超声波层析成像在桩身结构完整性诊断中的应用

应用声波在桩身中传递的网格法射线追踪原理，采用逐次线性化迭代与带阻尼最小二乘QR分解相结合的超声层析成像方法进行图像重建。通过预设置缺陷的模型桩测试，对基于超声波速和特征阻抗的层析成像结果进行了分析验证。结果表明，超声层析成像技术应用于基桩完整性诊断中，可判定灌注桩桩身缺陷的位置和形状大小，并能达到较高的精度。特别是基于特征阻抗的层析成像，为基桩完整性的定量诊断提供了精确的数据平台，在基桩完整性诊断和对缺陷的工程处理方面具有较高的应用价值。

Application of ultrasonic computerized tomography to diagnosis of pile construction integrity

The article tries to carry out the image reconstruction of pile body based on the principle of ray tracing with grid, and by using the method of ultrasonic tomography, which combines successive linearization iteration with least square QR decomposition with damping. According to test results of model piles with defects to be pre-set, ultrasonic tomography method is used to analyze the ultrasonic velocity and its characteristic impedance. The results show that the ultrasonic tomography method can be applied to the integrity testing of pile foundation, and to identify the position, shape and size of defects of pile body in the cast-in-place pile. Moreover, it can reach the higher precision. Especially, for analyzing the characteristic impedance, it can provide the exact data for the quantitative testing of integrity of pile foundation. Therefore, it will have higher application value in the integrity testing of pile foundation and geoengineering treatment of defects.