Structural strengthening of concrete footings using external prestressing

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Bridge footing plays an important role in transferring loads from superstructure to the soil underneath. Its flexural, shear, and load carrying capacities are critical to the overall performance of the bridge. Bridge footings may require strengthening due to structural deficiency, or increase in traffic load. In this paper, a footing enlargement retrofit method utilizing external prestressing is proposed. For a square spread footing, the proposed strengthening system could be implemented using the following steps: (1) trimming four corners of the square footing, (2) installing circular prestressing ducts and tendons, (3) placing formwork and casting the additional concrete, and (4) stressing the prestressing strands. The composite action between the new and existing concrete parts is provided by the external circular prestressing. Compared with the dowel-splicing connections used in traditional methods, this new connection is more effective and practical, as the punching shear is the dominating mode of failure in the bridge footing. In this research, the effectiveness of the proposed method on improving the punching shear capacity of square spread footing is presented. Finite element models were built and analyzed using the commercial software Abaqus CAE. The primary investigated parameters were footing size, reinforcement ratio, and amount of prestressing strands. The results of this investigation suggest that the external circular prestressing can significantly improve the punching shear capacity of square spread footing.

Original languageEnglish (US)
Title of host publicationEASEC16 - Proceedings of the 16th East Asian-Pacific Conference on Structural Engineering and Construction, 2019
EditorsChien Ming Wang, Sritawat Kitipornchai, Vinh Dao
PublisherSpringer Science and Business Media Deutschland GmbH
Pages297-307
Number of pages11
ISBN (Print)9789811580789
DOIs
StatePublished - 2021
Event16th East Asian-Pacific Conference on Structural Engineering and Construction, 2019 - Brisbane, Australia
Duration: Dec 3 2019Dec 6 2019

Publication series

NameLecture Notes in Civil Engineering
Volume101
ISSN (Print)2366-2557
ISSN (Electronic)2366-2565

Conference

Conference16th East Asian-Pacific Conference on Structural Engineering and Construction, 2019
Country/TerritoryAustralia
CityBrisbane
Period12/3/1912/6/19

Keywords

  • External prestressing
  • Finite element model
  • Punching shear capacity
  • Spread footing

ASJC Scopus subject areas

  • Civil and Structural Engineering

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