Establishment of Diagnostic Methods for Infrastructure

对于基础设施的诊断方法，本研究对世界范围内的无损检测和评价体系进行了综述。根据研究人员感兴趣的领域，可分为六个研究领域。一是声发射技术在混凝土结构诊断中的应用。发展了声发射弯矩张量分析，并将其应用于混凝土结构的开裂机理识别。二是混凝土的无损检测。超声波、半电池电位测量、雷达检测和热成像技术被研究和发展用于原位观察。三是混凝土构件无损评价及断裂机理。为了评估混凝土结构的劣化过程，在断裂力学的基础上进行了无损评价。这导致了对恶化的定量评估。四是钢结构无损检测与损伤评价。检查的主要对象是钢构件的缺陷。第五部分是桥梁结构劣化过程预测，第六部分是桥梁维修专家系统。因此，评估程序进行了调查，并开发了新的系统。由于最近有报道称，由于世界各地的老化和灾害，许多土木结构将达到其使用寿命极限，因此迫切需要进行研究。因此，最后提出了更新的方法摘要。该报告非常全面，可以适用并有助于基础设施的各种诊断程序。

Concerning the diagnostic methods for infrastructure, nondestructive inspections and evaluation systems are surveyed worldwide in this research. Related with the interested fields of investigators, these are categorized into six research fields. The one is the application of acoustic emission (AE) to diagnosis of concrete structures. AE moment tensor analysis is developed and applied to concrete structures to identify cracking mechanisms. The second is nondestructive testings of concrete. Ultrasonics, half-cell potential measurement, radar inspection, and thermography are investigated and developed for in situ observation. The third is nondestructive evaluation and fracture mechanisms of concrete members. In order to estimate the deterioration process of concrete structures, nondestructive evaluation is conducted on the basis of fracture mechanics. This leads to quantitative evaluation of the deterioration. The fourth is nondestructive testings and damage evaluation of steel structures. The main target for inspection is the defects in steel members. The fifth is prediction of the deterioration process of bridge structures, and the sixth is the expert systems for bridge maintenance. Thus, evaluation procedures are surveyed and new systems are developed.Since it is recently reported that many of civil structures are going to reach their service-life limit due to aging and disasters all over the world, the research conducted is in urgent demand. Accordingly, the updated summary of the methods is eventually proposed. The report is so comprehensive as to be applicable and able to contribute to a variety of diagnostic procedures for infrastructure.