共查询到20条相似文献,搜索用时 55 毫秒
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针对该电站坝区岩体层间层内错动带原位渗透特性研究,提供了相应渗透特性指标,为大坝防渗轮廓设计指标提供依据。 相似文献
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层间层内错动带对溪洛渡高拱坝坝肩(基)稳定性的影响研究 总被引:1,自引:0,他引:1
在细致模拟溪洛渡高拱坝坝址区层间层内错动带空间展布和连通特征的基础上,采用三维非线性有限单元法,定量分析了层间层内错动带的变形和超载破坏规律,重点对比分析了不同高程层间错动带的相对变形,评价其对坝体稳定性的影响。结果表明,在高高程的层间错动带如C9、C8等,其下层面向下游的位移略大于上层面向下游的位移;而建基面以下的C3、C2、C1由于上表面受坝基推力作用更大,致使下层面向下游的位移小于上层面向下游的位移。左右岸均存在一个相对位移的转捩高程(约在G5 390m高程左右),在该高程上的层间错动带的相对变形接近于零。坝基下部层间错动带C3对坝踵变形和稳定性影响最为显著。 相似文献
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《人民黄河》2021,(5)
白鹤滩水电站左岸拱坝坝基边坡地质条件复杂,坝基边坡内发育的缓倾坡外的层内错动带、反倾坡内的断层和柱状节理玄武岩是开挖边坡变形响应的重要影响因素。在分析现场监测数据基础上,对白鹤滩左岸拱坝坝基630 m高程以上的剪切变形特征及机理进行了分析研究,采用离散元程序UDEC再现了层内错动带LS_(3319)的剪切变形特征,并对左岸拱坝坝基630 m高程以下的开挖响应特征进行了预测。结果表明:630 m高程以上坝基开挖过程中顺坡向缓倾层内错动带LS_(3319)在开挖面坡脚部位出露前后,对坡脚局部应力场产生较明显的影响,其上下盘岩体表现出不同的变形特征,错动带上盘部分岩体首先出现应力增大或集中现象,随着开挖面下移直至错动带出露,出现开挖卸荷引起的岩体松弛;630 m高程以下受层内错动带LS_(331)影响产生剪切变形,上盘浅层岩体出现卸荷松弛。错动带剪切变形主要发生在错动带的坝基面开挖揭露过程中,变形量值主要受赋存地应力条件、结构面参数和产状等因素控制。 相似文献
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溪洛渡水电站拱坝设计 总被引:1,自引:1,他引:0
通过对溪洛渡混凝土双曲拱坝坝体应力分析,基础变模值的改变和坝身开孔等对坝体应力影响分析以及就坝基玄武岩发育的层间层内错动带进行坝肩大块体,小块全和阶梯状滑块的稳定分析,并应用三维非线性整体稳定分析计算,综合评价了溪洛渡拱坝设计的合理性。 相似文献
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玄武岩中石英绿帘石型层内错动带成因初探 总被引:2,自引:0,他引:2
在我国西南地区许多水电站坝区岩体中,缓倾角的层内错动带发育相当普遍,它们对岩体的局部稳定性起控制作用。在某玄武岩坝址区,发育有几种类型的层内错动带,本文对其中的石英绿帘石型层内错动带的成因进行了初步探讨。 相似文献
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河道通过三合泥铺底、浆砌块石护面防渗后,止漏效果显著,促进了河道堤防的稳定,河道崩溃事故大大减少,提高了河道水的利用率,使工程效益得到了较好的发挥。 相似文献
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Dispersion and transport of mass in a fracture network is a percolation process. Macro-scale dispersion is related to travel time, distance, mass distribution and fracture geometry. This article presents a stochastic, discrete fracture model in conjunction with percolation theory to investigate the dispersion phenomenon and the power law relationship between mean square travel paths displacement r2 and particle travel time t. For imposed boundary conditions, particle dispersion is simulated to observe percolation thresholds and dispersion trends in different network structures. Simulation results demonstrate that the critical exponent values of t in the percolated networks are extremely close to the theoretical value of 1.27 and occur at certain percolation factors. Below these percolation factors, the exponents of t increase with decreasing percolation factors, above these percolation factors, exponents decrease with increasing percolation factors. In our simulated cases, the proportionality between r2 and time t is given by t raised to a power between 1.27 and 1.66, depending on the fracture pattern. The coefficient of anisotropic dispersion tensor increases with increasing distance. The percolation process is related to travel time and distance, and cannot be interpreted as a Fickian diffusive process. 相似文献
