点検データの不足を補うトンネル劣化予測手法

摘要

In general, it is difficult to conduct renewals of tunnel structures. In cases where deterioration or damage has occurred on them, massive countermeasures are essential and these require high operation and maintenance costs. For that reason, it is considered that there is a need to convert to preventive operation and maintenance by utilizing such things as past inspection records. However, it is the current situation that the usable information is scarce for tunnels aged dozens years and older due to such things as missing of necessary information.The subject of this study was a road tunnel in Nagasaki Prefecture. The degree of soundness of the tunnels was judged for each span of concrete form based on scarce information on such things as cracks, water leakage, exfoliation, etc. We set the state transition probability with a focus on the ratio of damaged spans to total and proposed a deterioration prediction model based on the Markov probability theory. As a result, it was confirmed that degree of soundness and evaluation by deterioration prediction models match comparatively well. It is thought that it will be possible to apply this to future efficient and effective operation and maintenance for tunnels because the method's validity was confirmed as a deterioration prediction for road tunnels which information is scarce.%トンネル構造物は一般的に更新を行うことが困難であり，劣化や損傷が生じた場合には，大規模な対策が必要となり，rn多額の維持管理費用が必要となる．そのため，過去の点検記録などを活用した予防保全型の維持管理へ転換を図る必要rnがあると考えられる．しかし，構築後数十年以上経過したトンネルでは，必要な情報が紛失しているなど，活用できるrn情報が少ないのが現状である．本研究では，長崎県の道路トンネルを対象にひび割れ，漏水，うき・剥離などの数少なrnい情報をもとに，トンネルのスパンごとに健全度を判定し，全スパンに占める損傷スパンの割合に着目して遷移確率をrn設定して，マルコフ過程による劣化予測モデルを提案した．その結果，健全度と劣化予測モデルが比較的よく一致するrnことが確認され，情報が少ない道路トンネルの劣化予測手法としての有効性が確認され，今後の効率的・効果的な維持rn管理に適用できるものと考える．