基于SWMM的排水管网系统模拟分析技术

道路积水是排水管网系统功能失效的宏观反映.为了防止并减轻此类灾害,应用系统建模仿真以及情境分析方法对排水管网系统进行分析.以镇江市中心城区解放南路雨水排放子系统为实例,采用排水管网建模仿真软件SWMM和典型情境分析对该系统运行的总体性能和瓶颈进行了模拟分析,为排水管网系统的改造策略提供科学参考.     

Identifiability analysis in conceptual sewer modelling

For a sufficient calibration of an environmental model not only parameter sensitivity but also parameter identifiability is an important issue. In identifiability analysis it is possible to analyse whether changes in one parameter can be compensated by appropriate changes of the other ones within a given uncertainty range. Parameter identifiability is conditional to the information content of the calibration data and consequently conditional to a certain measurement layout (i.e. types of measurements, number and location of measurement sites, temporal resolution of measurements etc.). Hence the influence of number and location of measurement sites on the number of identifiable parameters can be investigated. In the present study identifiability analysis is applied to a conceptual model of a combined sewer system aiming to predict the combined sewer overflow emissions. Different measurement layouts are tested and it can be shown that only 13 of the most sensitive catchment areas (represented by the model parameter 'effective impervious area') can be identified when overflow measurements of the 20 highest overflows and the runoff to the waste water treatment plant are used for calibration. The main advantage of this method is very low computational costs as the number of required model runs equals the total number of model parameters. Hence, this method is a valuable tool when analysing large models with a long runtime and many parameters.     

Surface models for coupled modelling of runoff and sewer flow in urban areas.

Traditional methods fail for the purpose of simulating the complete flow process in urban areas as a consequence of heavy rainfall and as required by the European Standard EN-752 since the bi-directional coupling between sewer and surface is not properly handled. The new methodology, developed in the EUREKA-project RisUrSim, solves this problem by carrying out the runoff on the basis of shallow water equations solved on high-resolution surface grids. Exchange nodes between the sewer and the surface, like inlets and manholes, are located in the computational grid and water leaving the sewer in case of surcharge is further distributed on the surface. Dense topographical information is needed to build a model suitable for hydrodynamic runoff calculations; in urban areas, in addition, many line-shaped elements like houses, curbs, etc. guide the runoff of water and require polygonal input. Airborne data collection methods offer a great chance to economically gather densely sampled input data.     

城市排水管道开挖与非开挖修复的综合成本分析

排水管道的非开挖修复因工期短、施工对道路交通影响小,近年来在国内开始得到重视与应用。然而,非开挖修复的直接成本较高限制了新技术的推广。对近5年来上海城区完成的10段排水管道修复工程的直接成本进行统计分析,同时对其主要社会成本进行了量化,据此对不同类型修复工程的综合成本进行了分析比较,认为就综合成本而言,非开挖修复优于开挖修复,有必要通过政策调控推进非开挖修复的应用。     

Impact of sewer condition on urban flooding: an uncertainty analysis based on field observations and Monte Carlo simulations on full hydrodynamic models

In-sewer defects are directly responsible for affecting the performance of sewer systems. Notwithstanding the impact of the condition of the assets on serviceability, sewer performance is usually assessed assuming the absence of in-sewer defects. This leads to an overestimation of serviceability. This paper presents the results of a study in two research catchments on the impact of in-sewer defects on urban pluvial flooding at network level. Impacts are assessed using Monte Carlo simulations with a full hydrodynamic model of the sewer system. The studied defects include root intrusion, surface damage, attached and settled deposits, and sedimentation. These defects are based on field observations and translated to two model parameters (roughness and sedimentation). The calculation results demonstrate that the return period of flooding, number of flooded locations and flooded volumes are substantially affected by in-sewer defects. Irrespective of the type of sewer system, the impact of sedimentation is much larger than the impact of roughness. Further research will focus on comparing calculated and measured behaviour in one of the research catchments.     

