2019 Volume 75 Issue 1 Pages 76-89
Aging and other such factors may cause ground anchors (hereinafter anchors) to deteriorate. When considering the construction of additional anchors, stability studies carried out at the initial construction of anchors will be valuable information. However, some early anchors have been in service for more than 40 years, and information available for designing and constructing countermeasures might be insufficient. In addition, the slide plane of a slope face where deforming has settled may be hard to estimate even after conducting boring explorations or movement observations. Furthermore, only the anchor head can be confirmed at the site since the most part of anchors is embedded in the ground. In such cases, setting the supporting strength, which decide the number of anchors to be installed, will be difficult when designing the additional anchors. This study proposes estimation method of slip surface for evaluation deterrent force of existing anchors from information gained by examining the appearance of the anchor head and other observations.