Vol. 22, No. 4, pp. 432-444 (2026)
PRELIMINARY STUDY ON LEANING COLUMN EFFECT CAUSING COLLAPSE OF
TEMPORARY SUPPORTS DURING GROUTING IN TAIWAN
Jui-Lin Peng 1, *, Chung-Sheng Wang 2, Jake Lok Yan Chan 3 and Wai-Fah Chen 4
1 Department of Civil and Construction Engineering, National Yunlin University of Science and Technology, Taiwan
2 Department of Civil and Construction Engineering, National Yunlin University of Science and Technology, Taiwan
3 NIDA Technology Company Limited, Science Park, Hong Kong, China
4 Department of Civil and Environmental Engineering, University of Hawaii, & Member of National Academy of Engineering
*(Corresponding author: E-mail:This email address is being protected from spambots. You need JavaScript enabled to view it.)
Received: 1 May 2025; Revised: 1 May 2025; Accepted: 5 May 2026
DOI:10.18057/IJASC.2026.22.4.7
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ABSTRACT
In reinforced concrete structures, temporary supports frequently fail during slab grouting instead of after completion. This indicates that the initial design strength of the temporary support is greater than the actual weight of the newly grouted concrete. This study investigates the failure mechanism of temporary support collapses during concrete grouting, based on LeMessurier's theory of the leaning column effect and previous research by Peng et al. on the load-bearing capacity and the leaning column effect in single-story, double-story, and combined scaffold temporary supports. The findings indicate that the collapse mechanism in these temporary supports during concrete grouting is primarily driven by the leaning column effect, which significantly reduces the critical loads of the overall structural system. The leaning column will induce the leaning column effect in the compression structural system, thereby significantly reducing the critical load of the overall structural system. This study examines the three types of temporary supports and explains how the failure mechanism of the leaning column effect influences the reduction of critical loads on the overall structures. Moreover, this study collected actual collapse instances of the three previously mentioned types of temporary supports to illustrate how the failure mechanism associated with the leaning column effect results in the collapse of the temporary support during the grouting process. Proposals for improving assemblies of three temporary supports were also made. When designing temporary supports, it’s essential to change the unrestrained boundary condition of the structural system to a restrained one to eliminate the leaning column effect.
KEYWORDS
Buckling, Leaning-column, Scaffold, Shore
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