飞来峡大坝安全监测系统技术改造

主要介绍了飞来峡大坝安全监测系统原有的不足及改造后的优点，探索大型防洪水利枢纽大坝安全监测自动化的目标及特点。     

万家寨水利枢纽大坝安全监测系统改造设计

万家寨水利枢纽是黄河中游干流上的大型水利枢纽工程。针对大坝变形、渗流及自动化监测系统存在的问题，对大坝安全监测系统进行了改造设计，内容包括新增和改造变形和渗流监测项目，改造和升级自动化系统软件和硬件。通过改造，万家寨大坝安全监测系统将成为一个项目齐全、先进可靠的安全监测系统。     

汤河水库大坝安全监测自动化系统的故障诊断系统分析

汤河水库位于辽阳市弓长岭区汤河乡境内,建于太子河一大支流——汤河干流上,是一座以防洪、城市和生活供水为主,兼顾灌溉、养鱼、发电等综合利用的国家大(2)型水利枢纽工程。汤河水库大坝安全监测自动化系统实现了坝体浸润线的自动化观测,由于它的及时性和可靠性,已经成为大坝的安全性观测不可或缺的最主要的手段。结合工作实际,对大坝安全监测自动化系统的故障诊断进行了系统的分析。     

乐昌峡水利枢纽安全监测系统及其应用

乐昌峡水利枢纽是一座以防洪为主,兼有发电和改善生态环境等综合效益的大型水利枢纽工程,水工安全监测对枢纽运行工程安全起预防保障作用。该文从水工建筑物安全监测自动化系统总体结构、应用成果分析等方面,阐述了安全监测系统在乐昌峡枢纽的应用。     

新疆首套大坝自动化监测系统投入运行

日前 ,新疆第一套大坝安全监测自动化系统在大山口水电厂水库投入运行 ,标志着大山口大坝的安全监测已达到国内先进水平。大山口水库位于天山南麓 ,是开都河上兴建的第一座以发电为主兼顾防洪的中型水利枢纽。大山口大坝高 72 m,是全疆最高的混凝土重力拱坝。大坝施工时因种种原因未建立规范、完善的监测设施 ,自 1991年蓄水运行以来 ,监测系统先天不足 ,设施陈旧、简陋 ,监测仪器和手段原始 ,监测精度低。 2 0 0 1年 11月 ,大坝安全监测自动化系统安装完毕并投入试运行。该系统采用南京水利水文自动化研究所研制的 DG型分布式数据采集系统…     

桃林口水库大坝监测自动化系统改造方案

桃林口水库位于滦河支流青龙河上,是一座集供水、发电、灌溉和旅游等多种功能于一体的大型水利枢纽工程,总库容为8.59亿m~3。水库大坝安全监测项目分内部观测和外部观测两部分。大坝安全监测采用自动化系统,从建成到现在已运行十多年,设备严重老化,工作性能下降,已经严重影响大坝安全     

南京南瑞集团公司中标万家寨水利枢纽大坝安全监测自动化系统工程

在黄河万家寨水利枢纽工程大坝安全监测自动化系统招投标过程中，黄河万家寨水利枢纽有限公司经考察和初评后邀请南京南瑞集团公司等３个单位投标，历经１年多的评标和考查，南瑞集团公司因技术方案先进、综合实力强已于１９９３年３月１８日中标。方家寨水利枢纽工程大坝安全监测自动化系统采用南瑞集团公司的ＤＡＭＳ—４型智能分布式系统。整个工程将于１９９９年底投用。南京南瑞集团公司中标万家寨水利枢纽大坝安全监测自动化系统工程     

“北斗天眼”守护山美水库大坝 我省首次运用北斗卫星进行水库大坝安全监测

正2016年4月,泉州市山美水库管理处与相关科研单位合作开发了基于北斗的大坝安全监测系统,并成功应用于山美水库大坝安全监测。这是福建省首次运用北斗卫星进行水库大坝安全监测。山美水库位于福建省四大江之一的晋江东溪中游,是晋江流域一座集防洪、供水、灌溉、发电、生态等综合利用的大型水利枢纽工程,被誉为"泉州人民的生命库"。作为福建省唯一的国家一级水利工程管理单位,多年来,山美水库管理处牢固     

东北地区大坝安全监测技术的展望

通过对东北地区大坝安全监测技术与国内外发展水平的比较分析,提出了目前东北电网大坝安全监测工作存在的主要问题及大坝安全监测自动化技术的发展方向.建议在加快大坝安全监测自动化工作的同时,积极开展观测资料分析及坝体缺陷诊断技术的研究,为大坝加固、防洪调度提供明确的技术参数.     

