Water absorption/dehydration by NMR and mechanical response for weakly cemented mudstones subjected to different humidity conditions

Wang, Shuai; Han, Lijun; Meng, Qinglin; Jin, Yuhao; Zhao, Weisheng

doi:10.1007/s10064-019-01629-5

Cited by 9 publications

(4 citation statements)

References 31 publications

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“…Sharma et al (2010) confirmed that the failure mode of weakly cemented sandstone during water softening is mainly due to detachment of cementitious materials. Weakly cemented soft rock has properties of low strength, poor cementation, and easy mudding in contact with water (Wang et al, 2020;Zhang et al, 2022b;Li et al, 2018). The RQD (Rock Quality Designation) and uniaxial compressive strength of weakly cemented soft rock are smaller than the common soft rock indicators in the eastern mines in the past (Zhang et al, 2022c).…”

Section: Introductionmentioning

confidence: 99%

Instability mechanism and anchoring control technology of expansive weakly cemented soft rock roadway

Zhang¹

2023

Journal of Theoretical and Applied Mechanics

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A long-term discontinuous development of the plastic zone and broken zone of weakly cemented surrounding rock is the main reason for instability of the surrounding rock of a roadway. The load-bearing support concept of "allowable deformation + releasable pressure + limited deformation" for a weakly cemented soft rock roadway is proposed, and an "allow-release-limit" support structure mechanical model with U-shaped steel as the main body is established. Anchoring control measures of "U-shaped steel + flexible material wall backfill + key parts strengthening" can solve problems of large deformation and long deformation duration of weakly cemented roadways.

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Section: Introductionmentioning

confidence: 99%

Instability mechanism and anchoring control technology of expansive weakly cemented soft rock roadway

Zhang¹

2023

Journal of Theoretical and Applied Mechanics

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“…Drying process caused by high temperature between wetting events intensifies physical disintegration (Cantón et al, 2001) by producing strong thermal stress which increases rock breakdown (Hall and Hall, 1991;Hale and Shakoor, 2003;Aly et al, 2015) and promotes water-gas phase transformation generating stress formation through volume increase (Hale and Shakoor, 2003). Colback and Wiid (1965) also demonstrated that changes in the relative humidity or partial pressure of water in the pores can lower rock strength dramatically, while Wang et al (2019b) indicated that water absorption and dehydration alter rock structures and affect mechanical properties due to variation of water content altering bonding strength between particles.…”

Section: Introductionmentioning

confidence: 99%

“…Disintegration rate could be correlated to the pore structure parameters. Sediments with clay minerals as main constituents and pore structure dominated by mesopores (2～ 50 nm) have a large specific surface area which is positively related to water absorption (Lu et al, 2015;Wang et al, 2019aWang et al, , 2019b. Pore size distribution of mudstones is primarily controlled by grain size, and generally, pore size and permeability decrease as grain size decreases (Yang and Aplin, 2010).…”

Section: Introductionmentioning

confidence: 99%

The Influences of Climatic and Lithological Factors on Weathering of Sediments in Humid Badland Areas

et al. 2022

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Climate variables including temperature, rainfall intensity, rainfall acidity, and lithological properties are among the most important factors affecting rock weathering. However, the relative contribution of these four factors on rock weathering, especially on chemical weathering, is still unclear. In this study, we carried out a series of weathering-leaching rainfall simulations on four types of badland sediments under controlled conditions of two levels of temperature, rainfall intensity, and rainfall acidity based on the real field data from representative weather scenarios. The main objectives are 1) to explore the progressive change of sample surface and leachate characteristics and 2) to reveal the independent effects of temperature, rainfall intensity, rainfall acidity, and lithology and their relative contribution as well, on both mechanical and chemical weathering. Qualitative analysis on crack development and fragmentation of sample surface and quantitative analysis on the leachate volume, pH, electrical conductivity, and total cation and anion releases of sample leachate together demonstrated that for the investigated sediments, under the conditions of temperature, intensity, and acidity of rain that can be achieved in nature, high drying temperature obviously increases mechanical disintegration by promoting the rate and magnitude of moisture variations (wetting–drying alterations), while high rainfall intensity and acid rain have no obvious effect. Impact and importance of the drying process caused by high temperature between wetting events need more attention, rather than high rainfall intensity. Low temperature, high rainfall intensity, and acid rain contributing more hydrogen ions required for cation exchanges, rock type with more soluble minerals, all promote chemical weathering, and the influence of climatic and lithological factors on chemical weathering decreases in the following order: mineral composition> rainfall intensity > temperature > rainfall acidity. Climatic variations on temperature can modify weathering processes and in that way conditioned hydro-geomorphological processes in badland areas. Such changes should be considered for direct and indirect implications on badland dynamics.

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“…Li et al experimented to study on the softening characteristics of mudstone in relation to moisture content [15] and showed that moisture content has a significant effect on shear properties reduction of mudstone and stress concentration is negatively correlated with moisture content. Wang investigated the pore structure and water imbibition behaviour through the mercury injection experiment [16] and proposed that the expansion deformation can be controlled by strengthening the lateral restraint. Kovalenko studied the failure of rock under dynamic loading and suggested an algorithm for calculating the failure zones that allows the geometric position and size of the zone to be determined and sheds light on the mechanism by which failure appears and develops over time [17].…”

Section: Introductionmentioning

confidence: 99%

Influence of Moisture Content on the Structural Characteristics of Argillaceous Weakly Consolidated Rock Caused by Dynamic Loading in the Coal Mine

Meng

Han

Zhu

et al. 2021

Shock and Vibration

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The argillaceous weakly consolidated rock is a kind of soft rock that will bring great difficulties in the construction process. Specimens of such rock under different moisture contents are taken as the research object. By the Hopkinson pressure bar test (SHPB), the structural and mechanical characteristics of the rock under dynamic impact are analysed. With increasing moisture content, the transmitted wave amplitude decreases gradually, which indicates that the higher the moisture content of the rock is, the easier it is to deform under dynamic impact and the greater its plasticity. The boundary between plastic failure and brittle failure is 10% moisture content. Through a mercury injection test, the porosity variation is analysed. The porosity of the rock decreases with increasing moisture content after the same dynamic impact. The porosity curve can be roughly divided into two sections with a moisture content of 15% as the boundary. Based on a uniaxial compression test, the elastic modulus, peak strength, and residual strength of specimens after dynamic impact are analysed, and the mechanical properties of the rock are revealed. Its mechanical properties can be divided into three sections with a moisture content of 9.18% and 15.19%, and each section has obvious differences.

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Water absorption/dehydration by NMR and mechanical response for weakly cemented mudstones subjected to different humidity conditions

Cited by 9 publications

References 31 publications

Instability mechanism and anchoring control technology of expansive weakly cemented soft rock roadway

Instability mechanism and anchoring control technology of expansive weakly cemented soft rock roadway

The Influences of Climatic and Lithological Factors on Weathering of Sediments in Humid Badland Areas

Influence of Moisture Content on the Structural Characteristics of Argillaceous Weakly Consolidated Rock Caused by Dynamic Loading in the Coal Mine

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