排水管道常用封堵方法介绍

在修理管道前,必须对正在通水的管道进行封堵.封堵管道,尤其是封堵大型排水管道是一项既困难又危险的工作,我国的管道封堵技术目前还比较落后.结合工程实际介绍了国内外常用的各种封堵方法,以及在施工中应采取的安全措施.     

Parameter sensitivity analysis for activated sludge models No. 1 and 3 combined with one-dimensional settling model.

The aim of this study was to suggest a sensitivity analysis technique that can reliably predict effluent quality and minimize calibration efforts without being seriously affected by influent composition and parameter uncertainty in the activated sludge models No. 1 (ASM1) and No. 3 (ASM3) with a settling model. The parameter sensitivities for ASM1 and ASM3 were analyzed by three techniques such as SVM-Slope, RVM-SlopeMA, and RVM-AreaCRF. The settling model parameters were also considered. The selected highly sensitive parameters were estimated with a genetic algorithm, and the simulation results were compared as deltaEQ. For ASM1, the SVM-Slope technique proved to be an acceptable approach because it identified consistent sensitive parameter sets and presented smaller deltaEQ under every tested condition. For ASM3, no technique identified consistently sensitive parameters under different conditions. This phenomenon was regarded as the reflection of the high sensitivity of the ASM3 parameters. But it should be noted that the SVM-Slope technique presented reliable deltaEQ under every influent condition. Moreover, it was the simplest and easiest methodology for coding and quantification among those tested. Therefore, it was concluded that the SVM-Slope technique could be a reasonable approach for both ASM1 and ASM3.     

A software-based sensor for combined sewer overflows

A new methodology for online estimation of excess flow from combined sewer overflow (CSO) structures based on simulation models is presented. If sufficient flow and water level data from the sewer system is available, no rainfall data are needed to run the model. An inverse rainfall-runoff model was developed to simulate net rainfall based on flow and water level data. Excess flow at all CSO structures in a catchment can then be simulated with a rainfall-runoff model. The method is applied to a case study and results show that the inverse rainfall-runoff model can be used instead of missing rain gauges. Online operation is ensured by software providing an interface to the SCADA-system of the operator and controlling the model. A water quality model could be included to simulate also pollutant concentrations in the excess flow.     

Settlement as a driver for sewer rehabilitation

This paper assesses the influence of (differential) settlement on sewer system functioning. Based on historical data of the vertical position of sewer invert levels, tilt measurements and in-sewer inspection videos, settlement and settlement related influences are analyzed for a case study area in Amsterdam. The average settlement rate of this system was 4 mm/year. Given this settlement rate, it is shown that settlement significantly influences sewer system functioning within the lifetime of a sewer (system).     

Using decision analysis to determine optimal experimental design for monitoring sewer exfiltration with tracers.

The tracer methods developed to assess exfiltration from sewers in the European project APUSS (assessment of the performance of sewer systems) have a high degree of freedom with regard to the choice of tracer and the dosing strategy. These can lead to very different degrees of uncertainty in the measured exfiltration ratio. In this study, we demonstrate how to select an optimal experimental design using decision analysis, which accounts for this uncertainty and its associated costs. Although the results are site-specific, we can conclude generally that, when NaCl is used as the tracer, the accuracy of the exfiltration estimate is most sensitive to the amount of tracer used and the starting time of the experiment.     

建筑给排水管道噪声的分析与控制

对建筑给排水管道噪声产生与传播的原因进行了分析,并对控制建筑给排水管道噪声的相应措施进行了探讨.从设计和施工两方面出发,论述了给排水管道布置方面降低噪声的措施、给排水管材的选用及给水泵房的减振隔声等内容.     

地下排水管道流量检测技术进展

排水管道属于资金密集型市政基础工程.准确掌握管道内水流状况,是改善排水系统管理、科学制定管道系统改扩建方案的必要条件,也是今后利用先进技术建立管道系统模型、实现计算机实时控制的基础.系统总结了排水管道流量测试的常规技术,提出了适用性评估方法,介绍了目前国际上较为先进实用的排水管道流量检测设备及其在上海的应用,以期推动国内排水管道的流量检测与排水系统的管理水平.     