小浪底大坝安全监测自动化的实施

小浪底水利枢纽拥有目前国内已建工程中规模最大的观测系统,大坝安全监测自动化程度和应用水平在同业具有领先地位,本文总结和论述了小浪底大坝安全监测自动化实施的项目,包括自动化数据采集系统、人工观测数据自动录入、传输系统和大坝安全监控系统等,并对实施过程中的经验和不足进行初步探讨,以期对其他工程项目安全监测自动化实施提供借鉴。     

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.     

Toxic effect of the mosquito killer, S-Deltamethrine, on the development and respiratory electron transport system activity of the embryos of bream (Abramis brama L.), roach (Rutilus rutilus), barbell (Barbus barbus) and pike (Esox lucius)

The effect of the insecticide, S-Deltamethrine (DM, LC₅₀ for mosquito larvae: 0.02 ppb), in the concentration range between 0.025 and 2500 ppb was examined in both embryogenesis and embryonic evolution of the electron transport system (ETS) of the bream, roach, barbel and pike. A 0.025 ppb concentration of DM caused 10-25% death of the embryos in the first 2 days of incubation. Fifty per cent of the roach embryos died by the end of a 144 h incubation period when the concentration was 0.025 ppb. In 2.5 ppb, 50% of the embryos died after 120 h. In 25 ppb, 50% death was registered after 96 h, and in 250 and 2500 ppb, 50% death was detected after 48 h. Fifty per cent of the barbel embryos died after a 48 h long incubation time in 250 and 2500 ppb. The same mortality was detected for the embryos of pike in 2500 ppb after a longer (148 and 168 h) incubation time. Half of the bream embryos died after 24 and 48 h at a concentration of 2500 ppb. Larvae showed a more sensitive response to treatments than did embryos. After hatching, 30-84% of the larvae died in 0.025 ppb. Compared to embryos, larvae moved less in a concentration of 0.025 ppb and could not swim as easily as controls. In a concentration >0.25-2.5 ppb, larvae were passive and often malformed. S-Deltamethrine inhibited ETS activity in a concentration-dependent manner. Electron transport system activity of larvae was reduced by 50% in 250 ppb concentration.     

温排水对陡河水库富营养化影响的预测研究

研究电厂温排水对陡河水库富营养化的影响。陡河水库属我国北方地区多功能浅水型水库 ,已运行 4 0余年。库区水情较复杂 ,热影响严重 ,营养盐偏重 ,具有一定的典型意义 ,可供类似湖库研究热影响问题参考。全文分三篇刊登 :1.陡河水库热影响与富营养化调查及生物学评价 ;2 .温排水对陡河水库富营养化影响的预测研究 ;3.陡河水库富营养化趋势分析与防治对策     

软土卸荷强度试验方法探讨及试验研究

通过不同固结、剪切路径,对广州典型软土进行了卸荷抗剪强度试验,试验结果显示,不同的试验方法得到不同抗剪强度参数。不同试验方式下,土样卸荷后的抗剪强度指标都低于加荷下的抗剪强度指标;对基坑工程而言,采用DCU（侧向卸荷三轴试验）更符合实际情况,鉴于该试验方法较难,可采用DGK（先预压固结后卸荷至不同固结压力再进行快剪试验）得到的指标来代替。试验结果还表明：卸荷状态下土体应力应变曲线仍为双曲线形式,且曲线为加工硬化型;在相同的围压下,卸荷强度小于加荷强度;初始切线卸荷模量小于初始切线加荷模量,即用加荷下的加荷模量来代替卸荷下的卸荷模量将会使得工程偏于危险。     

Catchment‐scale controls on groundwater–surface water interactions in the hyporheic zone: implications for salmon embryo survival

