【作者】 孙琦；

【导师】 张向东；

【作者基本信息】 辽宁工程技术大学 ， 岩土工程， 2013， 博士

【摘要】 煤矿开采造成的沉陷灾害严重危害了矿区的环境和建筑物的稳定,因此控制矿山开采沉陷灾害对煤矿生产十分重要。膏体充填开采作为煤矿绿色开采和科学开采的重要手段,得到了广泛应用,与其他充填材料相比,膏体充填材料具有刚度大、减沉效果好的特点,但长期以来对膏体充填开采胶结体的力学特性研究主要集中在弹塑性方面,对充填开采胶结体的蠕变特性研究较少,因此在研究充填胶结体强度的基础上,重点研究其三轴蠕变特性,建立符合充填胶结体特性的蠕变本构方程,具有重要的现实意义。通过多组单轴压缩试验,分析了膏体充填开采胶结体的早期强度影响因素,研究了强度和变形特性。以单轴压缩强度为依据,进行了不同应力水平下的三轴蠕变试验,建立了充填开采胶结体的蠕变损伤本构模型,得到了充填开采胶结体的长期力学参数。并以充填胶结体的长期力学参数为依据进行了数值模拟,分析了公路下和边坡下膏体充填开采的规律,同时采用模型试验进行了公路下膏体充填开采的研究,验证了试验设计的充填材料具有良好的充填效果。研究结果表明：(1)膏体充填开采胶结体的早期强度与早强剂添加量、胶凝材料用量正相关,与水胶比负相关,试验设计的膏体充填开采胶结体具备较大的早期强度和后期强度,能够抵抗上覆岩层传递的荷载,且具备弹性模量较大的特点；(2)膏体充填开采胶结体具有明显的流变特性,当应力水平较低时,其蠕变仅有衰减蠕变和稳态蠕变两个阶段,当应力水平较高时,随着应变值的增大,会出现加速蠕变；(3)建立了弹性模量将随应力、时间变化的损伤演化方程,并将损伤变量引入到一个串联应变触发的非线性粘壶的改进西原模型中,建立了蠕变损伤本构模型,该模型能够较好地反映充填开采胶结体的蠕变规律；(4)采用试验设计的膏体充填材料进行公路下和边坡下膏体充填开采,能够满足充填开采的要求；公路路面的下沉值与充填高度正相关,与充填开采胶结体的弹性模量、采煤倾角、采深负相关；使用膏体充填开采时边坡的安全系数达到了1.28,保证了边坡的稳定性。更多还原

【Abstract】 The mine environment and buildings’ safety were seriously influenced by the subsidencedisaster result from mining. So the control of the mining subsidence was very important to thecoal mining. The backfilling mining with paste was widely used in the coal mining as a kind ofgreen and scientific mining method. Contrasted to other backfilling materials the paste’s stiffnesswas larger and its effect for decreasing subsidence was better. But the researches on the pastecemented body’s creep properties were scarce while the researches were focused on itselastoplasticity characteristics. In this paper, the paste cemented body’s strength was studiedfirstly. Then its triaxial creep properties were researched and the scientific creep constitutiveequation on the early strength was constructed.The early strength’s influence factors, strength and deformation features of the pastecemented body were analyzed on the bases of multigroup uniaxial compression tests. Based onthe paste cemented body’s uniaxial compression strength its triaxial creep tests with differentstresses level were done and its creep damage constitutive model was derived and its long-termmechanical parameters were obtained. Then the laws of backfilling mining with paste underhighway and slope were analyzed after their numerical simulation. At the same time the mock-uptest on the backfilling mining with paste under highway was carried out and the well effect forthe control of subsidence was confirmed.The research results and conclusions were as follows:(1) The early strength of the paste cemented body would be larger when the early strengthagent or the binding material was more but it would be smaller when the water-binder ratio waslarger. The paste cemented body in the mock-up test was equipped with larger early strength andlong-term strength and could resist the overburden load and had larger modulus of elasticity.(2) The paste cemented body had obvious rheological behaviors. It had attenuation creepand steady creep when the stress was small. But the accelerated creep phenomenon would occurwith its strain was larger and larger when its stress continued increasing.(3) The damage evolution equation where the time and stress were considered was derived.The damage variable was taken into account in the modified visco-elastic plastic model whichincluded a nonlinear adhesive pot which was triggered by series connection strain. Then the creep damage constitutive model was established. And the creep law of the paste cemented bodywas explained well through the creep damage constitutive model.(4) The backfilling mining under highway and slope with the paste material in the mock-uptest could satisfy the control for the subsidence. The subsidence value of the highway would belarger when the backfilling height was larger but would be smaller when the paste cementedbody’s modulus of elasticity or the coal bed pitch or the mining depth was larger. The slope’ssecurity coefficient was1.28when the backfilling mining with the paste was used. So the slopewas safe.更多还原