深部砂土—煤系风化岩接触带力学特征研究

发布时间：2018-04-02 12:06

本文选题：土-岩接触带　切入点：风化带　出处：《中国矿业大学》2015年硕士论文

【摘要】：巨厚表土覆盖隐伏煤田在我国广泛分布,缩小保护煤岩柱提高开采上限,意味着地下采煤活动离深部土-煤系风化岩接触带更近。东部矿区多年近“带”开采的实践表明:有成功采出滞压煤体,延长矿井服务年限,提高生产效益的实例;也有突水溃砂、矿压异常增大,威胁矿井安全生产等问题的出现。深部土-煤系风化岩接触带是由深部土、水、风化破碎岩组成,经长期水-土-岩相互作用地质过程作用,整体强度较低、力学性质有递变特征的特殊工程地质岩组,承接了上覆土体与下伏岩体间采动不协调变形。本文以砂土-煤系风化岩接触带为研究对象,从开采扰动和风化带物理力学性质两方面展开研究:①以弹塑性有限差分计算数据为基础,总结了风化带岩土体在采动扰动下的应力路径并将其概化为6种三轴试验加卸载模式;②以风化岩替代材料的配比试验为依据,制作了具有强度连续性特征差异的三轴试验组合试样;③开展土-岩接触面高压直剪试验、土-岩接触带减压三轴压缩试验和风化带粘土矿物膨胀性试验,测试得到土-岩接触面/带的Mohr-Coulomb抗剪强度指标和风化带粘土矿物的膨胀性指标。以试验测试数据为基础,建立了考虑强度连续性特征的三参数模型。进而将风化带岩土体的强度梯度量化为强度连续性指标并引入三参数模型,建立了土-岩接触带三参数模型。
[Abstract]:The overlying coal fields covered by the super-thick topsoil are widely distributed in China, which means that the underground coal mining activities are closer to the deep soil-coal measures weathered rock contact zone by reducing the protection coal pillar and raising the mining upper limit.The practice of mining near the "belt" for many years in the eastern mining area shows that there are some examples of successful mining of stagnant coal body, prolonging mine service life and improving production benefit, and there are also some problems such as water bursting, abnormal increase of mine pressure and threats to mine safety in production.The contact zone of deep soil-coal measures weathered rock is a special engineering geological rock group which is composed of deep soil, water and weathered broken rock. After a long period of geological process of water-soil-rock interaction, the overall strength of the contact zone is low and the mechanical properties have progressive characteristics.The disharmony deformation between the overlying soil and the underlying rock mass is carried out.In this paper, the contact zone of sand and coal measures weathered rock is taken as the research object, and the study on the two aspects of mining disturbance and physical and mechanical properties of weathering zone is carried out on the basis of elastic-plastic finite difference calculation data.This paper summarizes the stress path of weathered rock and soil under mining disturbance and generalizes it into six triaxial test loading and unloading modes.Triaxial test specimens with different strength continuity characteristics were made to carry out direct shear tests at high pressure on soil-rock contact surfaces, triaxial compression tests under pressure in soil-rock contact zones and swelling tests on clay minerals in weathered zones.The Mohr-Coulomb shear strength index of soil-rock interface / zone and the swelling index of clay minerals in weathered zone are obtained.Based on the test data, a three-parameter model considering the continuity of strength is established.Furthermore, the strength gradient of rock and soil in weathered zone is quantified as the strength continuity index and the three-parameter model is introduced, and the three-parameter model of soil-rock contact zone is established.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD313

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