私たちの研究室では、地盤災害の発生直後に現地へ赴き、被害の全容を多角的な視点から調査しています。大地震や豪雨災害などの自然災害が発生すると、多くの関係者が必ずしもすぐに現場へ行けるわけではありません。しかし、地盤がどのように崩壊し、どんな被害形態が起こったか、あるいは被害を軽減した成功事例がどの程度効果的だったかを、客観的かつ定量的に記録することは、次の防災技術を大きく進化させる基盤となります。
たとえば、熊本地震やインドネシア・スラウェシ地震では、緩やかな勾配でも発生する大規模な地盤流動が注目されました。従来の常識からは想定外に思える現象が現場で観察されると、それまでの研究や設計基準を再考し、新たな地盤強度評価手法や対策技術を検討する必要が出てきます。また、被害だけでなく、実は被害が出なかった地域や構造物が「なぜ無事だったのか」を調べることも極めて大切です。既存対策の成功例を示すことで、メディアや行政、地域住民の意識を高め、より効果的な防災・減災施策を社会へ発信できます。
このようにフィールド調査は、自然を理解し、既存技術を検証し、新たな課題を見つけるための重要な活動なのです。
Our laboratory conducts investigations at disaster sites immediately after ground-related catastrophes, such as major earthquakes. When these events occur, not everyone involved can go on-site right away, making it all the more crucial to accurately and quantitatively record how the ground collapsed, the nature of the damage that ensued, and to what extent existing countermeasures proved effective. This documented evidence forms a fundamental basis for advancing the next generation of disaster prevention technologies.
For example, during the Kumamoto Earthquake in Japan and the 2018 Sulawesi Earthquake in Indonesia, large-scale ground flow was observed even on relatively gentle slopes—phenomena that defied conventional wisdom. Such unexpected occurrences compel us to re-examine established research, design standards, and evaluation methods for ground strength. Equally important is to investigate locations or structures that remained intact, asking why they emerged unscathed. By highlighting success stories of existing measures, we can raise awareness among the media, government agencies, and local communities, ultimately promoting more effective disaster prevention and mitigation policies.
In this way, field surveys serve as an indispensable activity for understanding natural processes, validating current engineering practices, and identifying new challenges. The firsthand information gathered on-site not only reveals the immediate causes of damage but also uncovers critical data that can drive the evolution of safer and more resilient infrastructure in the future.
