基于弹性动力学的爆破动剪切荷载锚喷支护参数研究

Research on Shotcrete-rock Bolt Support Parameters on Blasting Dynamic Shear Load based on Elastokinetics

为得到爆破动力作用下的锚喷支护参数,在引入"转换因子"的基础上,采用"升维法"推导三维柱坐标下的平面剪切波波动方程,得到能量密度表达式和总能量表达式,再据此获得锚固后岩体的剪切波分布面积增大系数,从弹性动力学这个新的角度一定程度上揭示了爆破动剪切荷载锚喷支护机理,提出了确定锚固参数的新思路。以软岩隧道为具体工程应用对象,基于围岩稳定性分级,采用振幅衰减法和分布面积增大系数法对其锚固参数进行了设计计算,与传统方法相比,该方法不仅计算结果与传统方法计算结果保持一致,还能较大程度上减小确定锚固参数的难度。

In order to obtain the shotcrete-rock bolt support parameter on blasting dynamic load, the motion equation of plane shear wave on 3D cylindrical coordinates was derived by ＂raising dimension method＂ on the basis of ＂conversion factor＂, by which the energy density and the total energy expressions were obtained, further the shear wave distribution area enlargement coefficient was put forward. To certain extent, the blasting dynamic shear load mechanism was revealed on rock bolt and shotcrete, and a new way to determine the anchorage parameters was put forward. With a soft rock tunnel as actual engineering object, based on the stability of surrounding rock classification, the amplitude decay method and the distribution area enlargement coefficient method were used to simulate the an- choring parameters for the design and calculation. Calculated results by the method were consistent with the tradition- al method, but reduced the difficulty of determining the anchorage parameters greatly compared with the traditional method.