寻乌离子型稀土矿体边坡稳定性研究

发布时间：2018-06-04 00:15

本文选题：水压率 + 水土统一算法　；参考：《江西理工大学》2017年硕士论文

【摘要】：江西寻乌县的离子型稀土矿体为属于粉土,是介于砂性土和黏性土之间的一种过渡性土,研究该类矿体的抗剪强度计算方法,对于分析原地浸矿过程的边坡稳定具有重要意义。应用水土分合算理论,引入水压率的概念,从土的微观层面上分析水对矿体强度的影响,设计出一种室内测定水压率的试验装置,测定不同孔隙比下的水压率,采用GDS三轴仪测试总应力指标和有效指标,分别计算水土合算、水土分算和水土统一算法下稀土矿体的抗剪强度。渗流产生的动水压力可使弱结合水可成为自由水,通过测定土体无渗流和渗流稳定两种情况下的液塑限值,基于水压率与土的塑性指数的关系,求出渗流稳定时的水压率增加值,得出渗流稳定状态下的水压率值。分析渗流前后寻乌土体的抗剪强度值。运用数值模拟计算不同强度指标下矿体的安全系数,推出原地浸矿时矿体的临界注液强度。通过上述研究,得出以下结论:(1)矿体孔隙比越大,水压率越大;在同等孔隙比下,饱和矿体的抗剪强度随着水压率的增大而增大;寻乌稀土矿体的水压率值为0.90~0.92;,采用水土统一算法计算得到的抗剪强度值与水土分算法的抗剪强度值更接近,与水土合算下的抗剪强度值相差较大。(2)当渗流稳定且渗流速度为3×10-5cm/s时,渗流使弱结合水变成自由水从而引起水压率值增加了0.03,寻乌稀土矿体的水压率值为0.930~0.945;发生渗流时,土体的抗剪强度会变小;在同种孔隙比下,渗流以后的土体抗剪强度值略大于渗流前的抗剪强度值。(3)离子型稀土矿体注液范围增大时,临界注液强度减小;矿体的边坡稳定性分析应采用总应力强度指标更为安全;在同等注液强度时,注液范围增大,矿体会在更短的时间内发生滑坡。
[Abstract]:The ionic rare earth orebody in Xunwu County, Jiangxi Province belongs to silt and is a transitional soil between sandy soil and clay soil. It is of great significance to study the calculation method of shear strength of this kind of orebody for analyzing the slope stability during in-situ leaching. Based on the theory of water and soil distribution, the concept of water pressure ratio is introduced, and the influence of water on the strength of ore body is analyzed from the microcosmic level of soil. An indoor test device is designed to measure the water pressure ratio under different porosity ratio. The total stress index and effective index were measured by GDS triaxial instrument, and the shear strength of rare earth orebody was calculated under the calculation of soil and water, and the unified algorithm of soil and water, respectively. The hydrodynamic pressure generated by seepage can make the weakly bound water become free water. By measuring the liquid-plastic limit value of soil without seepage and seepage stability, based on the relationship between hydraulic pressure and plastic index of soil, The increasing value of water pressure rate is obtained when seepage is stable and the value of water pressure rate under seepage stability is obtained. The shear strength of soil before and after seepage is analyzed. The safety factor of ore body under different strength indexes is calculated by numerical simulation, and the critical liquid injection strength of ore body is deduced when ore is leached in situ. Through the above research, the following conclusions can be drawn: the bigger the porosity ratio of ore body, the greater the water pressure ratio, the more the shear strength of saturated ore body increases with the increase of water pressure ratio under the same void ratio. The water pressure ratio of the Xunwu rare earth orebody is 0.90 ~ 0.92, and the shear strength calculated by the unified soil and water calculation method is closer to the shear strength value of the soil and water component algorithm. When the seepage flow is stable and the seepage velocity is 3 脳 10-5cm/s, the weak bound water becomes free water and the water pressure rate increases by 0.03, and the water pressure rate of the Xunwu rare earth ore body is 0.930 ~ 0.945; when seepage occurs, the water pressure ratio of Xunwu rare earth ore body is 0.930 ~ 0.945. Under the same void ratio, the shear strength of the soil after seepage is slightly larger than that before seepage. 3) when the range of liquid injection of ion rare earth ore body increases, the critical liquid injection strength decreases. In the analysis of slope stability of ore body, the total stress intensity index should be used more safely, and when the liquid injection intensity is equal, the scope of liquid injection will increase, and the ore body will landslide in a shorter time.
【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】：TD854.6;TD865

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