A method for coupled arch dam‐foundation‐reservoir seismic behaviour analysis     

R. J. Cmara 《地震工程与结构动力学》2000,29(4):441-460

This paper presents a method for coupled arch dam–foundation–reservoir seismic behaviour analysis. The dam is discretized by finite elements (FE) and the foundation and reservoir are discretized by boundary elements (BE). The opening of contraction joints and the spatial variability of the seismic action is taken into account. The study of Pacoima dam by this method is also presented. The computed results show that no cracks were to be expected due to the vibrations induced during the Feb. 9, 1971 San Fernando earthquake. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

Predicting dam-related downstream geomorphic response with widely available stream gauge data: A case study of the Godavari River Basin,India     

Joy Sanyal  Priyanka Dasgupta  Shinjiro Kanae 《Singapore journal of tropical geography》2020,41(2):284-298

Dam-related downstream adjustments of riverbeds are normally investigated by analysing the trend in sediment supply and high flow events during the pre- and post-dam periods. The required data for existing predictive models is not measured at river gauges, which limits the application of these tools. We derived the frequency of sediment-transporting streamflow events (T*) and upstream sediment supply (S*) in the pre- and post-dam periods with widely available gauged records and predicted changes in the downstream riverbed by adapting an existing model. Ten gauging stations in the Godavari River Basin, India, located downstream of dams, were chosen as study sites. Annually surveyed cross-sections at each site validated the accuracy of the predicted dam-related downstream changes. Then, a regression equation (R² = 0.75) was established between T*/S* (independent variable) and changes in the downstream bed elevation (dependent variable) for the Godavari Basin. We recommended that similar local empirical equations be formulated for larger river basins. Models of large-scale rainfall-runoff and sediment transport processes that can account for the influence of dams, such as the Soil & Water Assessment Tool, can be paired with the proposed regression equation to estimate dam-related downstream erosion and deposition with globally available data.  相似文献   

RESPONSE OF EARTH DAMS TO P AND SV WAVES USING COUPLED FE-BE FORMULATION     

H. ABOUSEEDA  P. DAKOULAS 《地震工程与结构动力学》1996,25(11):1177-1194

A study of the effects of dam–foundation interaction on the response of earth dams to obliquely incident P and SV waves is presented. Emphasis is placed on the effects of the foundation flexibility and the spatial variability of the ground motion. The study is based on a rigorous hybrid numerical formulation that combines the efficiency and versatility of the Finite Element Method (FEM) and the ability of Boundary Element Method (BEM) to account for the radiation conditions at the far field. The developed hybrid method is very powerful and can be used efficiently to obtain accurate solutions of problems of complex geometry, material heterogeneity and, for time-domain analyses, material nonlinearity. The 2-D frequency-domain formulation is used here to investigate the response of infinitely long earth dams to obliquely incident P and SV waves. By accounting rigorously for the energy radiated back into the half-space, the study demonstrates the dramatic effect of the flexibility of the foundation rock in reducing the overall response of the dam. The effects of the spatial variability of the ground motion for P and SV waves travelling across the width of the dam are also important, but somewhat less pronounced than those of the foundation flexibility.  相似文献   

快速筑堤技术——鲎式轻质堤坝的结构和筑堤方法     

陶松垒  傅晓航 《海洋学研究》2006,24(Z1):83-90

针对软基堤坝稳定性差,容易沉陷滑移,土石方堆不上,工期长,无法快速施工等问题,提出了鲎式轻质堤坝结构和筑堤方法,又称"松垒筑堤法".它减轻了易沉陷部位的质量,均衡堤坝荷重,增强整体稳定性,提高强度,使堤坝与地基溶为一体,消除了堤坝的不均匀沉降;是一种在软弱地基上应用仿生结构的筑堤方法.  相似文献   

Lacustrine transgressions in the late Cenozoic Ussuri-Khanka depression (Primor’e)     

A. M. Korotkii  T. A. Grebennikova  L. P. Karaulova  N. I. Belyanina 《Russian Journal of Pacific Geology》2007,1(4):352-365

In the Ussuri-Khanka depression of Primorye, the Quaternary alluvial-lacustrine and lacustrine sedimentogenesis progressed under conditions of transgressive accumulation in response to the depression tectonic subsidence and recurrent climatic fluctuations. The alluvial dams and irregular accumulation are proved to have been the leading factors of lakes’ formation within the depression. As is shown, fluctuations of the water level in limnic reservoirs depended on the climatic changes. New data considered in this work confirm the lacustrine genesis of a greater part of the Middle Pleistocene-Holocene sedimentary succession in the Khanka depression. Two transgressive phases, when the water level in the lakes rose by 1.5–2.0 m above the present one, are established for the Subboreal. The general conclusion is that the mesorhythmic structure of the sedimentary succession in the Ussuri-Khanka depression reflects the influence of climatic fluctuations in the Late Cenozoic.  相似文献   

Flood hydrograph attenuation induced by a reservoir system: analysis with a distributed rainfall‐runoff model     

