Buoyancy effects on structures : a case study on the controlled lowering of a raised underground garage

Čas, Bojan (author), Šporin, Jurij (author)

In recent decades, the height of buildings and the number of basement floors has increased, especially in valuable urban locations. With the development of cities and the infrastructure essential for their operation, extensive underground construction is being carried out, including utility lines, subway tunnels etc. Water accumulation, fluctuating or high groundwater levels in the area of underground structures, due to various reasons, might cause structures, forming a closed volume, to move upwards. The excessive buoyancy problem, which arises, when necessary, precautions are not taken, is often overlooked by engineers. The negative effects of buoyancy on structures typically manifest as uplifts, settlements, or rotations. The state of structures damaged by excessive buoyancy must be thoroughly investigated to determine whether rehabilitation is possible or if the underground structure needs to be completely removed due to the infeasibility or cost inefficiency of its possible rehabilitation. This paper presents a methodology for addressing the state of structures affected by excessive buoyancy to find a suitable technological rehabilitation solution, supported by a case study. It demonstrates how inadequate design and execution of a single detail of a three-story underground garage resulted in its sudden elevation due to buoyancy. Through a thorough examination of the site, the state of the raised structure, the original project documentation, and basic safety check of anti-floating stability, rehabilitation procedure for the successful and controlled lowering of the underground garage was developed.

• Language: English
• Keywords: civil engineering, underground garage, reinforced concrete, buoyancy, anti-floating stability, uplift, cracks, groundwater inflow, controlled lowering
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FGG - Faculty of Civil and Geodetic Engineering; NTF - Faculty of Natural Sciences and Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 13 str.
• Numbering: Vol. 71, art. 108121
• PID: 20.500.12556/RUL-166476
• UDC: 69
• ISSN on article: 2352-0124
• DOI: 10.1016/j.istruc.2024.108121
• COBISS.SI-ID: 221926659
• Publication date in RUL: 14.01.2025

Record is a part of a journal

• Title: Structures
• Publisher: Elsevier
• ISSN: 2352-0124
• COBISS.SI-ID: 525573145

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: gradbeništvo, podzemna garaža, armirani beton, vzgon, stabilnost proti vzgonu, dvig, razpoke, vtekanje podzemnih voda, kontrolirano spuščanje

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0260
• Name: Mehanika konstrukcij