A Compilation of the Geo-Mechanical Properties of Rocks in Southern Ontario and the Neighbouring Regions

Hayder Mohammed Salim Al-Maamori,Silvana Micic,Mohamed Hesham El Naggar

doi:10.4236/ojg.2014.45017

Abstract

The available measurements of the geo-mechanical properties of rocks in Southern Ontario and the neighbouring regions (New York, Ohio, Michigan, Indiana, Illinois, Wisconsin, and Minnesota) are summarized and presented. These measurements were compiled from available published data in the relevant literature and also from data that were collected from major underground projects in these regions. The compiled data are presented in three categories: measured in-situ stresses in different rock formations; calculated strength, stiffness and deformation including time-dependent deformation properties; and the measured dynamic properties of intact rock specimens from different rock formations in Southern Ontario and the neighbouring regions. The data presented in this paper can be used as a resource for preliminary evaluation of the geomechanical properties of the rocks in these regions. The presented geo-mechanical properties were generally obtained from in-situ measurements and from laboratory tests that were conducted on intact rock specimens from freshly excavated rock samples. Moreover, the time-dependent deformation properties of rocks in these regions were obtained from laboratory tests that were performed on intact rock specimens submerged in water. However, the influence of drilling fluids such as bentonite slurry and synthetic polymers solution, on the geo-mechanical properties of rocks is not evident and needs to be investigated.

Highlights

The first step in the design process of underground structures in rocks is to define the strength and deformation parameters of the rock unit in addition to the initial in-situ stresses that exist at a specific depth in the hosting rock unit
The presented data were compiled from sites where different measuring techniques were used to evaluate the in-situ stresses at variable depths and diversity of rock formations in Southern Ontario and the surrounding regions (i.e. New York, Ohio, Michigan, Indiana, Illinois, Wisconsin, and Minnesota)
This attempt was followed by numerous studies that resulted in developing several methods to measure the in-situ stresses in different locations all over the world, many of which were in Southern Ontario

Summary

In-Situ Horizontal Stresses

Lo [1] analyzed natural geological features, such as: faulting; folding and buckling or pop-up of surface rock strata; distress in shallow and deep excavation, such as heaves in the Dufferin quarry in Milton; jamming of wheel pit, bending and buckling of steel beams structures of hydro-electric power plants; and crushing and spalling of arch and floor heave of the hydro tunnels in the Niagara area and Chippawa Canal in Ontario Based on these analyses, it was suggested by Lo [1] that these observations were evidence of high in-situ horizontal stresses that resulted from the current movement of continental drift according to tectonic theory, and not due to the past overburden load during glaciation ages [1]. These high in-situ horizontal stresses, after their relief, might be of significant influence on the time-dependent deformation characteristics of these rocks, which in turn might cause serious damages to the constructed underground structures

Intact Rock Strength and Stiffness Properties

Intact Rock Time-Dependent Deformation Properties

Dynamic Properties of Rocks

Summary and Conclusions

Findings

Method Used