某景观河道水闸设计分析

水闸是一种低水头水工建筑物,在水利工程中应用十分广泛。结合工程实例,分析城市景观河道中的水闸设计需考虑的问题,如闸启闭机型式选择,淤积以及防腐等方面的问题。     

水利水电工程中的水闸设计问题及其设计分析

水闸在水利水电工程中发挥控制水流量、调节水位的重要作用,其设计质量与水利水电工程质量及其运行安全息息相关,因此,相关设计人员在设计水利水电工程水闸时,必须要充分结合实际情况,详细调查与研究周围环境,严格要求各设计环节,进而保证设计质量及工程质量.本文从水利水电工程水闸分类着手,对水闸设计面对的问题及优化要点进行分析.     

对新疆开都河第三分水枢纽中型水闸除险加固方案的认识

针对目前新疆开孔河流域灌区内实施的大中型水闸除险加固项目,从运行管理角度出发,论述开都河第三分水枢纽工程在除险加固方案论证和设计及具体实施工程中应当注意的问题,指出设计及施工过程中应注意结合运行管理的各项要求,并考虑加固措施对原建筑物的影响.通过多方案对比,优选设计方案,避免对除险加固和工程运行造成影响.为合理实施此类中型水闸除险加固提供参考依据.     

新疆水利工程施工招投标分析

在城乡经济发展中,水利工程应当构成其中的核心与基础。从目前现状来看,水利项目建设通常会涉及到较多的流程与环节,在这其中的招投标应当属于关键。工程招投标是否顺利,直接关系到整个水利项目的质量,同时也决定着后期进行的水利施工。水利工程的有关负责人应当依照现行的招投标流程来完成项目投标与项目招标工作,在此前提下保障水利项目的整体建设质量,进而提升水利项目施工的科学性以及合理性。对于新疆地区的水利工程而言,应当明确工程招投标的基本内容及其重要事项;结合新疆水利工程的建设现状,探求健全施工招投标的可行措施。     

珠江三角洲水资源配置工程全过程造价控制措施

探讨水利工程项目全过程造价管控措施,构建完善的造价控制体系,实现项目预期限额成本目标.以珠江三角洲水资源配置工程为例,阐述了水利工程项目造价存在的主要问题及其造价管理的重要性,给出策划、设计、招标投标、施工及竣工等阶段的造价管控措施体系,实现工程全过程造价管控目的.     

沉管灌注桩围壁在深基开挖中的应用

在一些水利工程如泵站、水闸等的施工实践中,常常会碰到在软基上进行深基开挖所带来的问题,尤其对受场地限制的工程来说,无法进行常规开挖,而必须考虑其它的开挖措施。通过经济技术比较及实践,证明了利用沉管灌注桩围壁进行深基开挖的优越性,并且通过对整个施工过程的观测、试验、总结,为这一技术的进一步应用提供了实践经验。     

微分进化算法在软土水闸桩基优化设计中的应用

修建于深圳西部地区的水闸工程几乎均选址于淤泥层深厚的河涌、滨海滩涂区,导致水闸桩基造价占总造价比重明显高于非软土地区,因此研究该区域水闸桩基优化设计具有较强的现实意义.通过实例分析,基于现行规范要求,建立了微分进化算法的水闸桩基优化模型,分析结果表明该优化模型能快速给出桩基设计各参数的最优化取值组合,达到提高设计效率、节省工程造价的目的.     

基于TRIZ理论的滨海水闸闸下防冲技术研究

滨海水闸设计条件复杂,防冲问题突出,以TRIZ创新理论为基础,通过因果属性分析法,系统地梳理了水闸闸下冲刷中存在的内在规律和原理,探索多方案、多目标的消能防冲办法。结果表明,基于该理论所提出的解决方案多数已为各方学者所采用,TRIZ理论既可为设计提供比选方案,也为防冲技术研究提供了方向,值得进一步引入到水利工程的科研及设计创新中。     

