Influence Mechanism of Different Flow Patterns on the Softening of Red-Bed Soft Rock

Liu, Zhen; He, Xinfu; Zhou, Cuiying

doi:10.3390/jmse7050155

Cited by 17 publications

(12 citation statements)

References 14 publications

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“…With the development of testing technology and testing methods, more and more scholars begin to pay attention to the influence of water-rock interaction on rock properties after rainwater enters into the rock mass. Liu et al [16] discussed two typical flow patterns on the softening of red sandstone and pointed out that dynamic water-rock interactions have a great effect on rock softening and breaking. Xu et al [17,18] studied the effect of periodic water circulation on rock mass by P-Wave Velocity and found that the water-rock interaction changed the porosity of the rock pores and then affected its mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

Study on the Influence of Water–Rock Interaction on the Stability of Schist Slope

et al. 2020

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(1) The studies on the influence of rainfall on slope stability mainly focus on rainfall characteristics and the variation of strength parameters. Few studies pay attention to the micro structure changes of rock mass under long-term rainfall conditions, and the influence of failure mode. (2) Based on nuclear magnetic resonance (NMR) and electron microscopic imaging (Emmi) technology, the micro structure changes and macro deformation characteristics of the schist, under long-term immersion in different liquids are analyzed. (3) After soaking in the deionized water, the uniaxial compression strength of the intact specimen is slightly lower than that of the untreated specimens, but the test process in the elastic compression stage is considerably prolonged, and the failure modes show both shear and slip at the same time. While after soaking in acid solution, the fracture of rock samples with initial cracks can be obviously reduced and healed, which is consistent with the change of micro pore structure. The uniaxial strength and modulus of the intact samples are significantly lower, and only slip failure mode occurred. (4) It shows that water–rock interaction is an important factor influencing the stability of slope besides the external rainfall force, which affects the structural characteristics and mechanical properties of rock.

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Section: Introductionmentioning

confidence: 99%

Study on the Influence of Water–Rock Interaction on the Stability of Schist Slope

et al. 2020

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“…According to our preliminary research, the laboratory experimental study on the influences of different flow patterns on the softening of red-bed sandstone shows that different flow patterns have almost the same effect on electron surface migration and rock failure. As the flow of water increased, the alkalinity of the circulating solution became stronger, the speed of stabilization of the ion concentration became faster, the development of the microscopic structure of the corresponding rock became higher, and the decrease in mechanical strength became greater [4]. In view of previous studies on the influence of flow patterns on rock failure, this paper will no longer focus on this aspect.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…As a kind of special soft rock (that is, the rock whose strength characteristics and engineering forces conform to the parameters described in the literatures [1,2]) which is easy to soften and collapse in the event of water, it is often encountered in major engineering construction efforts, such as the Gezhouba hydraulic engineering project, the Three Gorges Reservoir area, and the South-North Water Transfer Project [3]. Many factors affect rock softening, including the temperature, confining pressure, porosity, and water content [4]. Currently, with the prominent problem of rock engineering in high-temperature environments, the influence of temperature on the mechanical properties of rock has become an important research direction.…”

Section: Introductionmentioning

confidence: 99%

Effects of Different Temperatures on the Softening of Red-Bed Sandstone in Turbulent Flow

Liu

Cui

et al. 2019

JMSE

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The rates of chemical reactions are highly dependent on temperature, meaning that the actual geological rock mass is affected by different temperatures. Only when the temperature effect is considered can the mechanism of the influence of temperature on the interaction between water and rock be further understood. It was found that the condition of turbulent flow is more likely to promote the softening of red-bed sandstone than the conditions of laminar flow and static water in an experimental study on the softening effects of different flow patterns on red-bed sandstone. Therefore, based on a multi-functional self-circulating open channel hydraulic test system, this paper designs and completes equal volume saturated tests of red-bed sandstone at low temperature (1 °C), medium temperature (23 °C), and high temperature (45 °C) under the turbulent conditions of three equal temperature gradients. The chemical action of the circulating solution in water flow at different temperatures, the propagation of micro-cracks in rock and the changes in mechanical indexes are discussed. The influence laws and mechanisms of the different temperatures on the softening of red-bed sandstone in turbulent flow are revealed. The results show that low-temperature flow can inhibit the softening of red-bed sandstone in the range of 1–45 °C. With the increase in water flow temperature, the development degrees of micro-structures and the mechanical damage of the corresponding rock become more notable. That is, temperature affects the physical and chemical water–rock interactions and then changes the internal structure of rock, thus affecting the softening and failure processes of red-bed sandstone. The study provides a theoretical basis for the further investigation of the softening laws and mechanisms of other red layered soft rocks by temperature under turbulent conditions.

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“…Time-dependent failure is common in soft rock [1][2][3], and at times, 70% of the engineering deformation is caused by creep [4]. Recently, many geological disasters in Tibet and the Three Gorges of China are related to uncontrollable soft rock creep, so it is important to study the creep behavior of soft rock [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Burger’s Bonded Model for Distinct Element Simulation of the Multi-Factor Full Creep Process of Soft Rock

Xia

Liu

Zhou

2021

JMSE

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Pervasive, unavoidable and uncontrollable creep failure generated in soft-rock engineering occasionally happens and therefore attracts extensive attention recently. However, due to soft rock’s multi-factor creep mechanism, it is still difficult to simulate the full-stage creep with the Distinct Element Method (DEM). In this study, we proposed an improved simulation method based on the classical Burger’s model and the Parallel Bonded model in Particle Flow Code (PFC). We apply the abovementioned models together to simulate the full-stage creep process in soft rock. The proposed process has considered the mesoscopic mechanical characteristics of DEM carefully and finally resulted in a parallel physical model, which is called Burger’s Bonded model in this paper. The DEM simulation test using Burger’s Bonded model was designed to compare with experiments. The experiments include a normal creep test and a uniaxial loading test with prefabricated cracks. In contrast to experimental results, the numerical results show that the average error during the whole creep process is less than 3%; the stress–strain curves and crack development process show great agreement. It is also found that the wing crack coalescence in soft rock is independent of the prefabricated crack angle, propagating with a fixed dip angle. The results show that the numerical method proposed in this paper can simulate the multi-factor-caused full stage (attenuated, steady, accelerated) creep process of soft rock in DEM, which provides new insights for theoretical research and engineering design.

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Influence Mechanism of Different Flow Patterns on the Softening of Red-Bed Soft Rock

Cited by 17 publications

References 14 publications

Study on the Influence of Water–Rock Interaction on the Stability of Schist Slope

Study on the Influence of Water–Rock Interaction on the Stability of Schist Slope

Effects of Different Temperatures on the Softening of Red-Bed Sandstone in Turbulent Flow

Burger’s Bonded Model for Distinct Element Simulation of the Multi-Factor Full Creep Process of Soft Rock

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