IRSST - Institut de recherche Robert-Sauvé en santé et en sécurité du travail

Survey of shoring and shielding systems and reduction of the stand-off distance at the top of trenches


(Report R-582) The Safety Code for the construction industry imposes a stand-off distance at the top of excavations for depositing materials and for the movement of machines, which is particularly restrictive in an urban environment. The researchers wanted to know whether a pipe made of galvanized corrugated steel sheet used as temporary shoring would allow this distance to be reduced in the presence of machinery and heavy vehicles. Their report indicates that on-site and laboratory measurements have shown that this can be done safely, due to the robustness of the galvanized corrugated steel sheet pipe. They also revealed that the mechanical response of tubular shoring is complex, which raises questions about the interaction between the ground and the structure that cannot be explained by classical theories. The authors recommend continued research on the structural analysis of shoring so that a method for calculating and dimensioning these dynamic effects and this interaction can be developed.

(Report R-583) Designing shoring and shielding systems that effectively meet the needs of municipalities is a major challenge. In consulting the information supplied by the manufacturer, it is not easy to find or adapt an existing system. Several factors are involved: the diversity of the types of work, the significance of the operating and financial constraints, the complexity of the parameters of each case, etc. This study identifies and catalogues 26 prefabricated systems offered on the market and classifies them into four categories. It presents a detailed description of each, mainly indicating its geometric properties, advantages and disadvantages. The researchers also developed a grid to facilitate the selection of a shoring and shielding system that better meets the user’s requirements. The statistics included in their report provide an overview of the use of these systems in different Québec cities.

Additional Information

Type: Project
Number: 0099-4430
Status: Completed
Year of completion: 2008
  • André Lan (IRSST)
  • Denis LeBoeuf (Université Laval)
  • Omar Chaallal (École de technologie supérieure)
  • Renaud Daigle (IRSST)