农田水利工程融入BIM技术的探索与实践

针对农田水利工程项目设计内容复杂、老百姓理解困难，施工效率低等问题；目前BIM技术发展迅速，研究通过某一高标准农田项目利用BIM技术进行三维建模实现设计可视化、协同化；使用BIM软件快速的实现单体工程的可视化，直观立体的设计模型增强了参与者对项目的理解能力，同时也大幅度提高设计、施工质量和速度，提高整体项目建设质量。研究围绕着高标准农田建设中的农田水利工程设计展开，在分析农田水利工程特点的基础上，进一步研究运用BIM技术实现高标农田项目可视化、一体化。     

水闸基础类型与地基特性的相关关系

水闸基础的受力计算理论上还存在一些尚未解决的问题,因此,针对水闸基础设计中常见且较难处理的水闸基础类型与地基特性的相关关系,采用链杆法求解弹性地基梁的通用程序,进行了大量计算,通过分析讨论,取得的结果可应用到工程实际中。     

水资源水质水量优化配置分析

本研究旨在实现水资源水质水量的优化配置,通过对水资源水质水量优化配置的生态经济学理论进行分析,指出水资源水质水量优化配置的概念,在内涵分析基础上确定了水资源水质水量优化配置的具体阈值原理和模型体系框架.同时对青海水资源水质水量的优化配置进行分析,指出不同区域的水资源水质水量需要进行针对性的优化配置.     

水资源管理中水量水质联合调控的模式探讨

在水资源管理中,水量水质联合调控主要是为了协调生态环境.利用运筹学、系统方法论、宏观经济学为计算基础,通过控制流域污染物来达到水质控制的目标.基于此,本文对水资源管理中水量水质联合调控的模式进行探讨.     

Sugarcane water use from shallow water tables: implications for improving irrigation water use efficiency

The resource potential of shallow water tables for cropping systems has been investigated using the Australian sugar industry as a case study. Literature concerning shallow water table contributions to sugarcane crops has been summarised, and an assessment of required irrigation for water tables to depths of 2 m investigated using the SWIMv2.1 soil water balance model for three different soils. The study was undertaken because water availability is a major limitation for sugarcane and other crop production systems in Australia and knowledge on how best to incorporate upflow from water tables in irrigation scheduling is limited. Our results showed that for the three soils studied (representing a range of permeabilities as defined by near-saturated hydraulic conductivities), no irrigation would be required for static water tables within 1 m of the soil surface. Irrigation requirements when static water tables exceeded 1 m depth were dependent on the soil type and rooting characteristics (root depth and density). Our results also show that the near-saturated hydraulic conductivities are a better indicator of the ability of water tables below 1 m to supply sufficient upflow as opposed to soil textural classifications. We conclude that there is potential for reductions in irrigation and hence improvements in irrigation water use efficiency in areas where shallow water tables are a low salinity risk: either fresh, or the local hydrology results in net recharge.     

浅析传统水利向环境水利及生态水利的转变

农田水利建设一直是我国农业发展的重中之重,最初的农田一般仅依靠自然河水和雨水进行灌溉,而后由兴修的水利工程进行灌溉,农水建设发展到今天开始重视环境水生态.传统农田水利向环境水生态转变是一种必然的发展趋势.这种形式的转变能够最大限度地满足农业经济发展中的用水需求,而且不会对生态环境带来危害.本文主要分析农田水利发展对环境的影响,并概述了传统农业水利向环境水生态转变的过程.     

水源更换对自来水厂进水泵房给水泵的影响

以杭州市清泰水厂进水泵房给水泵为对象,通过对千岛湖作为第二供应水源后水质变化进行理论分析和试验研究,以及水源变化后水泵实际流量扬程等性能进行分析研究,提出在千岛湖、钱塘江等多水源下给水泵的选型设计。通过给水泵叶轮切削的方式,使给水泵新的工况点处于高效区域内,确保给水泵安全顺利生产运行,提高进水泵房给水泵的效率,满足日供水量的要求。     

Non-conventional water resources and opportunities for water augmentation to achieve food security in water scarce countries

