为提高隧道衬砌内部缺陷检测方法的精细度、准确性与稳定性，降低漏检、误检风险，提出一种基于超声相控阵技术的隧道衬砌质量精细化检测方法。综合考虑衬砌拱形空间缺陷分布规律及设备检测能力，围绕精细化检测网格与扫描方式提出兼顾检测效率与精细度的全覆盖连续精细化检测方法。精细化检测方法充分利用超声相控阵技术多次覆盖采集与合成孔径聚焦成像性质，与常规逐点敲击及有限测线雷达检测方式相比，能有效提高检测数据的信噪比与分辨率，提升衬砌内部缺陷检测的精细度与成像效果。通过开展衬砌质量精细化检测现场试验，完成了隧道拱顶14 m×4 m（纵向×环向）范围衬砌全覆盖精细化检测，实现了衬砌内部结构高精度三维成像，检测出衬砌内部直径14 mm钢筋及中埋式止水带的分布，验证了本文所提方法的精细化检测能力。
To improve the fineness,
accuracy, and stability of tunnel lining internal defect detection, and reduce
the risk of leakage and misdetection, an elaborate tunnel lining quality
inspection method based on ultrasonic phased array is developed. Comprehensively
considering the defects distribution within lining arch space and the equipment
capacity, a full-coverage continuous elaborate
inspection approach is proposed based on regulate inspection grid and scanning
mode, therefore balancing detection efficiency and fineness. Benefiting from
the multiple coverage acquisition and synthetic aperture focusing imaging
properties of the ultrasonic phased array technology, the signal-to-noise ratio and resolution of the
detection data can be effectively improved, compared to conventional point-by-point tapping and limited-lines radar detection. As a result, the fineness and imaging
effectiveness of the lining internal defects detection can be enhanced. This
method is applied to a practical tunnel to perform elaborate lining inspection
within the scope of longitudinally 14 m × circumferentially 4 m at the tunnel crown, the inspection ability of the method
proposed is verified from detecting 14 mm-diameter
rebar and central-embedded water-stop belt. The internal structure of the tunnel lining is
demonstrated in three-dimensional image, contributing
to accurate identification of the lining internal defects.
