稳定渗流作用下边坡渗出层的水力梯度研究

发布时间：2018-01-08 03:32

本文关键词：稳定渗流作用下边坡渗出层的水力梯度研究　出处：《江西理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：在矿山原地浸矿或其他岩土体渗流中,水力梯度在距出渗口较近的区域呈现非线性变化的边界效应,把这个区域定义为渗出层。渗流破坏首先开始于渗出层,渗出层是岩土体渗流的门户,渗流控制措施的最终目的是保证渗出层不遭受渗流破坏,渗出层的水力梯度变化规律既是渗流计算的关键问题,也是牵引式滑坡的重要影响因素。但是,现如今在边坡稳定性的研究中关于渗出层这一部分不多,对岩土体渗流破坏发生的区域、类型和演变过程也缺少相应的理论,导致相关设计规范如离子型稀土矿原地浸矿中缺乏明确的规定,仅靠经验开挖导流孔或巷道等进行母液的回收,直接影响了矿山的开采效率与安全运行。鉴于此,本文将系统地探讨离子型稀土矿渗出层的水力梯度变化规律以及渗透破坏特性,主要研究内容和结论包括:(1)查找阅读关于原地浸矿的开采技术、渗流规律、渗流破坏模式及机理、边坡稳定性研究内容、边坡防治相关专著论文及科学技术文献,并进行归纳和总结。(2)通过室内横向柱浸渗流试验,研究平均水力梯度与渗出层厚度的关系。试验结果表明,入渗端与出渗端均存在水头损失的边界效应,入渗水头越大边界效应越明显,且出渗一侧的边界效应更加明显,在试样后半部分随着离出渗端的距离越近水力梯度越大且呈非线性变化。土柱的入渗水头越大即平均水力梯度越大,土柱的渗出层厚度越大;土样的孔隙比越小,渗出层的厚度也越大。渗出层内同一个过水断面处竖直方向的流速越来越大,且离出渗端越近,流速差越大。土样的平均水力梯度能反映起始水力梯度,而起始水力梯度对渗出层平均水力梯度的影响很小,所以在渗出层内流速与水力梯度满足线性关系。(3)以室内浸矿柱渗流试验和理论分析为基础,开展离子型稀土矿的室内砂槽模型渗流试验,观察测压管,得到其渗流规律,探讨坡角、上游水位等因素对边坡渗流规律的影响。试验结果表明,随着入渗水头的增高,试样的渗出层厚度增大。在入渗水头高度从70cm到90cm下,当坡角为45°时,渗出层厚度从93cm增长到153cm;当坡角为60°时,渗出层厚度从130cm增长到175cm。坡角越大,渗出层的厚度越大。渗出层内不同水平位置的水力梯度不同,在同一过水断面处随着水平位置的升高水力梯度减小。从入渗端至出渗端处渗透流速越来越大,渗出层内存在同一个过水断面处竖直方向的流速分量越来越大的现象,且离出渗端越近,竖直方向的流速差越大。非渗出层的渗流为达西流,而渗出层的渗流为非达西流。
[Abstract]:In situ leaching mining or other rock mass seepage, boundary effect of regional hydraulic gradient in the distance closer to the seepage of non-linear change, the region is defined as leakage layer. The seepage failure begins from seeping layer, seepage of rock and soil layer is from portal, ultimate goal is to ensure that the seepage control measures from the superficial layer of seepage computation of hydraulic gradient variation of seepage is exudation layer, is also an important factor of retrogressive landslide. However, nowadays in the research of slope stability on the superficial layer of this part is not much, the rock mass seepage failure area, types and evolution also the lack of corresponding theory, leading to relevant design specifications such as in situ ion type rare earth ore leaching in the lack of clear rules, relying on the experience of the excavation of diversion hole or recovery roadway of liquor, has a direct impact on mine The efficiency and safety of mining operation of the mountain. In view of this, this paper will systematically explore the variation of hydraulic gradient ion type rare earth ore layer and exudation of seepage characteristics, the main contents and conclusions are as follows: (1) find reading about in situ leaching mining technology, the rule of seepage and seepage failure mode and mechanism, research content of slope the stability of slope prevention related monograph and literature of science and technology, sum up and summarize. (2) through the indoor seepage test of horizontal column leaching, study on the relationship between the average hydraulic gradient and the exudation of layer thickness. The test results show that infiltration and infiltration end boundary effects are end head loss, the more infiltration head boundary effect is more obvious, and the effect of seepage on one side of the boundary is more obvious in the second half with out of sample permeability end close hydraulic gradient bigger and a nonlinear change. Soil column infiltration head the greater The average hydraulic gradient is bigger, the thickness of the layer of soil column exudation; soil void ratio, exudation layer thickness is greater. Exudation layer with the cross section at a vertical velocity increasing, and from the end of infiltration closer, the greater the difference of average velocity. Hydraulic ladder soil can reflect the degree of initial hydraulic gradient, but has little influence on the initial hydraulic gradient exudation layer average hydraulic gradient, so the exudation layer velocity satisfies the linear relationship with the hydraulic gradient. (3) to the indoor seepage test and leaching pillar theory, sand tank model to carry out ion seepage test rare earth mine, observe the piezometric tube, the seepage of slope angle and the effect of upstream water level and other factors on the slope seepage law. The experimental results show that with the increase of infiltration head, the thickness of specimen increases. In the superficial layer of infiltration head height from 70cm to 90cm, when the slope angle 45 degrees, exudation layer thickness increases from 93cm to 153cm; when the slope angle is 60 degrees, exudation layer thickness increases from 130cm to 175cm. the greater slope angle, exudation layer thickness is greater. Hydraulic gradient in different horizontal positions within the superficial layer of different, in the same cross section along with high hydraulic lift the horizontal position of the gradient decreases. From the end to the infiltration leakage end of seepage velocity increasing, superficial layer of memory in the same cross section at the vertical velocity component is more and more big phenomenon, and from the end of infiltration closer, the vertical velocity difference is large. The seepage nonexudative layer for Darcy flow, seepage and exudation layer for non Darcy flow.

【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU43

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