施工技術 (6)

[VI-434] Methods for Reducing of Friction Loss Caused along Anchor Unbonded Zone : Field Trials at Long Ground Anchor Execution Site

*小谷 直也¹、浅山 愛郎¹、元山 泰久²、十河 良弘² (1. 大成建設、2. 日特建設)

Keywords:Ground Anchor, Long Anchor, Friction Loss, Anchor Load, Elastic Elongation, Unbonded Length

Generally, no clear picture about mechanism or obvious countermeasure for friction loss caused along ground anchor unbonded zone has been unraveled. Thus, in order to reduce such friction loss, we conducted the field trials with 4 patterns(A,B,C & D) during construction of the ground anchors including long anchor with max. 51 meters length. From the results of pattern comparison, it’s concluded that applying of grease on strands and narrowing of spacers gap at unbonded zone are effective and that reinforcing of grout stop sealing at both ends of sheath is regarded as a better method.