地盤と構造物の相互作用を考慮した土留め挙動の解析手法

Abstract

An estimation method of retaining structures used at deep excavation sites, such as an open-cut tunneling site, is investigated in this article. A frame analysis is widely used in Japanese practices. However, based on the field measurements, this frame analysis sometimes leads to conservative design, i.e., calculated deflections of retaining walls are greater than those measured in situ. To achieve more rational design, the authors have reviewed the frame analysis critically and proposed alternative method utilizing a simple soil-retaining wall interaction model using elastic-perfectly plastic spring to estimate the behavior of retaining walls. Some case studies of real open-cut tunneling works were carried out to check the validity of the proposed method. Calculated deflections and their modes by the proposed method can fit the measured deflections better than or similar to those by frame analysis, especially for a case of clayey soils.