Given current demographic trends and future growth projections, as much as 60% of the global population may suffer water scarcity by the year 2025. The water-use efficiency techniques used with conventional resources have been improved. However, water-scarce countries will have to rely more on the use of non-conventional water resources to partly alleviate water scarcity. Non-conventional water resources are either generated as a product of specialized processes such as desalination or need suitable pre-use treatment and/or appropriate soil–water–crop management strategies when used for irrigation. In water-scarce environments, such water resources are accessed through the desalination of seawater and highly brackish groundwater, the harvesting of rainwater, and the use of marginal-quality water resources for irrigation. The marginal-quality waters used for irrigation consist of wastewater, agricultural drainage water, and groundwater containing different types of salts. In many developing countries, a major part of the wastewater generated by domestic, commercial, and industrial sectors is used for crop production in an untreated or partly treated form. The protection of public health and the environment are the main concerns associated with uncontrolled wastewater irrigation. The use of saline and/or sodic drainage water and groundwater for agriculture is expected to increase. This warrants modifications in the existing soil, irrigation, and crop management practices used, in order to cope with the increases in salinity and sodicity that will occur.     

Effect of soil water osmotic potential on growth and water relationships in barley during soil water depletion

Summary Barley plants (Hordeum distichum, L., cv. Zita) grown in a sandy soil in pots were adjusted during a pretreatment period of 5 days to three levels of soil water osmotic potential by percolating 61 of a nutrient solution with additional 0, 22.3 and 44.6 mM KCl. A drying cycle was then started and the plants were harvested when the soil water matric potential had decreased to –1.4 MPa, respectively 6, 7 and 8 days later.No significant differences in dry matter yields, transpiration coefficients and wilting percentages were found between treatments.During the drying cycle leaf water potential ( _l ) decreased concomitantly with decrease in soil water potential ( _s ) with almost constant and similar differences ( _l – _s ) for all treatments despite differences in levels of potentials. The concomitant decrease in leaf osmotic potential () was due partly to dehydration (58%) and partly to increase in leaf solute content (42%) independent of treatment. The part of total osmotic solutes due to K decreased relatively during the drying cycle.Close relationships were found between and _l as functions of relative water content (RWC). Identical curves for the two levels of salt treatment agree with similar concentrations of K, Cl, and ash found for salt treated plants indicating that maximum uptake of macro nutrients may have been reached.During the main part of the drying cycle the turgor potential as function of RWC was higher and decreased less steeply with decreasing RWC in the salt treated than in the non-salt treated plants.In the beginning of the drying cycle additions of KCI lowered the transpiration rates of the salt treated plants resulting in a slower desiccation of the soil and hence an increased growth period. A delay in uptake from a limited soil water supply may be advantageous during intermittent periods of drought.     

Production and water use in lettuces under variable water supply

The effects of a variable water supply on the water use, growth and yield of two crisphead and one romaine (i.e., Cos) lettuce cultivar were examined in a field experiment using a line source sprinkler system that produced a range of water regimes that occur in growers fields. Four locations at increasing distances from the main line were monitored through the season (i.e., from thinning to harvest, 28–63 days after planting (DAP)). These locations at the end of the season corresponded to: (1) rewatering to field capacity (FC); (2) watering with a volume 13% below that required in the field capacity treatment (0.87*FC); (3) 30% below FC (0.70*FC); and (4) 55% below FC (0.45*FC). A linear production function for dry matter accumulation and fresh weight vs. crop evapotranspiration (ET_c) was determined for lettuce during this period, giving a water use efficiency for dry matter of 1.86 g m^–2 mm^–1 and for fresh weight of 48 g m^–2 mm^–1 . For lettuce irrigated to field capacity, ET_c between thinning and harvest was 146 mm; maximum crop coefficients of 0.81–1.02 were obtained at maturity (55–63 DAP). For the three irrigation treatments receiving the largest water application, ET_c was higher in the Cos culivar than in the two crisphead lettuce cultivars which had similar ET_c. Plant fresh weight was more sensitive than dry weight to reduction in water supply. In the FC treatment, root length density and soil water extraction were greatest in the top 0–45 cm, and decreased rapidly below 45 cm depth. Soil water extraction by roots increased at lower depths when irrigation was reduced. Instantaneous rates of leaf photosynthesis and leaf water potential showed no response to the irrigation treatments in this study, despite differences in biomass production. Evaporation was determined to be the major component of ET_c for 45 of the 63 days of the growing season. The large loss of water by evaporation during mid-season and the apparent insensitivity of lettuce to the volume of irrigation during this period may provide an opportunity for reducing irrigation applications.     

Drainage water reuse

Saline-sodic (4 < EC[dS/m] < 30; 10 相似文献