The spatial and temporal variability of groundwater–surface water (GW–SW) interactions in the hyporheic zone were investigated in a semi‐pristine upland salmon spawning catchment (Girnock Burn) in the Cairngorm Mountains, northeast Scotland. Stream and hyporheic water quality (200–300 mm depth) were monitored fortnightly at 16 spawning locations distributed throughout the catchment. Hydrochemical tracers were used to assess local GW–SW interactions. Stratified streambed incubators (50–300 mm) provided information on salmon embryo mortality at a sub‐set of ten locations. Hyporheic water quality varied both temporally and spatially according to local GW–SW interactions. It was possible to categorize sites into three broad typologies reflecting local stream–aquifer interactions: (1) groundwater‐dominated; (2) surface water‐dominated; and (3) sites exhibiting transient water table features. Groundwater upwelling occurred in areas where low permeability glacial moraine features caused substantive valley constriction. These locations were also conducive to accumulation of spawning grade gravels and consequently were utilized heavily by spawning salmon. Long residence groundwater was typically characterized by low dissolved oxygen (DO), of sufficiently low quality to be detrimental to salmon embryo survival. At sites dominated by surface water, hyporheic DO remained high throughout and rates of embryo survival were correspondingly high. Survival rates were also high at sites where hydrochemical characteristics indicated a transient water table. This is probably attributable to the hydrological conditions which resulted in increasing DO concentrations towards hatch time when embryo oxygen demand is at its maximum. The degree to which the findings of this study are directly applicable to other catchments is currently unknown. However, similar effects have been observed elsewhere, and based on the information presented here, there are clear implications for fisheries managers who may wish to consider the use of surface incubation facilities to negate the effects of low DO groundwater upwelling where it dominates available spawning habitat. It is suggested that future research should aim to integrate across spatial scales and disciplines to obtain a better understanding of the ways in which hillslope and riparian zone hydrology affect GW–SW interactions, hyporheic zone processes and stream ecology. © Crown copyright 2005. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.     

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。     

NUMERICAL STUDY OF WAVE EFFECTS ON SURFACE WIND STRESS AND SURFACE MIXING LENGTH BY THREE-DIMENSIONAL CIRCULATION MODELING

1. INTRODUCTION Coastal and continental shelf regions are characterized by intensive interaction between wave and current. These regions are of great economic significance to mankind. Therefore, the modeling of wave and current as well as their mutual int…     

Fish species richness is a key predictor of community biomass and productivity in littoral regions of Severn Sound,an embayment of southern Georgian Bay,Lake Huron

Catches from standardized littoral electrofishing (EF) surveys (1990–2016) at various locales in Severn Sound, Georgian Bay, were analyzed. Catches were adjusted for size-selectivity using published results of laboratory immobilization experiments. Adjusted abundance-mean size relationships were consistent with the metabolic theory of ecology where body size has a central role in structuring community features. Relationships among species richness and areal estimates of biomass and annual production of the adjusted catches were assessed. Richness was the key variable driving other community metrics and was, in turn, largely driven by habitat fetch metrics and sampling time of day. Richness, biomass, and production decreased with increasing maximum effective fetch. Richness increased with time after sunset. Year and locale had smaller roles in variation of community metrics with more vegetated/ less urbanized areas having higher values. Higher fish production is expected in sheltered areas where the contributions of allochthonous and benthic primary production are expected to be greater. Further analyses using additional EF datasets from Great Lakes’ littoral zones should increase understanding of the differences between littoral and offshore fish productivity and help guide management of littoral habitats to ensure healthy fish communities.     

Pesticide residues in Volta Lake, Ghana

The Volta River basin comprises ≈ 70% of mainland Ghana, being inhabited by a majority of the country's population. The purpose of this study was to analyse water and sediment samples at six locations in Volta Lake for residues of persistent organochlorine pesticides. Residues were extracted by use of two types of extractions, including a standardized solid phase extraction procedure for water samples and a Soxhlet extraction procedure for sediment samples. All samples were analysed by gas chromatography. Lindane and endosulfan were identified in concentrations ≤ 0.008 p.p.b. and 0.036 p.p.b., respectively, in water, and ≤ 2.3 p.p.b. and 0.36 p.p.b., respectively, in sediments. Dichlorodiphenyltrichloroethane and dichlorodiphenyldichloroethylene were also found in sediment samples (in concentrations ≤ 9.0 p.p.b. and 52.3 p.p.b., respectively). No significant contamination was noted in the lake. The distribution of pesticide residues in water and neighbouring sediment are briefly discussed. Different bioconcentration factors obtained in this study allowed the confirmation of the complex processes already reported in the literature regarding the partitioning of chemicals between sediment and water.