基于渗流作用被锚巷道弹塑性分析

(1.中煤科工集团 西安研究院有限公司,陕西 西安 710077; 2.西安科技大学 管理学院,陕西 西安 710054; 3.西安科技大学 建筑与土木工程学院,陕西 西安 710054)

巷道; 全长黏结锚杆; 渗流作用; 围岩强化; 弹塑性分析

Elastoplastic analysis of anchored roadway based on seepage
FAN Qi1,LI Hong-xia2,LI Xiao-dong3

(1.Xi'an Research Institute,China Coal Technology and Engineering Group,Xi'an 710000,China; 2.College of Management,Xi'an University of Science and Technology,Xi'an 710054,China; 3.College of Civil and Architectural Engineering,Xi'an University of Science and Technology,Xi'an 710054,China)

roadway; fully grouted rock bolt; seepage; surrounding rock reinforcement; elastoplastic analysis

DOI: 10.13800/j.cnki.xakjdxxb.2019.0313

备注

为研究渗流作用下全长黏结锚杆支护巷道围岩应力与位移分布,通过将巷道围岩视为均匀、连续的多孔介质,锚杆对围岩的支护反力与渗流作用力转化为圆形巷道轴对称径向体积力并同时作用于应力场,考虑锚杆对围岩参数的强化,建立力学模型,采用弹塑性分析方法,推导了围岩应力与位移弹性解析解和基于Mohr-Coulomb屈服准则的塑性解析解,求得巷道围岩塑性区半径和洞壁位移表达式,在此基础上可对理解渗流作用下锚杆支护巷道进行分析判断。结果 表明:本文计算的理论解与FLAC3D数值模拟结果相近,从而验证了本文理论的合理性; 通过算例,考虑渗流作用对塑性区范围和洞壁位移影响更严重; 锚杆长度和预紧力与塑性区范围和洞壁位移成反相关关系,锚杆排距与塑性区范围和洞壁位移成正相关关系。锚杆支护参数对支护效果更敏感。在相同的条件下,考虑渗流需要锚杆提供更大的锚固力。为避免渗流作用引起巷道失稳,可合理增大锚杆长度,缩小锚杆排距,增大锚杆预紧力。

To study the stress and displacement distribution of the surrounding rock of roadway supported by full-length bonded bolt under seepage,the surrounding rock of roadway was treated as uniform and continuous porous medium,and the supporting force and seepage force of the surrounding rock are transformed into the circular roadway axisymmetric radial volume force acting on the stress field simultaneously.Considered the reinforcement of the surrounding rock parameters by the bolt,the mechanical model was built.The elastoplastic analysis method was used to derive the analytical solution of the stress and displacement elasticity of the surrounding rock and the plastic analytical solution based on Mohr-Coulomb yield criterion to obtain the expressions of the radius of the plastic zone of the roadway and the displacement of the wall.On this basis,the bolt support under the action of seepage was analyzed.Results show that the theoretically calculated solution in this paper is similar to the FLAC3D numericalsimulation results,which verifies the rationality of the theory.An example indicates that the influence of the seepage on the plastic zone range and the wall displacement is more serious,the length and pre-tightening force of the bolt are inversely related to the plastic zone range and the displacement of the wall,and the bolt row spacing is positively correlated with the plastic zone range and the displacement of the wall.The bolt support parameters are moresensitive to the support effect.Under the same conditions,considered that the seepage requires the bolt to provide greater anchoring force,the length of the bolt should be reasonably increased,the bolt spacing should be reduced,and the bolt pre-tightening force should be increased in order to avoid the instability of the roadway caused by the seepage.