与实测值的变化趋势基本吻合,初步验证了本文方法的合理性。     

基于Nash瞬时单位线法的渗透坡面汇流模拟

基于Nash瞬时单位线法,结合Horton土壤入渗经验模型,并考虑植被对降雨的截流作用,建立了渗透坡面汇流计算的数学模型。以矩形坡面为研究对象,基于其汇流时间-面积特性,推导建立了Nash瞬时单位线参数n、K的确定方法。其中参数n的值与坡面汇流时间-面积曲线指数相等,K的值与坡面汇流时间相等。应用本文建立的模型,对林地渗透坡面降雨径流进行计算,并与实测值进行比较。结果表明,计算值与实测值的变化趋势基本吻合,初步验证了本文方法的合理性。     

Numerical simulation of transient flow in horizontal drainage systems

A numerical simulation model based on the characteristic-based finite-difference method with a time-line interpolation scheme was developed for predicting transient free surface flow in horizontal drainage systems. The fundamental accuracy of the numerical model was first clarified by comparison with the experimental results for a single drainage pipe. Boundary conditions for junctions and bends, which are often encountered in drainage systems, were studied both experimentally and numerically. The numerical model was applied to an actual drainage system. Comparison with a full-scale model experiment indicates that the model can be used to accurately predict flow characteristics in actual drainage networks.     

给水厂污泥脱水技术改造设计方案研究

针对以黄河水为原水的给水厂污泥进行了混凝及优选比阻调理试验,结果表明:当进行给水厂污泥脱水技术改造方案设计时,可以不经过混凝处理,直接利用电厂粉煤灰作为比阻调理剂。细粉煤灰的最佳投加率为20%,粗粉煤灰的最佳投加率为30%,使污泥比阻由1013数量级降至1010数量级,改善了污泥脱水性能,所得滤饼含水率仅为40%~50%,易于剥离,能耗低,所得滤液的色度、浊度、CODMn均达到可直接回用标准。当进行技改工程设计时,建议选用带式压滤机或板框压滤机,既适应粉煤灰调理剂,又可节约投资。     

Performance indicators for the efficiency analysis of urban drainage systems.

Performance indicators implemented in a decision support system (DSS) for the technical, managerial and economic evaluation of urban drainage systems (UDS), called MOMA FD, are presented. Several kinds of information are collected and processed by MOMA FD to evaluate both present situation and future scenarios of development and enhancement. Particular interest is focused on the evaluation of the environmental impact, which is considered a very relevant factor in the decision making process to identify the priorities for UDS improvements.     

改良型透水铺装对弱透水土质地区SS的去除效果试验

为研究适用于弱透水土质的改良型透水铺装对典型雨水径流污染物悬浮固体(SS)的去除效果,以嘉兴地区的淤泥质黏土为土基层制作试验装置,以人工模拟降雨的方法模拟并检测不同降雨重现期条件下改良型透水铺装装置削减径流污染物SS的效果,并以常规透水铺装和普通路面作为对比。结果表明:较小的降雨重现期更有利于透水铺装对SS的去除;弱透水土质条件下改良型透水铺装在对SS的去除过程中,不但去除率高于常规透水铺装,去除速率也得到了提高;在降雨重现期1 a条件下,改良型透水铺装平均每分钟比常规透水铺装多去除29.82%的SS。     

基于试验遗传算法的平原圩区除涝排水系统最优规划

平原圩区除涝排水系统最优规划是一个多维、非线性复杂系统优化问题。本文提出基于试验优化设计思想的试验遗传算法,即在标准遗传操作中增加了均匀设计、正态随机和摄动调优等试验操作技术。某圩区排水系统最优规划实例表明,与可分规划法及简单遗传算法相比,试验遗传算法能严格满足系统约束条件,且操作简单,计算效率更高。由于该算法兼顾了整体空间的种群多样性和局部空间极小值的搜索效率,同时能根据需要自动调整计算精度,因此较易获得复杂问题的全局最优解。