Nicola Montaldo  Marco Mancini  Renzo Rosso 《水文研究》2004,18(3):545-563

Spatially distributed hydrologic models can be effectively utilized for flood event simulation over basins where a complex system of reservoirs affecting the natural flow regime is present. Flood peak attenuation through mountain reservoirs can, in fact, mitigate the impact of major floods in flood‐prone areas of the lower river valley. Assessment of this effect for a complex reservoir system is performed with a spatially distributed hydrologic model where the surface runoff formation and the hydraulic routing through each reservoir and the river system are performed at a fine spatial and time resolution. The Toce River basin is presented as a case study, because of the presence of 14 active hydroelectric dams that affect the natural flow regime. A recent extreme flood event is simulated using a multi‐realization kriging method for modelling the spatial distribution of rainfall. A sensitivity analysis of the key elements of the distributed hydrologic model is also performed. The flood hydrograph attenuation is assessed. Several possible reservoir storage conditions are used to characterize the initial condition of each reservoir. The results demonstrate how a distributed hydrologic model can contribute to defining strategies for reservoir management in flood mitigation. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

地电影像技术在水利堤坝隐患探测中的应用     

魏月红  刘晓芳  崔元星 《煤田地质与勘探》2002,30(2):60-61

阐述了最新发展起来的物探方法——地电影像技术的原理及其应用在水利堤坝隐患探测中的地质—地球物理基础,并结合实例讨论了该领域的应用前景   相似文献   

Improvement of SWAT2000 modelling to assess the impact of dams and sluices on streamflow in the Huai River basin of China     

Gangsheng Wang  Jun Xia 《水文研究》2010,24(11):1455-1471

Hydrological simulation and assessment in a dam–sluice regulated river basin are a complex and challenging issue. In this article, an improved SWAT2000 modelling system was developed that incorporated the Shuffled complex evolution (SCE‐UA) optimization algorithm and the multi‐site and multi‐objective calibration strategy. The implication of multi‐objective is different for different types of outlets, i.e. streamflow for an ordinary outlet, inflow for a sluice, and water storage for a reservoir. Model parameters were redefined to improve model simulations. The surface runoff lag time (SURLAG) was extended as a spatially distributed parameter, and a correction coefficient was introduced to modify the saturated hydraulic conductivity. The modelling system was then applied to the Huai River basin of China under various climatic conditions, including a very dry year (1999), a dry year (1981), an average year (1971), and wet year (1991). In all, 26 dams and 35 sluices were considered, among which about 20 dams/sluices were used for model calibration. The impact assessment primarily focused on the very dry year (1999). The results indicated that the released water from large reservoirs was blocked in the river channels by sluices located downstream. In the very dry year, the dam–sluice operations could result in an increase of the runoff volume during the non‐flood season and a decrease in runoff during the flood season, but the changing magnitude during the non‐flood season was much greater. An important conclusion of this case study is that the sluices in the Sha‐Yin branch located in the north region and the dams in the southern mountainous region above the Wangjiaba Hydrological Station have played the most significant role in regulating the streamflow of the entire river basin. The methods addressed in this article can simulate hydrological regime in the river basins regulated by dams and sluices under different climatic conditions at the whole‐watershed scale. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Changes in hydrology and sediment delivery of the Mekong River in the last 50 years: connection to damming,monsoon, and ENSO   总被引：1，自引：0，他引：1  

Zuo Xue  J. Paul Liu  Qian Ge 《地球表面变化过程与地形》2011,36(3):296-308

As the population and economy boom, more and more dams are being built in the Mekong River basin. Previous studies have revealed that Manwan Dam had little influence on the runoff–SSC (suspended sediment concentration) relationship, and the sediment load was relatively stable over the past 40 years. However, little is known at present on the relationship among monsoons, El Niño Southern Oscillation (ENSO), precipitation, runoff, and the impact of dams on the delta dynamics. A comprehensive hydropower GIS database covering the entire Mekong basin is presented in this study. Mann–Kendall trend analysis showed no significant change in precipitation and runoff over the past 50 years. Spectral analysis showed that the runoffs of the middle to lower reach of Mekong River are correlated with the Indian Monsoon, where as the East Asian Monsoon's influence is mainly on the lower reach. With another 200 new dams to be added to the basin in the next couple of decades, changes are expected in both hydrological regime and delta dynamics. On one hand, the runoff showed a closer connection with the regional precipitation and ENSO in the post‐dam period (1993–2005) than in the pre‐dam period (1950–1993). Such a relationship is expected to be even closer when more dams are completed. On the other hand, both daily maximum and minimum water levels on the delta plain have shown an abrupt drop since the end of 1994. This reduced water‐level gradient between the river and sea inevitably weakens the sediment discharge to the coast, which might intensify the ongoing coastal erosion on the eastern part of the delta plain. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

高坝工程总溶解气体过饱和与水体含沙量关系     

曲璐 《水科学进展》2011,22(6):839-843

为研究伴随高坝泄水产生的总溶解气体(TDG)过饱和现象与水体中含沙量关系的问题,提出切实可行的减缓TDG过饱和影响的措施,通过实验的方法,对含沙水体中TDG过饱和的生成和释放进行了研究分析。结果表明:同样初始条件下,在含沙水体与清水中的TDG过饱和生成过程中,TDG过饱和度没有明显变化。在TDG释放过程中,含沙水体中TDG释放速率明显快于清水中TDG释放速率,据此提出可通过开启排沙孔等泄洪调度方式使泄流中悬沙含量增加,促使TDG沿程释放加快,降低其对鱼类的影响。  相似文献