Elucidation of unsaturated soil behavior in desiccation process and prevention of damage of geo-relics caused by desiccation

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K13827
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 22030:Geotechnical engineering-related
• Research Institution: Kyoto University
• Principal Investigator: Sawada Mai 京都大学, 工学研究科, 助教 (50781077)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 不飽和土 / 乾燥亀裂 / 引張応力 / 内部応力 / 水分熱移動 / 蒸発 / 潜熱 / 文化財

Outline of Final Research Achievements

This study aims 1) to evaluate water transfer in desiccation process, 2) to measure volume change and tensile stress due to desiccation, and 3) to develop countermeasures for desiccation considering water transfer, deformation and stress. The major achievements are 1) development of numerical analysis of water and heat transfer of soil during evaporation, and clarification of its problems via the comparison with experimental results, 2) development and verification of a method for measuring internal stress evolving in desiccation cracking process, and 3) numerical simulation of the internal stress measured with the proposed experiment using a non-liner elastic model which uses skeleton stress as a stress variable.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

土構造物の損傷は，湿潤過程と乾燥過程の両方で生じるが，乾燥過程の研究事例は希少である。今後の気候変動下に備え，乾燥過程での土の体積変化および引張挙動に関する深い理解が必要である。また，屋内に保存されている古墳等の歴史的遺構や，断層等の災害遺構においては，乾燥による損傷が顕在化しており，良好な保全環境の整備が喫緊の課題になっている。本研究で取り組んだ，地盤の水分熱移動の定量的評価および乾燥亀裂発生過程での引張応力の実測とモデル化，はこれらの課題解決に役立つ成果である。