论文部分内容阅读
地质雷达运用于箱梁底板钢筋保护层密实度探测时因钢筋保护层客观上薄,且存在密集钢筋网的强干扰的特点,其剖面图不密实异常体的识别存在较大的难度。本文基于时域有限差分法,设定模型进行正演数值模拟,探讨雷达剖面图中不密实异常体的识别方法。结果显示保护层中的不密实体的存在会干扰钢筋网的绕射波形,反过来钢筋网的绕射波形的一些特征可以辅助我们对于保护层中不密实异常体的识别。将这些特征运用到箱梁底板钢筋保护层密实度探测实例分析中,得出钢筋网绕射波形的特征较好的辅助我们对于不密实体的识别。
When using GPR to detect the densification of reinforced protective layer in the bottom of box girder, the protective layer of reinforced bar is objectively thin and there is the strong interference of dense reinforcing steel mesh. There is great difficulty in identifying the abnormal body in section view. Based on the finite difference time domain method, the model is set up to simulate forward modeling, and the recognition method of the anomalous body in radar profile is discussed. The results show that the existence of imperfect solid in the protective layer can disturb the diffraction of the steel mesh. In turn, some of the characteristics of the diffraction pattern of the steel mesh can help us identify the non-dense abnormal body in the protective layer. Applying these characteristics to the case analysis of the densification of reinforced protective layer on the floor of the box girder, we can draw the conclusion that the characteristics of the diffraction waveform of the reinforcing steel mesh are better for assisting our identification of the non-compacted solid.