A creep model for frozen sand of Qinghai-Tibet based on Nishihara model

Zhu, Zhanyuan; Luo, Fengming; Zhang, Yuanze; Zhang, Dongjie; He, Junlin

doi:10.1016/j.coldregions.2019.102843

Cited by 31 publications

(10 citation statements)

References 15 publications

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“…In [15], a new model of nonlinear creep is proposed, which makes it possible to describe the creep of frozen sand under various conditions, which was confirmed by experimental studies.…”

Section: Introductionmentioning

confidence: 75%

Experience of determining the parameters of the elastoviscoplastic soil model

2021

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Rheological studies of soils were carried out by S.S. Vyalov, M.N. Gol’dshtejn, N.N. Maslov, G.I. Ter-Stepanyan, S.R. Meschyan, A.L. Gol’din, Z.G. Ter-Martirosyan and many others. On the basis of existing rheological soil models, a new universal rheological equation was proposed in Ter-Martirosyan’s dissertation, which allows describing kinematic shear, creep and stress relaxation at the same parameters. Experimental studies of the soil were carried out in a simple shear device in a kinematic loading mode at a shear displacement rate u̇= 0.05 mm/min and at two values of compaction loads (σ1 < σ2). Based on the results of the experimental studies, the parameters of the elastoviscoplastic model were determined and graphs of the dependence of shear stresses on time were plotted, which clearly show the high convergence of the experimental and theoretical curves.

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“…In [15], a new model of nonlinear creep is proposed, which makes it possible to describe the creep of frozen sand under various conditions, which was confirmed by experimental studies.…”

Section: Introductionmentioning

confidence: 75%

Experience of determining the parameters of the elastoviscoplastic soil model

2021

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“…At the same time, an improved Nishihara model was established based on the Nishihara model by considering different influencing factors, and it was also verified through the application. In the above aspects, a lot of important research work has been done to put forward many modified models for specific rock strata (Liu et al, 2017;Cao et al, 2017;Wang et al, 2018;Zhu et al, 2019;Jin et al, 2019;Wang et al, 2019;Li et al, 2020;. However, their general applicability is limited to a certain extent.…”

Section: Introductionmentioning

confidence: 99%

Deformation Prediction of Tunnel-Surrounding Rock Considering the Time Effect of the Viscosity Coefficient: A Case of an NATM-Excavated Tunnel

Liang

et al. 2022

Front. Earth Sci.

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Considering engineering problems such as complicated stress and the difficulty in controlling large deformation while a tunnel passes through a soft rock stratum, a theoretical prediction model of convergence deformation of tunnel-surrounding rock is proposed. Based on the longitudinal displacement profile curve reflecting the “space effect” of the excavation surface, the Hoek formula with better applicability was introduced to analyze and theoretically deduct the “time–space effect comprehensively.” By taking the influence of the “time effect” coefficient into account, an improved Nishihara model was established to derive the analytical equation of the viscoelastic–viscoplastic convergence of surrounding rock. Taking the Dingxi Tunnel of Wujing Expressway in Hunan Province, the physical and mechanical parameters of surrounding rock in the tunnel were firstly determined then they were used to calculate and predict the vault down of three typical sections with the scoping equation of surrounding rock deformation. Based on the calculation results, the causes of the differences between the measured and theoretical values were analyzed; moreover, it is indicated that the minimum root-mean-square error is 1.68, the minimum average error is 1.3%, and the correlation coefficient is 0.99. The comparison shows that the theoretical prediction results agree well with the corresponding field test results. The improved Nishihara model can accurately predict the final deformation of the surrounding rock. Simultaneously, it is also proved that the relevant parameters and the hypothesis and correlation of the nonlinear viscosity coefficient equation are reasonable, with particular effectiveness and applicability in practical engineering. This study is significant for further studying the tunnel-surrounding rock’s stability and accumulating theoretical and practical experience to develop rheological theory.

