Developing a high capacity direct shear apparatus for the large scale laboratory testing of rock joints

Moradian, Zabihallah; Gravel, C.; Fathi, Ali; Ballivy, G.; Rivard, Patrice; Quirion, Marco

doi:10.1201/b15683-52

Cited by 5 publications

(6 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ten (10) studied concrete‐rock contacts are described in Table 1. They consist of six (6) small core samples extracted from existing dam‐rock interfaces with diameters

D_{s}

varying from 83 to 145 mm, 6,23,24 and four (4) larger rectangular samples with side lengths

L_{s}

comprised between 320 and 492 mm 21,40 . The six core samples were drilled at the sites of three existing gravity dams in Quebec, Canada, denoted hereafter as dams D1, D2, and D3, as shown in Figure 1A.…”

Section: Contact Specimens and Direct Shear Testingmentioning

confidence: 99%

“…In what follows,

D_{\max}

denotes the maximum dimension in the shearing direction of the concrete‐rock contacts which corresponds to the diameter

D_{s}

and the length

L_{s}

for the core and rectangular samples, respectively. All the samples were shear‐tested at the Rock Mechanics Laboratory of the Université de Sherbrooke 6,21,23,24,40 …”

Section: Contact Specimens and Direct Shear Testingmentioning

confidence: 99%

“…The direct shear tests of the small to larger contact interfaces were conducted by Rousseau , 23 Moradian et al. , 40 and Gravel et al. 21 at the Université de Sherbrooke and are briefly reviewed hereafter: The six small concrete‐rock contact specimens were tested using a direct shear apparatus under controlled displacement mode 23,24 .…”

Section: Contact Specimens and Direct Shear Testingmentioning

confidence: 99%

“…The silicone replica of the larger rectangular rock surface LCR3 of

444 \times 444

mm was brought to the laboratory at the Université de Sherbrooke to fabricate the corresponding contact specimen using a specific mortar mix prepared to have similar mechanical and physical properties than the granite of the contact surface LCR3 40 . The mortar was then cast on the silicone replica and the corresponding concrete‐rock interface was obtained by pouring concrete on the replica while ensuring fully unbonded and perfectly matched conditions along the contact 40 . The contact specimen LCR3 was shear tested using a large capacity direct shear apparatus under controlled displacement mode 40 .…”

Section: Contact Specimens and Direct Shear Testingmentioning

confidence: 99%

See 3 more Smart Citations

Experimental, analytical, and finite element assessment of the shear strength of concrete‐rock interfaces at different scales

Renaud

Bouaanani

Miquel

2021

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

This paper presents an original analytical approach to assess the shear strength of concrete‐rock interfaces while accounting for the effects of scale, roughness and matching conditions. The technique proposed is based on experimental data obtained from small core samples extracted from existing dam sites, with diameters varying from 83 to 145 mm, and larger rectangular samples with side lengths comprised between 320 and 492 mm. The predictions of the analytical formulation are validated against results of direct shear tests, as well as 3D nonlinear finite element simulations. Sensitivity analyses are conducted to evaluate the influence of roughness and matching conditions on the shear behavior of concrete‐rock contacts at different scales. The main results show that: (i) roughness inhomogeneity is one of the main causes of scale effects on the shear strength of concrete‐rock interfaces; (ii) contact geometries proportional in both length and height are expected to present quite similar shear strengths; and (iii) geometry matching conditions must be accounted for as they might be the source of scale effects affecting the evaluation of the shear strength at concrete‐rock interfaces. New equations are also proposed to suggest values of apparent cohesion and friction angle for concrete‐rock contacts.

show abstract

“…The ten (10) studied concrete‐rock contacts are described in Table 1. They consist of six (6) small core samples extracted from existing dam‐rock interfaces with diameters

D_{s}

varying from 83 to 145 mm, 6,23,24 and four (4) larger rectangular samples with side lengths

L_{s}

Section: Contact Specimens and Direct Shear Testingmentioning

confidence: 99%

“…In what follows,

D_{\max}

denotes the maximum dimension in the shearing direction of the concrete‐rock contacts which corresponds to the diameter

D_{s}

and the length

L_{s}

for the core and rectangular samples, respectively. All the samples were shear‐tested at the Rock Mechanics Laboratory of the Université de Sherbrooke 6,21,23,24,40 …”

Section: Contact Specimens and Direct Shear Testingmentioning

confidence: 99%

Section: Contact Specimens and Direct Shear Testingmentioning

confidence: 99%

“…The silicone replica of the larger rectangular rock surface LCR3 of

444 \times 444

Section: Contact Specimens and Direct Shear Testingmentioning

confidence: 99%

See 2 more Smart Citations

Experimental, analytical, and finite element assessment of the shear strength of concrete‐rock interfaces at different scales

Renaud

Bouaanani

Miquel

2021

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

show abstract

“…Herein, tests using a high stiffness dummy, i.e., a steel specimen, are proposed to enable calibration of test systems. However, in the literature, the information is limited about how to carry out calibrations and whether calibrations have been employed to the test systems (Barla et al 2010;Liu et al 2017;Haberfield and Szymakowski 2003;Moradian et al 2013;Rao et al 2009;Hans and Boulon 2003). In work by Jiang et al (2004), graphs of the normal stress versus normal displacement from CNS tests were presented.…”

Section: Introductionmentioning

confidence: 99%

An Approach to Compensate for the Influence of the System Normal Stiffness in CNS Direct Shear Tests

Larsson

Flansbjer

2020

Rock Mech Rock Eng

View full text Add to dashboard Cite

Applying accurate normal load to a specimen in direct shear tests under constant normal stiffness (CNS) is of importance for the quality of the resulting data, which in turn influences the conclusions. However, deficiencies in the test system give rise to a normal stiffness, here designated as system normal stiffness, which results in deviations between the intended and actual applied normal loads. Aiming to reduce these deviations, this paper presents the effective normal stiffness approach applicable to closed-loop control systems. Validation through direct shear tests indicates a clear influence of the system normal stiffness on the applied normal load (13% for the test system used in this work). The ability of the approach to compensate for this influence is confirmed herein. Moreover, it is demonstrated that the differences between the measured and the nominal normal displacements are established by the normal load increment divided by the system normal stiffness. This further demonstrates the existence of the system normal stiffness. To employ the effective normal stiffness approach, the intended normal stiffness (user defined) and the system normal stiffness must be known. The latter is determined from a calibration curve based on normal loading tests using a stiff test dummy. Finally, a procedure is presented to estimate errors originating from the application of an approximate representation of the system normal stiffness. The approach is shown to effectively reduce the deviations between intended normal loads and the actual applied normal loads.

show abstract

Contribution of 3D Roughness Along Concrete-Rock Interface to the Sliding Stability of Concrete Gravity Dams

Saichi,

Bouaanani

2024

Geotech Geol Eng

View full text Add to dashboard Cite

Developing a high capacity direct shear apparatus for the large scale laboratory testing of rock joints

Cited by 5 publications

References 1 publication

Experimental, analytical, and finite element assessment of the shear strength of concrete‐rock interfaces at different scales

Experimental, analytical, and finite element assessment of the shear strength of concrete‐rock interfaces at different scales

An Approach to Compensate for the Influence of the System Normal Stiffness in CNS Direct Shear Tests

Contribution of 3D Roughness Along Concrete-Rock Interface to the Sliding Stability of Concrete Gravity Dams

Contact Info

Product

Resources

About