Finite element method was used to simulate longitudinal guided wave reflecting from the upper interface of partially grouted bolt, with the excitation wave frequencies 5 ～ 60 kHz. Reflection coefficient was used to evaluate the upper interface reflection wave which can be seen clearly while reflection coefficient was large. The effect of thickness of the grout layer, wedge angle between the upper interface and the bolt axial direction and grout materials on the upper interface reflection wave was studied. The results show that the factors above have little effect on reflection coefficient with the same excitation wave frequency, and reflection coefficient is larger when the excitation wave frequency is lower than 20 kHz, and reflection coefficient reaches its minimun when the frequency is 40 kHz. The results of numerical simulation agree well with the experimental results.%利用有限元数值模拟研究了5～60 kHz纵向导波在端锚锚杆锚固段上界面的反射情况.使用反射系数衡量导波在锚固段上界面反射能量的大小,反射系数越大,即导波在锚固段上界面的反射越明显.通过改变锚固层厚度、锚固段上界面与锚杆轴向间的楔角和锚固层的材料,研究了反射系数的变化.結果表明,以上因素对同频率导波的反射系数影响不大;当激发波频率低于20 kHz,反射系数较大;而频率为40 kHz时,反射系数最小.数值模拟导波在锚固段上界面反射系数与现场测试所得结果吻合较好.
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