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“…Furthermore, researchers are also committed to studying the creep characteristics and theoretical model of frozen rock and soil. Zhu et al. (2019) found that temperature has a significant effect on the rheological properties of frozen sand; considering the influence of time and stress, and introducing a damage variable to improve the viscoplastic element, a new nonlinear creep constitutive model of frozen sand was proposed.…”

Section: Introductionmentioning

confidence: 99%

“…Thus, numerous scientific efforts have been devoted to studying the creep strength, time-dependent deformation, damage propagation, failure characteristics and theoretical model in uniaxial/triaxial, bending, and shear rheological tests (Challamel et al, 2005;Cruden, 1971;Itoˆand Sasajima, 1987;Mishra and Verma, 2015;Nadimi and Shahriar, 2014;Rassouli and Zoback, 2015;Tomanovic, 2006;Tsai et al, 2008). In recent years, for special engineering problems, many researchers began to study the rheological properties of soft rock (Cao et al, 2016;Mansouri and Ajalloeian, 2018), rock containing pre-existing flaws (Shi et al, 2019;Wu et al, 2018), frozen soil (Cao et al, 2018;Hou et al, 2018;Kostina et al, 2018;Zhou et al, 2018;Zhu et al, 2019) and frozen rock (Ladanyi, 2006;Song et al, 2019) due to the complex and variable occurrence, environment, lithology and structure of rock. Wang et al (2014) investigated the creep damage behavior of rock salt, gave the evolution rule of deformation and failure in three stages, and evaluated the long-term strength of rock salt.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, researchers are also committed to studying the creep characteristics and theoretical model of frozen rock and soil. Zhu et al (2019) found that temperature has a significant effect on the rheological properties of frozen sand; considering the influence of time and stress, and introducing a damage variable to improve the viscoplastic element, a new nonlinear creep constitutive model of frozen sand was proposed. Kodama et al (2019) investigated the impact of the water content of specimens on the time-dependence of mechanical behavior and found that pore ice had a great influence on the deformation and failure of frozen wet rock specimens.…”

Section: Introductionmentioning

confidence: 99%

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Study on triaxial creep behavior and the damage constitutive model of red sandstone containing a single ice-filled flaw

Bai

Shan

Han

et al. 2020

International Journal of Damage Mechanics

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The freezing method is widely used in the construction of vertical shafts in water-rich strata. The formed frozen rock wall is often involved in the creep process, and in particular, the creep behavior of frozen fissured rock mass poses a great threat to construction safety. To better understand the creep instability law of ice-filled, fractured red sandstone under freezing and triaxial stress conditions, a series of triaxial creep tests on frozen red sandstone specimens containing a single, pre-existing flaw at −10°C and under a confining pressure of 4 MPa were carried out with a self-developed DRTS-500 subzero rock triaxial testing system. The multistage loading creep curves were obtained, and the evolution laws of deformation and damage for the frozen specimens in the primary (instantaneous), secondary (steady-state) and tertiary (accelerating) phases were analyzed. The nonlinear visco-elastoplastic constitutive model of red sandstone with a single ice-filled flaw was established according to the fractional calculus theory and the Kachanov damage theory. The results show that the initial creep property, unstable creep property and creep failure mode of frozen single-flaw red sandstone are significantly affected by the flaw dip angle. The proposed creep damage model can accurately describe the complete creep curves of frozen red sandstone with a single ice-filled flaw, especially in the unstable creep stage. The influences of the stress level and flaw dip angle on the creep parameters were analyzed, and sensitivity analyses of the characteristic creep parameters were carried out to verify the reliability and rationality of our creep model. This research can be applied to the assessment of collapse, cracking and other long-term failures and hence can be used as a theoretical basis of design in the freezing engineering of coal mine shafts.

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A creep model for frozen sand of Qinghai-Tibet based on Nishihara model

Cited by 31 publications

References 15 publications

Experience of determining the parameters of the elastoviscoplastic soil model

Experience of determining the parameters of the elastoviscoplastic soil model

Deformation Prediction of Tunnel-Surrounding Rock Considering the Time Effect of the Viscosity Coefficient: A Case of an NATM-Excavated Tunnel

Study on triaxial creep behavior and the damage constitutive model of red sandstone containing a single ice-filled flaw

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