Experimental Study on Seismic Retrofitting Technology that Complements Existing Pile Foundations with Soil-Cement Columns Made with Cementitious Solidification Material

既設杭基礎にセメント系固化材による地盤改良体を併設する耐震補強技術に関する実験的検討

Inadequate seismic performance of foundations during an earthquake causes excessive response displacement of the superstructure, which may degrade the functions of the entire structure. Thus, like the seismic reinforcement of superstructures and substructures, reinforcement measures are considered necessary for the existing foundations of structures that could not be provided with the required seismic performance, including liquefaction countermeasures. Consequently, as a reasonable seismic retrofitting technology for foundations in soft ground or liquefied ground, composite piles that provide soil-cement columns made with cementitious solidification material around pile foundations were researched and developed. Composite piles differ from conventional foundation seismic reinforcement methods that integrate reinforcement piles, reinforcement material or soil-cement columns with the substructure in that they represent a technology that aims to secure seismic performance of existing pile foundations solely through the reaction force of soil densification columns, and they are considered advantageous in terms of executability and cost. A series of large-scale experiments on the practical application of composite piles was conducted and findings on their seismic performance centering on the energy absorption effect are reported.地震時において，基礎の耐震性能が不十分な場合には上部工の応答変形も過大となり，構造物全体の機能を損なう可能性がある。そのため，上部工および下部工の耐震補強と同様に，液状化対策も含め所要の耐震性能を確保していない既設構造物基礎に対しても補強対策を講じる必要があると考えられる。そこで，軟弱地盤および液状化地盤における合理的な基礎の耐震補強技術として，杭基礎周辺にセメント系固化材による地盤改良体を併設するコンポジットパイルを研究開発した。コンポジットパイルは，増し杭や補強材・地盤改良体を下部工と一体化させる従来の基礎の耐震補強工法とは異なり，あくまでも固化改良体の反力効果に期待し既設杭基礎の耐震性能の確保を図る技術であり，施工性・コスト面でも有用と考えられる。以下に，コンポジットパイルの実用化に向け，一連の大規模模型実験を行い，エネルギー吸収効果を主体に耐震性能について整理した。

• Record URL:
  https://doi.org/10.3151/coj.51.499
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=Experimental+Study+on+Seismic+Retrofitting+Technology+that+Complements+Existing+Pile+Foundations+with+Soil-Cement+Columns+Made+with+Cementitious+Solidification+Material&author=K.+Tomisawa&author=T.+Maki&author=T.+Watanabe&author=T.+Sasaya&publication_year=2013
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03871061
• Authors:
  • Tomisawa, K
  • Maki, T
  • Watanabe, T
  • Sasaya, T
• Publication Date: 2013

Language

• English
• Japanese

Media Info

• Media Type: Web
• Features: References;
• Pagination: pp 499-506
• Serial:
  • Concrete Journal
  • Volume: 51
  • Issue Number: 6
  • Publisher: Japan Concrete Institute
  • ISSN: 0387-1061
  • EISSN: 2186-2753
  • Serial URL: https://www.jstage.jst.go.jp/browse/coj

Subject/Index Terms

• TRT Terms: Earthquake resistant design; Energy absorption; Pile foundations; Retrofitting; Soft soils; Soil cement; Substructures; Superstructures
• Subject Areas: Bridges and other structures; Geotechnology; Highways; I24: Design of Bridges and Retaining Walls; I42: Soil Mechanics;

Filing Info

• Accession Number: 01542278
• Record Type: Publication
• Source Agency: Japan Science and Technology Agency (JST)
• Files: TRIS, JSTAGE
• Created Date: Oct 29 2014 11:26AM