A nonstationary parameter model for the sandstone creep tests

Wang, Xingang; Yin, Yueping; Wang, Jiading; Lian, Baoqin; Qiu, Haijun; Gu, Tianfeng

doi:10.1007/s10346-018-0961-9

Cited by 51 publications

(25 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Figure 1, the rock mass destruction is obvious in the zone, which means the hydrofluctuation belt is a sensitive zone to the water-rock interaction of the bank slope [15,16]. Based on the sandstone creep behaviors under the coupling effects of seepage pressure and stress, a nonlinear nonstationary plasticviscous creep model which can describe the curve of sandstone creep tests is proposed [17]. To quantify the rate of change of rock mechanical properties, a modified Hoek-Brown failure criterion was proposed, in which a new parameter was introduced to model the cumulative damage to rocks after water saturation-dehydration circulation [18].…”

Section: Introductionmentioning

confidence: 99%

Sandstone Dynamical Characteristics Influenced by Water‐Rock Interaction of Bank Slope

Deng

Zhang

Zhi

et al. 2019

Advances in Civil Engineering

View full text Add to dashboard Cite

During the long-term reservoir operation, the seismic capability and dynamic response characteristics of the bank slope are of great importance to its safety evaluation content. Aimed at typical bank slopes, considering reservoir water level fluctuation and soaking-air drying cyclic interaction, an experiment has been designed and conducted. In addition, the cyclic loading test with different stress amplitudes was carried out in different water-rock cycles. The laboratory results indicate that (1) during the immersion-air dry circulation process, the damping ratio and damping coefficient of sandstone gradually increased while the dynamic elastic modulus decreased. It is obvious that the dynamic elastic modulus of sandstone decreases dramatically during the immersion-air dry circulation process, especially in the first six periods. Also, its variation curve fits with the logarithmic curve. (2) When the cyclic load stress amplitude increases from 10 MPa to 35 MPa, the damping ratio and coefficient of the rock sample gradually decreased while dynamic elastic modulus increased. each dynamic parameter shows a more obvious variation trend when the stress amplitude is lower than 25 MPa. (3) During the water-rock interaction process, the closely knit microstructure of rock gradually becomes loose and porous, which resulted in the degradation of macroscopic physical and mechanical properties of sandstone. (4) In the analysis of the seismic response of the bank slope, the actual water-rock interaction process and the seismic level of the bank slope should be more considered. To find out further accurate reflection in the earthquake resistance and dynamic response of the bank slope, it is necessary to select the reasonable dynamic parameter to carry out seismic research.

show abstract

Section: Introductionmentioning

confidence: 99%

Sandstone Dynamical Characteristics Influenced by Water‐Rock Interaction of Bank Slope

Deng

Zhang

Zhi

et al. 2019

Advances in Civil Engineering

View full text Add to dashboard Cite

show abstract

“…where K is the bulk modulus and G 1 , G 2 , and G 3 are the shear modulus, respectively, corresponding to E 1 , E 2 , and E 3 in the three-dimensional stress state. e four parameters K, G 1 , G 2 , and G 3 can be determined as follows [22]:…”

Section: Consideration Of Instantaneous Elastic Response To Ermal Trementioning

confidence: 99%

A Rheological Model of Sandstones considering Response to Thermal Treatment

Wang

Huang

Zhang

2019

Advances in Civil Engineering

Self Cite

View full text Add to dashboard Cite

Time-dependent rheological response of geomaterials to thermal treatment is a crucial issue in geothermal energy utilization and deep mineral mining. This response, however, has not yet been fully considered in the existing rheological constitutive models for sandstones. In order to experimentally investigate such responses and establish the associated rheological constitutive model, this study considers the sandstone specimens which have been thermally treated under different temperatures. The triaxial rheological test in conjunction with the scanning electron microscope is employed in the investigation to observe the mechanically and macro-/micromorphologically rheological response. Investigation results show that the thermal treatment induces microcracks and microdefects, and subsequently, they propagate during the creep. As a consequence, the heterogeneous deformation occurs, and macrocracks are present, leading to the irregular fluctuation and mutation in strain over time. A higher temperature contributes to a more severe structure damage and in turn reduces the intactness of sandstones and elevates the rheological response. The investigation allows successful establishment of a three-dimensional constitutive equation considering the instantaneous elastic response to thermal treatment. Based on the equation, a nonlinear visco-elastoplastic rheological constitutive model is developed for sandstones. Comparison with three existing rheological models shows that the model developed in this study could well represent the rheological process of the thermally treated sandstones.

show abstract

“…e Nishihara model which is widely used in the research on mechanical rheological properties of rocks, consisting of a Bingham body and a Kelvin (Voigt) body connected in series [25], is shown in Figure 1.…”

Section: Modified Nishihara Model and Its Constitutive Equationmentioning

confidence: 99%

“…where K is the bulk modulus of the specimen; G 1 and G 2 are the shear moduli corresponding to E 1 and E 2 in the threedimensional stress state [25].…”

Section: Rheological Equation Of the Modified Nishiharamentioning

confidence: 99%

Modified Nishihara Rheological Model considering the Effect of Thermal‐Mechanical Coupling and Its Experimental Verification

Wang

Huang

Lian

et al. 2018

Advances in Materials Science and Engineering

Self Cite

View full text Add to dashboard Cite

The effect of temperature and pressure, which play important roles in the mechanical properties of rocks during deep energy exploitation, has not been sufficiently studied in the previous rock creep models. In order to investigate thermal effect in creep models, a modified Nishihara rheological model, taking into account the coupled effect of thermal damage and stress, was proposed by combining the theoretical formula for thermal damage of rocks with the modified Nishihara model. The improved model introduces a nonlinear viscous dashpot, which can accurately describe the accelerated rheological phase of rocks. To verify the proposed model, a triaxial rheological experiment was conducted on sandstone subjected to thermal damage (600°C). In addition, the stress-strain curves within whole creep process of the rheological experiment were analyzed. Furthermore, the theoretical curves of the modified Nishihara rheological model were compared with the experimental results. Results showed that the theoretical curves relatively agree well with the experimental data, suggesting that the proposed new model is more preferred to describing the rheological curve of sandstone subjected to thermal damage at different rheological stages, in particular, it is capable of depicting the accelerated rheological stage of the sandstone, providing a good ability to describe the creep behavior of rocks under thermal-mechanical coupling.

show abstract

A nonstationary parameter model for the sandstone creep tests

Cited by 51 publications

References 46 publications

Sandstone Dynamical Characteristics Influenced by Water‐Rock Interaction of Bank Slope

Sandstone Dynamical Characteristics Influenced by Water‐Rock Interaction of Bank Slope

A Rheological Model of Sandstones considering Response to Thermal Treatment

Modified Nishihara Rheological Model considering the Effect of Thermal‐Mechanical Coupling and Its Experimental Verification

Contact Info

Product

Resources

About