Kalix Bridge: Demolition of a prestressed concrete bridge

Background

A new bridge was built in Kalix, northern Sweden, to replace an existing prestressed concrete box-girder bridge that had been in service for over 60 years. The need for replacement arose from recommendations extracted from an assessment of the old bridge’s state and capacity. In addition to the construction of the new bridge, its replacement necessitated the creation and evaluation of demolition procedure for the existing bridge. This procedure had to be carefully designed to avoid damaging the new bridge and stability-related issues but also to prevent debris from falling into the Kalix River, which is part of a Natura 2000 protected area. This project discussed various issues considered while developing the demolition strategy, including the use of bed-rock anchored tendons, intermediate support fixing at specific locations, and proper evaluation of position of the demolition equipment supported by the bridge, among others. The problem of disposing of the demolished material was also addressed.

Aim and objectives

The aim of this project is to study alternative possibilities and develop methods to carry out existing bridges demolition in an optimal way.

The objective is to develop and document demolition methods for the existing prestressed concrete bridge for the E4 over the Kalix river from 1957.

Results

The dismantling of the bridge was complicated by the fact that it is located in a Natura 2000 area, which means that no debris was allowed to pollute the river. Blasting, which is a common and cost-effective method, was therefore ruled out. Instead, a gradual demoltion of the bridge in reverse order to when it was built was chosen. One advantage was that the new bridge was only 5 m downstream of the old bridge. The new bridge could therefore be used for the transport of excavators equipped with crusher jaws that could gradually crush the concrete. The waste was then loaded into barges under the bridge.

Facts

Financer: SBUF

Timeline: Project started in 06-21 and Project ended in 12-22.

Principal Investigator: Cosmin Daescu, Lennart Elfgren, Jaime Gonzalez-Libreros, Hanna Lundin.

Partners: NCC

Dissemination

1. Daescu, C., Gonzalez-Libreros J.H., Wang, C., Elfgren, L., Sas, G., Nilsson, L., Larsson, T., Simonsson, P. (2023). Demolition of a 65-year-old box-girder prestressed concrete bridge located in Northern Sweden External link.. Life-Cycle of Structures and Infrastructure Systems - Proceedings of the 8th International Symposium on Life-Cycle Civil Engineering, IALCCE 2023,Pages 4007 - 4014
2. Daescu, C., Gonzalez-Libreros J.H., Wang, C., Elfgren, L., Sas, G. (2023). Demolition of a 65-year-old box-girder prestressed concrete bridge located in Northern Sweden External link.. EuroStruct 2023 European Association on Quality Control of Bridges and Structures: Digital Transformation in Sustainability / [ed] Alfred Strauss; Konrad Bergmeister, John Wiley & Sons, 2023, p. 229-234
3. Daescu, C., Lundin, H., Sarmiento, S., Gonzalez-Libreros J.H., Elfgren, L., Sas, G. (2023). Study of demolition strategies and preliminary plan for the case of the Kalix bridge External link.. Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability - Proceedings of the 11th International Conference on Bridge Maintenance, Safety and Management, IABMAS, Pages 2396 - 2403
4. Hanna, L. (2022). Study of demolition processes for prestressed concrete bridges: Kalix bridge External link.. Master Thesis LTU.
5. Sas, G., Gonzalez-Libreros, J., Ohlsson, U., Daescu, J., Elfgren, L., Nilsson, L., Larsson, T. (2023). Demontering av E4-bron över Kalix älv Erfarenhetsåterföring för underhåll och nybyggnad av förspända betongbroar External link.. Final report SBUF, Project No. 13939