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51.
地电场作用下矿层中气体渗流特性的实验研究 总被引:1,自引:0,他引:1
针对地球物理场中地电场对原地浸出过程中气体渗流特性的影响,在实验室采用三轴渗流实验装置和电场实施装置,研究了外加电场作用下矿层中气体的渗流特性。实验结果表明:地电场对矿体中气体渗流特性的影响非常明显;加正向电场后,气体渗流速度比无电场时要大,反向电场作用下,气体渗流速度比无电场时要小,并且渗流速度随气体压力梯度增大成线性增加,矿层中气体渗流量随电场强度升高成线性增大;渗透性越好的矿层,地电场作用下气体的地电场电动效应越明显;地电场作用时,矿层的等效渗透系数可表达成ke=k(1 βE)。 相似文献
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The finite-element method provides a convenient and effective means for solving problems of seepage in unsaturated soils. However, convergence difficulties exist in numerical simulations of unsaturated flow analyses because of the high nonlinearity of the soil hydraulic properties. This technical note presents a combination approach consisting of a rational function transformation method and a common under-relaxation technique to solve the h-based form of Richards equation. Numerical studies show that this combined method can use a larger time step and corresponding oscillation-free mesh size to produce acceptable results and also converge to a stable solution quickly in each time step. 相似文献
54.
矿渣砖具有强度大、抗冻融性强、生产工艺简单、价格低、与水泥粘接性强的特点,是渠道防渗及各类水工建筑中可广泛应用的新型建筑材料。本文介绍了矿渣砖防渗渠道的试验运用及观测分析情况。 相似文献
55.
Osama K. Nusier Ahmed Alawneh Abdallah I. Malkawi 《Bulletin of Engineering Geology and the Environment》2002,61(2):145-152
The Kafrein dam, 480 m long and 30 m high, is located on the Wadi Kafrein, a few kilometres from the active Jordan Valley
fault. The Jordan Valley Authority proposed raising the crest of the existing dam by approximately 7 m and extending the length
of the embankment to 554 m, in order to increase its storage capacity by 6 million m3 to a total of 8.5 million m3. The paper discusses the likelihood that existing seepage problems will be exacerbated when the dam is raised and proposes
some remedial actions to increase the safety of the dam and minimise both the amount of seepage and any adverse effects.
Electronic Publication 相似文献
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The right wing embankment of the headrace channel of a hydropower plant, failed adjacent to the concrete intake structure. The failure also caused damages of the penstocks and flooding of the powerhouse. 相似文献
58.
根据达西定律 ,建立了风化矿体渗流的数值模型 ,并采用有限元方法求解。 1 8个矿体渗流计算模型分别考虑了不同注入形式、注入压力、矿岩渗透性、贮水系数对浸出的影响。通过计算分析 ,确定了原地浸出的钻孔布置参数、布液强度、作业制度及可能的渗漏情况。 相似文献
59.
Seepage through embankment fill materials is crucial issue in the construction of embankments for irrigation and drainage projects. Proper ground improvement methods should be used to improve the strength and stability characteristics of soil used as fill material. Utilization of waste plastic materials to enhance the engineering properties of soil is a sustainable approach. Additionally, the use of raw products directly from plastic recycling units in the form of flakes and pellets as soil additives has the potential to further enhance the economic benefits of this method. This study randomly mixed plastic materials with soil for use in the construction of earth embankments, such as river levees, dykes, and canal diversion structures, and evaluated the effectiveness of these materials in reducing seepage failures in hydraulic structures. To achieve these goals, this study collected high-density polyethylene (HDPE) plastic from plastic recycling units and used soil mixed with HDPE plastic in the form of flakes and pellets in different contents as embankment fill materials, then evaluated how these materials affected the piping features. Laboratory experiments were conducted to determine the seepage velocity and critical hydraulic gradient of soil mixed with plastics in various contents and to compare the values with those of plain soil. The results showed that random distribution of waste plastics in the form of flakes and pellets in soil is an effective method for improving the piping resistance of soil. 相似文献
60.
M. Nicksiar M. Esfandiary A. Mehinrad K. Binazadeh 《International Journal of Rock Mechanics and Mining Sciences》2007,44(7):1035-1044
Bakhtyari Dam and Hydropower Plant Project is one of the largest hydroelectric projects in Iran. This dam is located in Lorestan, in southern Iran, on the Bakhtyari river, which is a headstream of the Dez River. Previous gallery surveying showed that some open joints were present in the abutments. These joints may act as a good conduit for seepage. Five galleries were used to carry out seismic tomography in the right and left abutments (GR1, GR2 and GR3, GL2–GL3, totally 765 m). The objective of the tomography was to detect these weak zones susceptible for seepage. Velocity images obtained by P-wave travel time tomography indicated that in the level of GR2 gallery upward there is a large zone of low velocity. But the rock mass quality seems better in the left abutment. In spite of unfavorable condition in R23 block (GR2–GR3), the P-wave velocity between GR2 and GR1 galleries is in the range of undisturbed limestone. Despite the presence of these weak zones, the placement of the dam is where the rock mass quality is good, and the design of the grout curtain could help to bypass the reservoir water away from these seepage paths. 相似文献