A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Damage Evolution in Dry and Saturated Brittle Sandstone Revealed by Acoustic Characterization Under Uniaxial Compression
https://orcid.org/0000-0001-7304-3333
Abstract We present results of P-wave velocities and acoustic emission (AE) activities of a calcareous sandstone, collected from the Three Gorges Reservoir (TGR) area, under uniaxial loading to investigate the stress-induced damage evolution under both dry and deionized water saturated conditions. Chemical analyses of the sandstone-soaking water and microstructural observations of the sample were also conducted to study the chemical effects of water on the microstructure of sandstone. The results show that decline of P-wave velocity and accelerated AE activities in all samples are initiated after adequate volume dilatation has developed, yet the presence of water obviously postpones both processes to a higher stress ratio. Accumulated AE number is much less in saturated samples, a combined result of water-induced wave attenuation and water-enhanced microcracking with less fracturing energy. It is also shown that dissolution of carbonate cement in water takes place at room temperature. Both stress-induced inter and intra-grain cracking are significant in dry samples, while cracks in saturated samples mostly follow grain boundaries. Based on these results, three possible mechanisms responsible for the water-weakening effects of TGR sandstone, i.e., the Rehbinder effects, stress corrosion and pressure solution, are discussed in detail. A conceptual model involving pressure solution of carbonate cement is presented to explain the micro-structure evolution and damage process of TGR sandstone in the presence of water.
Highlights Water postpones the decline of P-wave velocity and accelerated AE activities in TGR sandstone to a higher stress ratio.Dissolution of carbonate cement in distilled water proceeds at room temperature. Cracks in saturated samples mostly follow grain boundaries.Pressure solution of carbonate cement plays an important part on the micro-structure and damage evolution of saturated TGR sandstone.
Damage Evolution in Dry and Saturated Brittle Sandstone Revealed by Acoustic Characterization Under Uniaxial Compression
https://orcid.org/0000-0001-7304-3333
Abstract We present results of P-wave velocities and acoustic emission (AE) activities of a calcareous sandstone, collected from the Three Gorges Reservoir (TGR) area, under uniaxial loading to investigate the stress-induced damage evolution under both dry and deionized water saturated conditions. Chemical analyses of the sandstone-soaking water and microstructural observations of the sample were also conducted to study the chemical effects of water on the microstructure of sandstone. The results show that decline of P-wave velocity and accelerated AE activities in all samples are initiated after adequate volume dilatation has developed, yet the presence of water obviously postpones both processes to a higher stress ratio. Accumulated AE number is much less in saturated samples, a combined result of water-induced wave attenuation and water-enhanced microcracking with less fracturing energy. It is also shown that dissolution of carbonate cement in water takes place at room temperature. Both stress-induced inter and intra-grain cracking are significant in dry samples, while cracks in saturated samples mostly follow grain boundaries. Based on these results, three possible mechanisms responsible for the water-weakening effects of TGR sandstone, i.e., the Rehbinder effects, stress corrosion and pressure solution, are discussed in detail. A conceptual model involving pressure solution of carbonate cement is presented to explain the micro-structure evolution and damage process of TGR sandstone in the presence of water.
Highlights Water postpones the decline of P-wave velocity and accelerated AE activities in TGR sandstone to a higher stress ratio.Dissolution of carbonate cement in distilled water proceeds at room temperature. Cracks in saturated samples mostly follow grain boundaries.Pressure solution of carbonate cement plays an important part on the micro-structure and damage evolution of saturated TGR sandstone.
Damage Evolution in Dry and Saturated Brittle Sandstone Revealed by Acoustic Characterization Under Uniaxial Compression
https://orcid.org/0000-0001-7304-3333
Abstract We present results of P-wave velocities and acoustic emission (AE) activities of a calcareous sandstone, collected from the Three Gorges Reservoir (TGR) area, under uniaxial loading to investigate the stress-induced damage evolution under both dry and deionized water saturated conditions. Chemical analyses of the sandstone-soaking water and microstructural observations of the sample were also conducted to study the chemical effects of water on the microstructure of sandstone. The results show that decline of P-wave velocity and accelerated AE activities in all samples are initiated after adequate volume dilatation has developed, yet the presence of water obviously postpones both processes to a higher stress ratio. Accumulated AE number is much less in saturated samples, a combined result of water-induced wave attenuation and water-enhanced microcracking with less fracturing energy. It is also shown that dissolution of carbonate cement in water takes place at room temperature. Both stress-induced inter and intra-grain cracking are significant in dry samples, while cracks in saturated samples mostly follow grain boundaries. Based on these results, three possible mechanisms responsible for the water-weakening effects of TGR sandstone, i.e., the Rehbinder effects, stress corrosion and pressure solution, are discussed in detail. A conceptual model involving pressure solution of carbonate cement is presented to explain the micro-structure evolution and damage process of TGR sandstone in the presence of water.
Highlights Water postpones the decline of P-wave velocity and accelerated AE activities in TGR sandstone to a higher stress ratio.Dissolution of carbonate cement in distilled water proceeds at room temperature. Cracks in saturated samples mostly follow grain boundaries.Pressure solution of carbonate cement plays an important part on the micro-structure and damage evolution of saturated TGR sandstone.
Damage Evolution in Dry and Saturated Brittle Sandstone Revealed by Acoustic Characterization Under Uniaxial Compression
Xie, N. (author) / Tang, H. M. (author) / Yang, J. B. (author) / Jiang, Q. H. (author)
2021
Article (Journal)
Electronic Resource
English
BKL:
38.58
Geomechanik
/
56.20
Ingenieurgeologie, Bodenmechanik
/
38.58$jGeomechanik
/
56.20$jIngenieurgeologie$jBodenmechanik
RVK:
ELIB41