排水管道的点状修理

管道的非开挖修理可分为点状修理和整体修理两种。从总体上看,点状修理的质量不如整体修理,但由于其设备简单,造价较低,在目前我国管道维修经费普遍不足的情况下,仍然有很大的应用价值。介绍了排水管道点状修理的方法:嵌补法、注浆法、套环法、局部涂层法,并进一步分析了各种方法的优缺点及其在国内外的应用情况。     

A dynamic ventilation model for gravity sewer networks

To implement any effective odour and corrosion control technology in the sewer network, it is imperative that the airflow through gravity sewer airspaces be quantified. This paper presents a full dynamic airflow model for gravity sewer systems. The model, which is developed using the finite element method, is a compressible air transport model. The model has been applied to the North Head Sewerage Ocean Outfall System (NSOOS) and calibrated using the air pressure and airflow data collected during October 2008. Although the calibration is focused on forced ventilation, the model can be applied to natural ventilation as well.     

排水管道淤积状况模拟分析

针对排水管道中沉积物淤积状况判断的实际需求,利用上下游检查井的水位测试,并借助排水管网水力模型,可判断管道淤积状况。通过分析淤积特征,提出水位相对变化指标概念;构建小型案例,从管道淤积平均断面面积和淤积平均长度、管长、管径、坡度、流量、管道粗糙系数7个方面分析其对上下游检查井水位的影响。模拟结果表明,开泵后淤积管道上下游水位差变化比无淤积管道明显;淤积平均断面积和淤积平均长度均对管道上下游水位差具有影响;管道淤积程度越大,水位相对变化指标K值越大;当K≥2时,则可判断管道存在淤积,淤积面积为30%以上。     

上海市排水管道硫化氢腐蚀的探察与分析

城市污水中含有不同程度的硫酸盐,由于硫酸腐蚀和硫化氢直接腐蚀作用,对排水管道产生严重腐蚀。采用CCTV(闭路电视)检测系统对排水管道进行探察,确定腐蚀状况,确保在腐蚀早期进行修复。详细论述了硫化氢腐蚀的机理及影响因素,并阐述了控制硫化氢腐蚀的方法。     

苏州市姑苏区污水管道评估及维护效果分析

为改善苏州市姑苏区污水管道运行能力,提升福星污水处理厂污水处理效率,以及掌握该区域污水管道健康状况,结合CCTV检测技术对苏州市姑苏区宝带西路、南环西路、桐径北路、福运路、西环路段总长度约10.19km市政污水管道开展检测、评估、维护工作。实践表明,该地区污水管道经过维护后,排污能力有明显提升。     

城镇室外排水管道的一种新型高效断流装置

系统介绍了一种不破坏城镇室外排水管道地表和地下结构,能够安全、快速实施断流的装置.介绍了其基本原理、结构组成和使用方法.该装置采用组装式机械挡板结构,可完成管径600～2 400 mm城镇室外排水管道的快速、安全、无渗漏断流.与传统方法相比,可减少断流工程费用、人力资源和操作环节.     

应用导向钻进技术敷设污水倒虹管探讨

《给水排水》2004年第9期刊登了“导向钻(拖拉管)管道敷设工艺在市政工程中的应用”一文,作者在文章结尾提出自己的观点,认为拖拉管法能否在城市道路雨、污水管中应用值得探讨。笔者根据在实践中掌握的情况,认为该方法能够应用于污水倒虹管施工中,并能克服传统施工方法存在的问题。1导向钻进敷设倒虹管的技术特点导向钻进敷管法是非开挖敷设地下管线技术中的一种,在电信行业应用较早。其工艺流程主要有三个阶段:钻导向孔(见图1)→回拉扩孔、成孔→回拉敷管。它具有非开挖施工的共同优点,如无须断航等。此外,其钻孔轨迹是一条平滑的曲线,避免…