基于大变形升阻锚索深埋巷道围岩稳定性控制研究

Stability control of deep-buried roadways using large deformation and increasing resistance anchor cables

研发了一种新型大变形升阻锚索支护结构,通过串联6个壁厚5 mm含环形V槽的直管型钢结构实现锚索吸能让压,吸能率为44.55 J/g。拉拔试验结果表明新型锚索极限变形量(221.58 mm)与普通传统锚索相比增加了4.87倍,具有大变形、增阻及高吸能等优良性能。通过离散元UDEC程序的二次开发,模拟了新型大变形增阻锚索支护阻力−变形曲线的双弹性阶段。采用新型锚索对深埋巷道围岩支护效果数值模拟结果表明,与无支护及传统锚索支护相比,顶板下沉量分别减小了88.33%与74.64%,稳定状态下最大主应力峰值分别减小了23.15%与18.34%,塑性区厚度分别减小了37.50%与62.50%。最后将新型大变形增阻锚索成功应用于真实巷道,两帮最大收敛变形量约为300 mm,实现了较好的支护效果。

A new large deformation and increasing resistance anchor cable was developed.The energy absorption and pressure release were achieved through connecting six straight tube-shaped steel structures(thickness of 5 mm)containing a circular V-shaped groove in series,with the energy absorption ratio of 44.55 J/g.The pull-out experiment indicates that the ultimate deformation(221.58 mm)of the new anchor cables is 4.87 times larger over that of traditional anchor cables,achieving good properties of large deformation,increasing resistance and high energy absorption.Through secondary development of the universal discrete element code(UDEC),two elastic deformation stages of the supporting resistance−deformation curves for anchor cables were simulated.The numerically simulated supporting effects of the new anchor cables on deep-buried roadways show that the roof subsidence decreases by 88.33%and 74.64%,the peak maximum principal stress at stable states declines by 23.15%and 18.34%,and the thickness of plastic zones decreases by 37.50%and 62.50%,respectively,compared with those of the roadways with no support and traditional anchor cable support.Finally,the new-developed anchor cables were successfully applied in real roadways,with the maximum convergence deformation for the two sides of approximately 300 mm,achieving a good supporting effect.