トンネル (3)

[III-276] Evaluation of ground stability based on measurement of preceding displacement

木梨 秀雄¹、*鈴木 拓也¹、渡辺 淳¹、萩野 知¹、藤岡 大輔¹、岡崎 雄一¹ (1. 大林組)

Keywords:Preceding displacement, Preceding displacement rate, critical strain, ground stability evaluation

In the case of unstable fracture zone or expansive ground, it is necessary to control large displacements on the surface and in Tunnel using appropriate excavation methods and countermeasures. For that purpose, it is important to measure the preceding displacement and evaluate the stability of the ground. As a guideline of evaluation, the shear strain and the plasticization of the ground etc. may be mentioned. Therefore, the authors have developed and applied a preceding displacement meter to more than 10 sites to evaluate the stability of the ground. In the following, we will consider the case of past preceding displacement measurement and the newly developed 2-axis preceding displacement meter.