Assessment of engineering behaviour of an intensely weathered swelling mudstone under full range of seasonal variation and the relationships among measured parameters

Zeng, Zhixiong; Kong, Lingwei; Wang, Min; Sayem, Hossain Md.

doi:10.1139/cgj-2017-0582

Cited by 41 publications

(14 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is easily recognizable that the decreasing extent of cohesion of GRS is much higher than that of internal friction angle due to AGF effects. This phenomenon can be ascribed to the cracking behavior of GRS due to negative temperatures that mainly weaken the original cohesive force of clay aggregates rather than the friction force between the grains (Zeng et al, 2018).…”

Section: Stress-strain Behavior and Shear Strengthmentioning

confidence: 99%

Artificial Ground Freezing Impact on Shear Strength and Microstructure of Granite Residual Soil Under an Extremely Low Temperature

Zhang

Kong

et al. 2021

Front. Earth Sci.

Self Cite

View full text Add to dashboard Cite

The Artificial Ground Freezing (AGF) method, which is widely used in tunnel excavations, significantly affects the properties of geotechnical materials in frozen walls under extremely low temperatures. In order to simulate the AGF process, the freezing treatment with a temperature of −30°C and thawing treatment temperature of 25°C were performed on natural specimens of granite residual soil (GRS). Subsequently, triaxial (TRX) tests were conducted to evaluate mechanical properties and Nuclear Magnetic Resonance Image (NMRI) tests were applied to detect pore distributions of GRS. To clarify variations of microstructure after freezing-thawing, the relaxation time (T2) distribution curves and T2-weighted images from NMRI results were thoroughly analyzed from the perspective of quantization and visualization. Results show that the shear strength as well as the cohesion of GRS are reduced sharply by the AGF process, while the internal friction angle decreases gently. The pore size distribution (PSD) converted from the T2 curve is constituted of two different peaks, corresponding to micro-pores with diameters from 0.1 to 10 µm and macro-pores with diameters from 10 to 1,000 µm. Under the AGF impact, the expansion in macro-pores and shrinkage in micro-pores simultaneously exist in the specimen, which was verified from a visualized perspective by T2-weighted images. The frost heaving damage on shear strength is attributed to the microstructural disturbance caused by the presence of large-scale pores and uneven deformations in GRS, which is subjected to the AGF impact under an extremely low temperature.

show abstract

Section: Stress-strain Behavior and Shear Strengthmentioning

confidence: 99%

Artificial Ground Freezing Impact on Shear Strength and Microstructure of Granite Residual Soil Under an Extremely Low Temperature

Zhang

Kong

et al. 2021

Front. Earth Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…e above studies play an important role in the mechanism investigation of foundation soil below the canals under cyclic actions of wet-dry or freeze-thaw [26][27][28]. However, studies related to a typical canal in Xinjiang showed that the expansive mudstone below the canals experienced a wet-dry-freeze-thaw process throughout the year [29][30][31], as shown in Figure 2. e volume changes and mechanical properties of expansive mudstone below the canals in Xinjiang are very scarce in the literature.…”

Section: Introductionmentioning

confidence: 99%

Volume Changes and Mechanical Properties of Expansive Mudstone below Canals under Wet‐Dry/Wet‐Dry‐Freeze‐Thaw Cycles

