Geomechanical Characterization of a Weak Sedimentary Rock Mass in a Large Embankment Dam Design

Author(s):  
Gian Luca Morelli ◽  
Ezio Baldovin
2006 ◽  
Vol 321-323 ◽  
pp. 328-331 ◽  
Author(s):  
Yong Seok Seo ◽  
Chang Yong Kim ◽  
Kwang Yeom Kim ◽  
Kyoung Mi Lee

A faulted rock usually shows the swelling behavior because of clay minerals which consist of the fault gouges. It makes rock mass unstable and threatens the safety of structures built in rock mass. This study was aimed at clarifying characteristics of physical and mechanical properties of faulted rock materials. At first, microstructures and mineralogical composition associated with faulting in the fault gouge zones were analyzed by using X-ray diffractometry (XRD) and SEM microphotographs. Physical properties of the faulted rock materials from fields were measured in the laboratory. It is well known that the mechanical properties are sensitive to the mineralogical assemblage and are affected by the shapes, distribution and preferred crystallographic orientation of the components. Material and direct shear tests were also conducted on faulted rock materials under saturated and unsaturated conditions. The mechanical results were analyzed together with the analyzed result of XRD and SEM.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Shahriyar Heidarzadeh ◽  
Ali Saeidi ◽  
Catherine Lavoie ◽  
Alain Rouleau

Abstract To conduct a successful geomechanical characterization of rock masses, an appropriate interpretation of lithological heterogeneity should be attained by considering both the geological and geomechanical data. In order to clarify the reliability and applicability of geological surveys for rock mechanics purposes, a geomechanical characterization study is conducted on the heterogeneous rock mass of Niobec Mine (Quebec, Canada), by considering the characteristics of its various identified lithological units. The results of previous field and laboratory test campaigns were used to quantify the variability associated to intact rock geomechanical parameters for the different present lithological units. The interpretation of geomechanical similarities between the lithological units resulted in determination of three main rock units (carbonatite, syenite, and carbonatite-syenite units). Geomechanical parameters of these rock units and their associated variabilities are utilized for stochastic estimation of geomechanical parameters of the heterogeneous rock mass using the Monte Carlo Simulation method. A comparison is also made between the results of probabilistic and deterministic analyses to highlight the presence of intrinsic variability associated with the heterogeneous rock mass properties. The results indicated that, for the case of Niobec Mine, the carbonatite-syenite rock unit could be considered as a valid representative of the entire rock mass geology since it offers an appropriate geomechanical approximation of all the present lithological units at the mine site, in terms of both the magnitude and dispersion of the strength and deformability parameters. Article Highlights Evaluating the reliability and applicability of geological survey outcomes for rock mechanics purposes. A geomechanical characterization study is conducted on the heterogeneous rock mass by considering the various identified rock lithotypes. The geomechanical parameters of intact units and their associated variabilities are used to stochastically estimate the geomechanical parameters of the heterogeneous rock mass by employing the Monte Carlo Simulation. A comparison is also made between the results of probabilistic and deterministic geomechanical analyses. The results indicate that, in the case of Niobec Mine, the combined syenite-carbonatite rock unit could be considered as a valid representative of the entire rock mass.


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