高级检索

深部巷道围岩变形破坏特征与吸能锚杆支护参数设计研究

Study on the deformation and failure characteristics of of deep roadway surrounding rocks and design of energy-absorbing bolt support parameters

  • 摘要: 随着矿山开采深度的逐年增加,巷道围岩的扩容变形和剪胀变形愈发显著,导致围岩失稳现象频发,严重影响了矿产资源的安全高效开发。巷道开挖卸荷后,围岩塑性区的分布形态是影响巷道稳定性的主要原因,其与围岩偏应力场及耗散能分布密切相关。基于此,本文针对金川矿区开展了不同工况下深部巷道围岩变形破坏和能量耗散规律研究。首先,通过现场调研总结了深部巷道围岩破坏的原因,并基于三维激光扫描获取了围岩节理裂隙的空间分布信息。随后,结合Unwedge软件修正了RMR岩体质量分级方法,并采用RockData软件获取了不同岩性岩体的基本力学参数。最后,基于FLAC3D软件构建了含复杂节理裂隙的巷道数值模型,通过Fish语言开发了深部巷道围岩的风险系数和能量分析模块,研究了不同工况下深部巷道围岩的风险区和耗散能演化规律。结果表明:不同工况下巷道围岩塑性区、偏应力场、围岩耗散能分别呈圆形、椭圆形和蝶形分布;岩性和埋深仅改变围岩的塑性区体积、偏应力和耗散能的大小,并不影响其分布形态;而巷道断面形状和侧压系数同时改变形态分布和数值大小;基于围岩风险区和耗散能分布形态确定了吸能锚杆的设计长度和数量,从而抑制围岩塑性区进一步扩展,减少巷道围岩支护强度不足或支护过度现象的发生。

     

    Abstract: As the mining depth increases annually, the dilation ans shear deformation of roadway surrounding rocks have become increasingly significant, leading to frequent occurrences of surrounding rock instability, which seriously affects the safe and efficient exploitation of mineral resources. After roadway excavation and unloading, the plastic zone distribution of surrounding rocks, closely related to the deviatoric stress field and dissipative energy, is the primary factor affecting roadway stability. Therefore, this paper investigates the deformation, failure, and energy dissipation of deep roadway surrounding rocks under different working conditions in the Jinchuan mining area. Firstly, the causes of structural failure in deep roadway surrounding rocks in Jinchuan mine were summarised through on-site investigation, and the spatial distribution information of surrounding rock joints and fissures was obtained using 3D laser scanning technology. Subsequently, the RMR rock mass quality classification method was modified in combination with Unwedge software, and basic mechanical parameters of rock masses with different lithologies were acquired using RockData software. Finally, a numerical model of the roadway containing complex joints and fractures is developed based on FLAC3D software. A risk coefficient and energy analysis module for deep roadway surrounding rocks was developed using Fish language to study the risk zones and dissipative energy evolution under different working conditions. The results show that the plastic zone, deviatoric stress field, and dissipation energy of surrounding rocks under different working conditions exhibit circular, elliptical and butterfly shapes. Lithology and burial depth only alter the plastic zone volume, as well as the magnitude of deviatoric stress and dissipative energy, without affecting their distribution patterns. In contrast, the roadway cross-sectional shape and lateral pressure coefficient influence both their distribution patterns and values. Based on the distribution patterns of the risk zones and dissipative energy of surrounding rocks, the length and quantity of energy-absorbing bolts were determined to inhibit further expansion of the plastic zone and reduce insufficient or excessive support in roadway surrounding rocks.

     

/

返回文章
返回