软岩巷道二次支护时机研究

Research on secondary support time of soft rock roadway

为了准确地确定二次支护时机,基于软岩巷道工程支护原理,分析了软岩巷道支护过程中围岩应力与强度调整过程,结合软岩巷道流变数学力学模型,并以弹性区、塑性区、破裂区的力学行为与岩石全应力-应变的对应关系作为基础,最终确定了二次支护最佳时间的理论公式。分析了二次支护最佳时间的影响因素及规律,并将二次支护时机理论公式应用于工程实践。结果表明,按照该理论公式设计二次支护时机能够较好地控制巷道围岩的稳定性。

In order to determine accurately secondary support time,the adjustment process of surrounding rock stress and strength in the course of supporting is analyzed based on the support principle of soft rock roadway. Based on the rheological model of soft rock roadway and the corresponding relationship between the mechanics behaviors of elastic zone,plastic zone and fractured zone and rock complete stress-strain process,the theoretical formula of secondary support time is proposed. Then the influential factors and rules of secondary support time are analyzed. To validate the study,the secondary support time theory is applied to engineering practice. Results show the roadway maintains a good stability according to the proposed secondary support time.