高承台桩灾后无损检测及评估关键技术研究

The objective of this research is to present two new methods for nondestructive testing and assessment of post-disaster tall platform pile foundations-virtual isolation single pile method and universal frequency response function method based on traveling wave decomposition. Firstly, for the first method, calculation models for three exciting modes (vertical, lateral and torsional) are respectively established, and the corresponding excitation methods as well as excitation equipment are developed; for the second method, universal frequency response functions are studied to analyze the pile integrity under test section. Then, programs for the two methods are developed, and repeated verifications are conducted for both methods by model tests and field tests. On this basis, by combining theoretical calculations, model tests and numerical simulation, different influencing factors of universal frequency response function are analyzed, such as physical and mechanical parameters of pile-soil system, exciting position, detection section location and so on. In addition, determination methods of virtual isolation section locations and intervals in various conditions are presented. Meanwhile, coupled vibration characteristics of piles and their superstructures in different conditions are also studied to guide field tests and analyses. Based on all the above work, a more reasonable, liable and effective way is made available to better benefit nondestructive testing and assessment for the tall platform pile after disasters.

建立两种全新的高承台桩灾后无损检测和评估分析方法-"虚拟隔离单桩法"与"基于行波分解的泛频响函数法"。首先，针对"虚拟隔离单桩法"，分别建立纵向、横向及扭转三种激振模式下的分析计算模型，研发相应的激振方法及配套的激振设备；针对"基于行波分解的泛频响函数法"，研究通过泛频响函数分析测试截面以下桩身完整性情况的方法。然后，编制两种检测方法对应的测试分析程序，并利用模型试验及现场试验手段对两种检测方法进行反复验证。在此基础上，结合理论分析、模型试验及数值模拟，研究桩-土体系物理力学参数及激振位置、测试截面位置等测试要素对泛频响函数的影响规律，并分析不同工况下虚拟隔离面位置及间距的确定方法。同时，对不同工况下桩与上部结构耦合振动问题进行研究，以指导现场测试和分析工作，从根本上解决或改善现有检测方法和分析方法的不足，为灾后高承台桩无损检测和评估提供更加科学、可靠的检测手段和分析方法。

建立两种全新的高承台桩灾后无损检测和评估分析方法—“虚拟隔离单桩法”与“基于行波分解的泛频响函数法”。首先，针对“虚拟隔离单桩法”，分别建立纵向、横向及扭转三种激振模式下的分析计算模型，研发相应的激振方法及配套的激振设备；针对“基于行波分解的泛频响函数法”，研究通过泛频响函数分析测试截面以下桩身完整性情况的方法。然后，编制两种检测方法对应的测试分析程序，并利用模型试验及现场试验手段对两种检测方法进行反复验证。在此基础上，结合理论分析、模型试验及数值模拟，研究桩-土体系物理力学参数及激振位置、测试截面位置等测试要素对泛频响函数的影响规律，并分析不同工况下虚拟隔离面位置及间距的确定方法。同时，对不同工况下桩与上部结构耦合振动问题进行研究，以指导现场测试和分析工作，从根本上解决或改善现有检测方法和分析方法的不足，为灾后高承台桩无损检测和评估提供更加科学、可靠的检测手段和分析方法。