Performance of surface structures subjected to subsurface soil erosion

Several geotechnical engineering structures (e.g. pavements, slabs-on-grade, footings) transfer pressure to the ground through a contact area with the supporting soil. Design of these structures usually assumes that full contact is established throughout the service life of the structure. Erosion of the subgrade soil is a common mechanism that can lead to the development of subsurface voids and consequently a contact loss between the structure and the supporting soil characterized by a void space under the structure. The performance of surface structures such as concrete pavements, slabs-on-grade, and sidewalks subjected to subsurface soil erosion is investigated experimentally and numerically in this thesis. The experiments were performed in a rigid tank holding a prism of sand with artificially created soil erosion; supporting a rigid steel plate. The surface deformation and contact pressure at the plate-soil interface were measured to quantify the effect of subsurface soil erosion on the stresses developing in the surface structure. Numerical modeling was conducted using 2D elasto-plastic finite element analysis. The model was first validated using the experimental results. Several scenarios were then considered where parameters such as the volume of soil erosion, its location, and the magnitude of the load the concrete slab is subjected to, were varied. Results of this investigation indicated that when the void space is centered under the slab-on-grade, tensile stresses developing in the structure increased as the size of the void increased causing ultimately the failure of the slab. It has also been concluded that when the void is offcentered, the supporting soil around the void space is likely to experience shear failure before excessive tensile stresses develop in the outermost fibers of the structure.

Level thesis:degree_level

masters

Grantor dc:publisher

École de technologie supérieure

Year dc:date

2008

Author dc:creator

• Menaa, Merouane

• beton, chaussee, dalle, element, erosion, experimental, fini, fissure, modelisation, performance, souterrain, structure, surface, trottoir

Language dc:language

en

Identifier

INSERT-YOUR-LIBRARY-ID-HERE148

OAI record oai:identifier

https://espace.etsmtl.ca/cgi/oai2?verb=GetRecord&metadataPrefix=oai_etdms&identifier=oai%3Aespace.etsmtl.ca%3A148