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431.
新疆克孜尔水库地震风险分析及防范研究 总被引:2,自引:0,他引:2
克孜尔水库地震风险防范系统是在强震台阵、F2活动断层监测设备完善、观测分析中心及抗震风险防范中心等硬件建设的基础上,通过在GIS平台上建立构造纲要、潜在震源区、峰值加速度区划、大坝所在位置等专题图层,完善地震传输系统、大坝数字减灾系统等软件建设.把强震监测信息系统技术应用于水库地震风险防范决策支持和实际运行科学管理, 实现可在线处理子台传输过来的地震加速度时程曲线.分析各测点场地最大加速度值、水工结构的动力放大系数、场地卓越频率、结构自振频率、地震持续时间及水库诱发地震判别等重要参数,为各项决策提供可靠的快速支持,从而建立国内首座在活动断层上直接建坝的克孜尔水库大坝的震后快速报警体系和初步数字减灾系统,形成有效的震后快速修复措施, 为深入开展活动断层上筑坝技术研究奠定基础. 相似文献
432.
尾矿库安全评价中的科学问题及评价方法探讨 总被引:9,自引:5,他引:9
尾矿库的安全稳定在矿山的安全生产和环境保护中具有十分重要的意义。尾矿库安全评价应该研究坝及其附属构筑物的安全状况,评价尾矿库的安全等级。本文立足于尾矿库工程的实践经验,探讨了尾矿库安全评价中应该涉及的科学问题,并对其相应的评价方法进行了探讨,指出了尾矿库安全评价应该采用的基于有限元理论的定量评价方法。本文认为排水不良和地震液化是影响尾矿坝稳定性的重要因素,应该在评价过程中给予重点的关注和研究。此外,在尾矿库的安全评价中,应更多地采用有限元数值计算方法研究上述科学问题。 相似文献
433.
三峡库区滑坡稳定性评价研究 总被引:4,自引:3,他引:4
三峡水库蓄水后,库水位将在145~175 m范围内波动,动水压力和水的软化作用是滑坡失稳的主要因素.库区滑坡稳定性评价规范要求采用不平衡推力法,但在考虑库水位下降产生的渗透力时,对渗流浸润线的确定缺乏理论依据,更没有实测数据的支持.为此,笔者运用一维的布辛内斯克方程,研究三峡水库蓄水后库水位下降和暴雨作用下滑坡渗流浸润线的变化规律;建立了渗流作用下滑坡稳定性评价模型;分析降速、渗透系数、暴雨等对滑坡稳定性的影响. 相似文献
434.
为合理评价库岸涉水滑坡危险性,基于层次分析法与模糊理论,构建滑坡危险性现状评价模型,并利用优化支持向量机构建滑坡变形预测模型,通过对比分析实现滑坡危险性综合判断.结果表明:大柿树滑坡危险性现状为69.78分,风险等级为Ⅲ级,属高度危险;通过危险性预测评价,滑坡变形呈持续增加趋势,将趋于不利方向发展;综合滑坡危险性现状分... 相似文献
435.
436.
Tom Myers 《Journal of the American Water Resources Association》2013,49(5):1213-1224
As demand for water in the southwestern United States increases and climate change potentially decreases the natural flows in the Colorado River system, there will be increased need to optimize the water supply. Lake Powell is a large reservoir with potentially high loss rates to bank storage and evaporation. Bank storage is estimated as a residual in the reservoir water balance. Estimates of local inflow contribute uncertainty to estimates of bank storage. Regression analyses of local inflow with gaged tributaries have improved the estimate of local inflow. Using a stochastic estimate of local inflow based on the standard error of the regression estimator and of gross evaporation based on observed variability at Lake Mead, a reservoir water balance was used to estimate that more than 14.8 billion cubic meters (Gm3) has been stored in the banks, with a 90% probability that the value is actually between 11.8 and 18.5 Gm3. Groundwater models developed by others, observed groundwater levels, and simple transmissivity calculations confirm these bank storage estimates. Assuming a constant bank storage fraction for simulations of the future may cause managers to underestimate the actual losses from the reservoir. Updated management regimes which account more accurately for bank storage and evaporation could save water that will otherwise be lost to the banks or evaporation. 相似文献
437.
水淹和水窜是油田在水驱开发时常见的安全问题,储层非均质性是引起水淹和水窜的主要原因之一。为研究储层非均质性对于水淹水窜的作用,通过层次聚类分析法建立储层非均质综合指数关系式,并将其转化为水淹水窜风险概率,把水淹水窜风险概率进行分级,以此判断非均质性对于水淹水窜的作用。以BD油田阜二段第三砂层组为例进行水淹水窜风险评估,结果表明:研究区非均质性严重,水淹水窜风险概率均大于80%,储层非均性极容易导致油田在注水开发时发生水淹水窜。该区在注水开发时需要重视工艺设计与防护措施,以降低水淹水窜风险。 相似文献
438.
439.
ABSTRACT: Hyalite Reservoir, Montana, was studied to determine properties of this small, montane, headwater, deep-release reservoir relative to reservoirs at lower elevations. While retention times for waters were as brief as 12 d, the mean residency of 40 d from mid-March to mid-December was within the range reported for other reservoirs. No significant through-reservoir gradients for suspended sediments were observed, contrasting to observations for most reservoirs. Thermal stratification, evident during the first part of the summer, was disrupted in August by cool, dense tributary inflows and strong wind-induced mixing. Dissolved oxygen concentrations paralleled temperature patterns in the reservoir; lowest average values for both occurred in waters sampled nearest the outlet. Total phosphorus averaged greater than twice the total nitrogen concentrations; greatest average concentrations for both were found in the near-bottom waters nearest the outlet. Enrichment of nitrogen concentrations in outflow over inflow waters is hypothesized to occur through nitrogen fixation by Aphanizonwnon flos-aquae. Despite the relatively high quality of waters from tributary inflows, an algal bloom, chlorophyll a concentrations, and primary productivity estimates suggested that the reservoir was mesotrophic. Circulation of waters within the reservoir was primarily influenced by wind-induced mixing, thermal gradients, and currents produced by the deep-water outlet. 相似文献
440.
Ching‐pin Tung Shao‐yiu Hsu Chia‐Ming Liu Jr‐Shin Li 《Journal of the American Water Resources Association》2003,39(3):649-657
ABSTRACT: A procedure to apply genetic algorithm to optimize operation rules is proposed and applied to the LiYuTan Reservoir in Taiwan. The designed operation rules are operation zones with discount rates of water supply. The first step of the procedure is to predefine the shape of boundary curves of operation zones according to reservoir storage routing. Then, relatively fewer variables are used to describe the curves, and a last genetic algorithm (GA) is applied to optimize the curves. The procedure is applied to the newly built LiYuTan Reservoir for increasing domestic water demands. Shortage index is used to evaluate the performance of operation zones. A year is divided into 36 operational periods, with each month containing three operational periods. The shortage indexes calculated in operational periods are 9.81, 8.27, and 7.13, respectively, for the reservoir without operation rules, applying operation zones optimized by GA with encoding 36 storage levels for each curve, and adopting operation zones optimized by GA with encoding the curves with predefined shape. The average deficits for the three cases are 77.2, 43.6, and 33.3 (104 m3/day), respectively. The results indicate that operation zones optimized by the proposed procedure have smaller shortage indexes and lower average deficits. In addition, the optimized operation zones have less variation and thus are more practical for operation. Conclusively, the proposed procedure utilizing GA to optimize operation zones with predefined shape can provide better and realistic outcomes through limited iterations. 相似文献