The weakening effect of water on the brittle failure strength of sandstone

Duda, Mandy; Renner, Jörg

doi:10.1093/gji/ggs090

Cited by 165 publications

(102 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should be noted that sample deformation is also influenced by the applied strain rate, which not only affects the stiffness of the rocks under compression, but also influences the deformation characteristics, especially for wet samples with low-permeability. According to previous research, the magnitude of the volumetric strain can be significantly reduced in the elastic compression stage under high strain rates, particularly for wet samples [12] and rocks may become more brittle under higher strain rates with unevenly distributed stress and strain values [26]. Therefore, great care was taken in this study to use the same strain rates for all the load applications According to Eberhardt et al [15], the whole process of compression can be characterized by some thresholds showing crack closure, initiation, and damage on the stress-strain curves.…”

Section: Stress-strain Curvesmentioning

confidence: 84%

“…When water enters the sample, it is first absorbed into the smallest pores which can be several nanometers due to the capillaries [30] and onto the mineral surfaces depending on the hydrophilia. Because large numbers of small pores exist in clays and the cement minerals and both are highly hydrophilic, the water is first dispersed onto their surfaces, as the clay minerals and the cementing materials are most reactive with water by absorbing, ion exchange, and swelling [12]. Therefore, the softening is quite marked.…”

Section: Discussionmentioning

confidence: 99%

“…According to previous studies, moisture reduction in rocks can result in increases in their stiffness and strength [10,11], especially for rocks with high clay contents. Although, degradations in elastic moduli are generally assumed with increases in moisture content, it has been reported that the Young's modulus of wet samples at the initial compression stage can be higher than those of dry samples because of the more pronounced pore and crack shrinkage of the dry samples [12].…”

Section: Introductionmentioning

confidence: 99%

“…The deformations or failure patterns also vary with water saturation [6]. The weakening effects of water on rocks are generally attributed to the chemical reactions between water and minerals, especially the clay-water reactions [7], pore pressure [17], reduction of friction between grains [23], the surface energy [12] and the test conditions. However, most of the experiments have been conducted on high-permeability rocks like sandstones, or only consider the totally dry and full saturation levels.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Influence of Water Saturation on the Mechanical Behaviour of Low-Permeability Reservoir Rocks

et al. 2017

View full text Add to dashboard Cite

Abstract:The influence of water on the mechanical properties of rocks has been observed by many researchers in rock engineering and laboratory tests, especially for sedimentary rocks. In order to investigate the effect of water saturation on the mechanical properties of low-permeability rocks, uniaxial compression tests were conducted on siltstone with different water contents. The effects of water on the strength, elastic moduli, crack initiation and damage thresholds were observed for different water saturation levels. It was found that 10% water saturation level caused more than half of the reductions in mechanical properties. A new approach is proposed to analyze the stress-strain relations at different stages of compression by dividing the axial and lateral stress-strain curves into five equal stress zones, where stress zones 1-5 refer to 0%-20%, 20%-40%, 40%-60%, 60%-80% and 80%-100% of the peak stress, respectively. Stress zone 2 represents the elastic range better than stress zone 3 which is at half of the peak stress. The normalized crack initiation and crack damage stress thresholds obtained from the stress-strain curves and acoustic emission activities averaged 31.5% and 83% of the peak strength respectively. Pore pressure is inferred to take part in the deformation of low-permeability siltstone samples, especially at full saturation levels. A change of failure pattern from multi-fracturing to single shear failure with the increase of water saturation level was also observed.

show abstract

Section: Stress-strain Curvesmentioning

confidence: 84%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of Water Saturation on the Mechanical Behaviour of Low-Permeability Reservoir Rocks

et al. 2017

View full text Add to dashboard Cite

show abstract

“…B. Vásárhelyi and I. Yilmaz et al studied the influence of water content on the strength and deformability of sandstone and gypsum specimens [10,11]. M. Duda and J. Renner performed triaxial compression experiments on sandstone to identify the weakening effect of water on the strength and brittle characteristics of rock [12]. The previous studies mainly focused on the strength and deformation properties of dry and saturated rock specimens and neglected the influence of varied water content on energy behavior.…”

Section: Introductionmentioning

confidence: 99%

Experimental Research on Energy Release Characteristics of Water-Bearing Sandstone Alongshore Wharf

Wang

Zhao

Zou

et al. 2017

Polish Maritime Research

View full text Add to dashboard Cite

show abstract

Mechanisms of time‐dependent deformation in porous limestone

et al. 2014

View full text Add to dashboard Cite

We performed triaxial deformation experiments on a water‐saturated porous limestone under constant strain rate and constant stress (creep) conditions. The tests were conducted at room temperature and at low effective pressures Peff=10 and Peff=20 MPa, in a regime where the rock is nominally brittle when tested at a constant strain rate of 10−5 s−1. Under these conditions and at constant stress, the phenomenon of brittle creep occurs. At Peff=10 MPa, brittle creep follows similar trends as those observed in other rock types (e.g., sandstones and granites): only small strains are accumulated before failure, and damage accumulation with increasing strain (as monitored by P wave speeds measurements during the tests) is not strongly dependent on the applied stresses. At Peff=20 MPa, brittle creep is also macroscopically observed, but when the creep strain rate is lower than ≈10−7 s−1, we observe that (1) much larger strains are accumulated, (2) less damage is accumulated with increasing strain, and (3) the deformation tends to be more compactant. These observations can be understood by considering that another deformation mechanism, different from crack growth, is active at low strain rates. We explore this possibility by constructing a deformation mechanism map that includes both subcritical crack growth and pressure solution creep processes; the increasing contribution of pressure solution creep at low strain rates is consistent with our observations.

show abstract

The weakening effect of water on the brittle failure strength of sandstone

Cited by 165 publications

References 67 publications

Influence of Water Saturation on the Mechanical Behaviour of Low-Permeability Reservoir Rocks

Influence of Water Saturation on the Mechanical Behaviour of Low-Permeability Reservoir Rocks

Experimental Research on Energy Release Characteristics of Water-Bearing Sandstone Alongshore Wharf

Mechanisms of time‐dependent deformation in porous limestone

Contact Info

Product

Resources

About