水灰比对高水材料力学特性影响的试验研究

发布时间：2018-02-01 09:52

本文关键词： 水灰比高水材料微观结构强度特性　出处：《工程科学与技术》2017年S2期 　论文类型：期刊论文

【摘要】：充填开采是实现矿山绿色开采的有效方式,研究量大适宜的充填材料成为充填开采技术应用的关键。高水材料是一种新型矿山充填材料,其受压后的物理力学性能直接影响采空区充填体的稳定性。固体颗粒和水作为高水材料主要的组成物质,其相对含量直接影响高水材料的物理力学特性。利用宏观与微观相结合的综合试验方法,对高水材料在不同水灰比条件下的基本物理性能和强度特性进行了系统研究,结果表明:高水材料结石体微观结构呈网状结构,且具有稀疏多孔等特点,使其可以吸附自身重量数倍的水。水灰比越大,网状结构中孔隙越稀疏,从而形成更大的孔隙结构。高水材料具有与岩石类似的应力应变曲线,但高水材料塑性极高,达到峰值强度后仍能保持较好的完整性。单轴压缩条件下,高水材料会出现明显的析水现象,水灰比越大,析水现象越严重。在单轴压缩条件下,高水材料有"X"型共轭剪切破坏、单斜剪切破坏和拉伸破坏等几种典型的破坏类型。水灰比较高时,高水材料常呈"X"型剪切破坏;水灰比较低时,常为劈裂破坏。高水材料单轴峰值强度和残余强度均随水灰比的增大而减小,水灰比越小其应力应变曲线峰值处越陡峻,峰后强度下降得越快,但其残余强度仍保持较高水平。该种材料塑性较好,残余强度较高,适合作为地下矿山采空区的永久充填材料。
[Abstract]:Filling mining is an effective way to realize green mining in mines. The research on large and suitable filling materials is the key to the application of filling mining technology. High water material is a new type of filling materials in mines. Its physical and mechanical properties directly affect the stability of goaf filling. Solid particles and water are the main components of high water materials. Its relative content directly affects the physical and mechanical properties of high-water materials. The basic physical properties and strength characteristics of high-water materials under different water-cement ratios were systematically studied. The results showed that the microstructure of high-water stone bodies was reticular and had the characteristics of sparse and porous. The larger the water-cement ratio, the more sparse the pores in the reticular structure, thus forming a larger pore structure. The high-water material has a stress-strain curve similar to that of the rock. However, the plasticity of high water material is very high, and it can maintain good integrity after reaching the peak strength. Under uniaxial compression condition, the water evolution phenomenon will appear obviously in high water material, and the water cement ratio will increase. The phenomenon of water evolution is more serious. Under uniaxial compression condition, there are several typical failure types such as "X" conjugate shear failure, monoclinic shear failure and tensile failure. High water materials are often subjected to "X" shear failure. The uniaxial peak strength and residual strength of high-water materials decrease with the increase of water-cement ratio. The smaller the water-cement ratio is, the steeper the peak value of stress-strain curve is, and the faster the post-peak strength decreases. However, the residual strength of this kind of material is good in plasticity and high in residual strength, so it is suitable for permanent filling in goaf of underground mines.
【作者单位】：四川大学水力学与山区河流开发保护国家重点实验室水利水电学院;四川电力设计咨询有限责任公司;香港科技大学土木与环境工程系;四川大学-香港理工大学灾后重建与管理学院;
【基金】：国家自然科学基金资助项目(51604006;51369001)
【分类号】：TU599
【正文快照】： 在中国一次能源结构中煤炭长期占70%左右,并且这一主体地位在未来相当长的时间内不会改变[1]。中国煤炭资源,大多是以地下开采方式采出的,全部垮落法是国内外处理采空区的主要方式[2]。然而,全部垮落法会诱发一系列环境问题,如严重破坏地形地貌等自然景观,严重损坏地面及地下

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