| There are over 10,000 road tunnels in Japan and inspection are carried out on several regulationsand technical standards. If deformation or structural defect such as crack and shortage of lining thickness wasfound, the countermeasures would be chosen and the time for implementation would be discussed. However,only the qualitative evaluation was almost done practically and the measures were almost selected referring to thepast examples. In order to achieve the proper maintenance, it is essential to acquire the information such assituation of crack, cavity behind lining and thickness of lining through inspection and to set up the evaluationmethod of tunnel health by quantitative methodology. In this paper, defect examples of scaling and spalling oflining were collected, which hammer test was done and the degree of deformation and defect was judged by thecurrent technical guidelines. Also, the validity of items such as the degree of the acoustic quality by hammeringlining, the degree of fall-off of lining debris, and crack information was discussed to establish the quantitativemethod of health evaluation of tunnel. Finally the formula and concept, which included the possibility ofquantitative method of health evaluation for scaling and spalling, were proposed. |