Zhu

Huang

Song

et al. 2021

Advances in Civil Engineering

View full text Add to dashboard Cite

The complex environment in northern China is the main reason for degradation of expansive mudstone below the canals, which resulted in instability and damage of canal slopes. In this study, a serial of laboratory tests was conducted to explore the volume changes and mechanical behaviors of expansive mudstone below the canals in Xinjiang. The experimental program includes wet-dry (WD) and wet-dry-freeze-thaw (WDFT) tests, volume measurement, and unconfined compression tests. The test results show that during the WD cycles, the volume changes of expansive mudstones with a higher dry range would be more significant. The freeze-thaw process in the WDFT cycles resulted in a decrease of volume change ranges when the expansive mudstones had a relatively smaller dry range and a slight increase of volume change ranges when the expansive mudstones had a relatively larger dry range. In the meantime, the stress-strain relationships of expansive mudstones with different dry ranges all presented strain softening under the cycles of WD or WDFT. The first cycle resulted in a significant decrease of failure strength. After seven WD/WDFT cycles, the failure strength of expansive mudstones with different dry ranges decreased by 37.2%∼59.1%. In addition, the freeze-thaw process in the WDFT cycles promoted the softening of the stress-strain relationships and aggravated the failure strength attenuation of expansive mudstones. Through this study, we expect to provide a preliminary basis for the construction and maintenance of expansive mudstone canals in Xinjiang.

show abstract

“…To obtain the deformation and shear strength of a weathering rock, researchers have attempted to develop some new apparatus and methods (Sun et al, 2004;Duan et al, 2017;Vlastelica et al, 2017;Chen and Lin, 2019). Treatments like freezing-thawing cycles, drying-wetting cycles, and coolingheating cycles were applied on various rocks, including granite, marl, and mudstone, to simulate the weathering process (Özbek, 1998;Miščević and Vlastelica, 2010;Li et al, 2011;Zeng et al, 2018). These laboratory experiments showed that the compressive strength, the shear strength, and the tensile strength generally decrease after the weathering treatments, mainly owing to the generation of intergranular microcracks at the interfaces between the different minerals.…”

Section: Introductionmentioning

confidence: 99%

An Experimental and Numerical Study of Diorite-Porphyrites With Different Weathered Degree in the Direct Shear Test

Fan

Sun

et al. 2020

Front. Earth Sci.

View full text Add to dashboard Cite

There are many well-developed weathered diorite-porphyrites, except main rocks, in the Jurong pumped storage power station of Jiangsu Province, China. Due to different geological environments, diorite-porphyrites emerged by invading faults and can alter from weakly weathered to strongly weathered in less than half a year, which directly affected the safety and stability of hydraulic structures. Therefore, it is important to study the mechanical properties of diorite-porphyrites with different degrees of weathering. The main purpose of this paper is to investigate the effects of the different degrees of weathering on the shear behavior and the mechanical properties of diorite-porphyrites. Experimental and numerical direct shear tests were performed under normal stresses of 0.54, 0.77, 1.53, and 2.30 MPa on strongly weathered, moderately weathered, and weakly weathered samples, respectively. The test results show that with the increase of the degree of weathering, the chemical composition changed; the cohesion and the internal friction angle both decreased. Crack initiation, propagation, and coalescence were all observed with the numerical simulations using two-dimensional particle flow code (PFC 2D). The numerical results are in good agreement with the experimental results, and this numerical approach can reproduce the shear behavior of the weathered diorite-porphyrites under different shear conditions. Based on the gradient of the prepeak stage, the peak stress, and the residual stress, the shear stress-displacement curves can be categorized into three types: type A (mostly for the strongly weathered diorite-porphyrite), type B (mostly for the moderately weathered diorite-porphyrite), and type C (mostly for the weakly weathered diorite-porphyrite). A set of microparameters that can properly simulate the weathered diorite-porphyrites in PFC 2D was proposed, which can be applied in the engineering simulation for further analysis.

show abstract

Assessment of engineering behaviour of an intensely weathered swelling mudstone under full range of seasonal variation and the relationships among measured parameters

Cited by 41 publications

References 32 publications

Artificial Ground Freezing Impact on Shear Strength and Microstructure of Granite Residual Soil Under an Extremely Low Temperature

Artificial Ground Freezing Impact on Shear Strength and Microstructure of Granite Residual Soil Under an Extremely Low Temperature

Volume Changes and Mechanical Properties of Expansive Mudstone below Canals under Wet‐Dry/Wet‐Dry‐Freeze‐Thaw Cycles

An Experimental and Numerical Study of Diorite-Porphyrites With Different Weathered Degree in the Direct Shear Test

Contact Info

Product

Resources

About