深部大跨度巷道钻孔卸压与双微拱减跨支护机理

The stability control of deep and large-span roadway is one of the technical problems to be solved urgently, and the technical of borehole destressing and double micro arches’s reducing-span is an effective way to control that problem.Therefore, basing on the mechanism of destressing and reducing-span support, lab experiments and field tests,the project carried out the following main researchs:(1)The model for determining the instability of deep and large-span roadway is established to reveal the instability mechanism of deep and large-span roadway.(2)we study the spatial and temporal evolution characteristics of the stress field of the surrounding rock of deep and large-span roadway, and analyse the damage evolution and strength attenuation process of pressure-releasing surrounding rock mass,which reveals the drillhole pressure-releasing mechanism of deep and large-span roadway. (3)We establish the mechanical model of double micro arches’s reducing-span , and analyse the stress and deformation of surrounding rock of double arch roadway,which reveals the mechanism of action of double micro arches’s reducing-span support.(4)In order to reveal the law of deformation-damage and strength attenuation of pressure-releasing double flat arched section roadway anchor structure and determine the degree of pressure relief, the size of the double arch section, the corresponding dynamic control technology and timing,we establish the mechanical model of drillhole pressure-releasing and double flat arched section roadway anchor structure which has deformation and damage to study the effects of factors including the parameters of drilling pressure relief, pressure relief time and the parameters of double flat arched section on roadway stability.The results can provide the basis for the research on the technology of " drillhole pressure-releasing and double arch span reducing support" in deep and large-span roadway.

深部大跨度巷道稳定控制是国家亟需解决的技术难题之一，而钻孔卸压与双微拱减跨是控制深部大跨度巷道稳定的有效方法。为此，本课题基于卸压与减跨支护理论、室内实验和现场实测，主要开展以下研究内容：（1）建立深部大跨度巷道失稳判定模型，揭示深部大跨度巷道失稳机理。（2）研究钻孔卸压深部大跨度巷道围岩应力场时空演化特征，分析卸压围岩锚固体损伤演化与强度衰减过程，揭示深部大跨度巷道钻孔卸压机理。（3）建立双微拱断面巷道减跨力学模型，分析双微拱断面巷道围岩应力与变形规律，揭示双微拱减跨支护作用机理。（4）建立钻孔卸压-双微拱断面巷道锚固体结构的变形-损伤力学模型，研究钻孔卸压参数、卸压时机、双微拱断面参数等因素对巷道稳定的影响规律，揭示卸压双微拱断面巷道锚固体变形损伤及其强度衰减规律，确定卸压程度、双微拱断面尺寸、相应动态控制技术和时机，为研究深部大跨度巷道“钻孔卸压-双微拱减跨支护”技术提供依据。

深部大跨度巷道失稳垮冒现象时有发生，已成为煤矿亟待解决的重大技术难题。深部大跨度巷道稳定控制是国家亟需解决的技术难题之一，而钻孔卸压与双微拱减跨是控制深部大跨度巷道稳定的有效方法。本课题基于卸压与减跨支护理论，采用室内实验、理论分析、数值模拟和现场实测等方法，系统研究了深部大跨度巷道钻孔卸压与双微拱减跨支护机理，取得了一下主要研究成果：.（1）基于复变函数理论，运用施瓦茨-克里斯托菲尔求解映射函数的方法，推导出大跨度矩形巷道围岩应力与位移的计算公式，通过具体实例，计算得到了矩形巷道内部各点应力与位移的数值解，分析了矩形巷道围岩应力与变形规律。.（2）揭示了巷道围岩塑性区分布形状随侧压的变化规律，给出了大跨度巷道的定义，划分了大跨度巷道类型；建立力学模型，给出了巷道顶板及两帮失稳判据，通过相似模拟分析了深部大跨度巷道顶板垮冒的动态变化，揭示了深部大跨度巷道失稳垮冒机理。.（3）分析了大跨度钻孔卸压围岩应力时空演化规律；建立钻孔卸压力学模型，基于现场实测数据，结合数值模拟分析并得到了大跨度巷道钻孔卸压对巷道围岩稳定性影响规律，揭示了深部大跨度巷道卸压机理。.（4）模拟分析了卸压钻孔单孔影响范围，给出了深部大跨度钻孔卸压时机、参数的确定方法，提出了变孔径钻孔卸压技术，并分析其卸压原理与技术方法，形成了深部大跨度巷道钻孔卸压技术体系。.（5）提出了双微拱断面巷道的概念，建立了双微拱巷道的力学分析模型，得到双微拱巷道应力、位移的表达式，分析了双微拱断面巷道围岩应力与变化规律。揭示了双微拱断面减跨支护机理，给出了深部大跨度巷道双微拱断面减跨支护方法与技术。.（6）分析了钻孔卸压参数、时机等因素对双微拱断面巷道锚固体变形的时空影响规律，给出了深部大跨度巷道“钻孔卸压-双微拱减跨支护”方法与技术。研究成果在潞安五阳煤矿7801切眼和中煤井工一矿进行了现场工业性试验，取得了良好的效果，推广应用前景广泛。