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通过黄河堤防渗漏模型试验,对分布式光纤传感技术在堤防渗漏监测领域的应用进行了研究,提出了分布式光纤的布设方式,获得了渗漏流量与土体温度变化的关系曲线,据此曲线分析可得出如下结论:当渗漏流量为100 cm3/s时,水的渗透力度较小,渗漏没有影响到土体的温度;当渗漏流量为130 cm3/s时,渗漏通道周围温度明显下降;当渗漏流量为250 cm3/s时,土体有不同程度的塌陷出现。 相似文献
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R. C. Srivastava H. C. Verma B. K. Nanda S. Mohanty 《Water Resources Management》2007,21(11):1955-1972
Percolation tanks are widely used for increasing recharge of ground water resources. This has been used from centuries in
arid and semi arid regions of India and is known by different indigenous name, viz. rapat, nadi etc. However not much work has been done on standardization of the design parameters of these tanks, and therefore most of
the time, tanks are either over designed or under designed. The design parameters of the percolation tank and amount of water
recharged to groundwater during different months depend upon area of catchment, hydrological cover complex characteristics
of the catchment, rainfall characteristics of the area, evaporation loss and seepage rate of the tank bed. Since rainfall
and evaporation are stochastic variables, their distribution should also be accounted for. Further the dimensions of the tank
will vary with the level of probability of design. With this in view, a software has been developed for giving the design
parameters of the percolation tank. The input data are long term daily rainfall and evaporation data, seepage rate of the
tank bed which is a function of textural characteristics and hydraulic conductivity, area of catchment, hydrological complex
characteristics defined by curve numbers, area available for construction of the tank (length and width) for excavated type
of the percolation tank or width of the gully and slope of the drainage way for impounded type of the tank, and cost of the
earthwork for different depths and lead. The output is capacity of the tank for most economic recharge per unit investment,
total recharge during the year, recharge during monsoon and recharge during post monsoon months and expected storage level
at the end of the monsoon. 相似文献
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悬浮液调剖剂在油层中渗滤特征研究 总被引:1,自引:0,他引:1
论文根据质量守恒建立了固相颗粒运移和沉淀动态方程,通过求解得到悬浮液浓度分布和颗粒滞留量分布关系,研究结果表明,颗粒型调剖剂的沿程浓度逐渐降低,随注入时间增加,同一位置上的调剖剂浓度逐渐升高,多孔介质对固相颗粒的渗滤作用,颗粒滞留主要集中在近井周围。岩石渗透率时变动态模型表明,岩石渗透率比其孔隙度的变化幅度大得多,颗粒型堵剂其少量的滞留即可改变岩石渗透率。相同注入量条件下,随注入速度增加悬浮液浓度增加,同时渗透率降低程度增加,提高注入速度有利于将颗粒挤入到多孔介质较深部位。调剖过程中的注入压力动态主要取决调剖地层系数,随注入速度增加,注入压力逐渐回升,但不同注入速度下注入压力的回升速度不同,对于较高的注入压力,调剖剂很容易提前启动中低渗透层,因此注入速度的选择应在注入设备工作条件下,以油层破裂压力为限制,保证注入压力缓速回升。 相似文献
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临沂城引水工程以天然河道为供水水源 ,以 12 0 0mm预应力钢筋混凝土预制管为输水管道 .为解决汛期水质泥沙含量大 ,易造成输水管道淤积等问题 ,采用了埋设于河床砂层的钢筋混凝土渗管为进口取水建筑物 ,引取河床渗透水 ,经过两年多来的运行 ,日供水量满足 8.2万m3要求 ,供水水质色度小于 15度 ,浑浊度小于 5度 ,无肉眼可见物 ,无嗅无味 .该工程措施施工简单、造价低廉、效果良好 . 相似文献