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Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions

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A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Earth Sciences".

Deadline for manuscript submissions: closed (20 May 2023) | Viewed by 22353

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Prof. Dr. Zhengzhao Liang

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Guest Editor

Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian, China
Interests: rock mass; failure behavior; high stress; experimental method; numerical simulation

Prof. Dr. Nuwen Xu

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Guest Editor

State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610065, China
Interests: rock mechanics
Special Issues, Collections and Topics in MDPI journals

Dr. Bei Jiang

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Guest Editor

Stake Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
Interests: rock mechanics; underground engineering; numerical methods; numerical modeling in geotechnical engineering; tunneling; confined concrete support
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Recent years have witnessed a clear trend of developing deeper and longer tunnels to meet the growing needs of the mining, hydropower, and transportation industries. The demands for exploration of underground space, energy, and resources have necessitated the safe construction of underground tunnels. At the same time, underground transport becomes an appealing solution to address urbanization problems and facilitate connections between cities. The failure behavior of deep underground rocks under high stress becomes an important issue in rock mechanics and is of great significance to stability evaluation in rock engineering practices, such as underground excavation, shale gas production, and deep tunnel transportation. High stress applied on rocks makes their failure much different and more complex. Therefore, it is of great importance to assess the failure mechanism of brittle rock under high stress conditions.

Some new laboratory experimental techniques and numerical simulation methods for understanding rock mechanical behavior have appeared in recent years. This Research Topic aims to highlight the influence of high stress on the failure behaviors and mechanical properties of brittle rock under high stress. Submissions of original research articles, review articles, and case studies are all welcome.

Potential topics include, but are not limited to:

Failure mechanism of brittle rock under high stress
Mechanical properties of brittle rock under high stress
Damage constitutive model of brittle rock under high stress
Analysis and evaluation of deep rock engineering
New numerical simulation method for deep brittle rock
New technology of deep brittle rock test

Prof. Dr. Zhengzhao Liang
Prof. Dr. Nuwen Xu
Dr. Bei Jiang
Guest Editors

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Published Papers (14 papers)

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Editorial

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4 pages, 181 KiB

Open AccessEditorial

Special Issue on Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions

by Zhengzhao Liang, Na Wu, Nuwen Xu and Jiang Bei

Appl. Sci. 2023, 13(14), 8429; https://doi.org/10.3390/app13148429 - 21 Jul 2023

Viewed by 588

Abstract

To meet the demands of the mining, hydropower, and transportation industries, deep rock mass engineering in China has rapidly developed [...] Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

Research

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17 pages, 9731 KiB

Open AccessArticle

Numerical Study on the Dynamic Propagation Model of Cracks from Different Angles under the Effect of Circular Hole Explosion

by Junwei Zhang, Duanying Wan, Weiting Gao, Lei Zhou and Meng Wang

Appl. Sci. 2023, 13(13), 7955; https://doi.org/10.3390/app13137955 - 7 Jul 2023

Cited by 1 | Viewed by 856

Abstract

A dynamic disturbance will induce cracks around the tunnel in tunnel blasting or shield construction. To investigate the overall stability of cracks with various angles during a fixed borehole (round hole explosion) blasting, models containing an individual crack with different angles were introduced for simulation research. The research set up a thin sheet model with a length of 350 mm and a width of 150 mm, with a 7 mm diameter hole and a pre-existing crack of 75 mm and 5 mm in the middle. The evolution of the stress wave propagation model and the crack propagation model were simulated using the AUTODYN software. And in this study, the theory of stress wave is used to creatively explain the dynamic load under the action of formation and reasons for the danger zone. The results indicate that pre-existing cracks from different angles will have an impact on the blast hole and the new cracks generated around itself. At 45–90°, pre-existing cracks will direct reflected stress waves to promote some cracks around the hole to have faster growth rates than others, and these special cracks with faster growths and longer lengths will more easily connect with the free surface or other cracks, resulting in overall instability. And these conditions are consistent with the prediction made by the stress wave propagation simulation study. The research results have certain guiding significance for the stability analysis and hazardous area prediction of tunnel blasting with existing cracks. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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17 pages, 12488 KiB

Open AccessArticle

Experimental Study on the Mechanical Properties and Acoustic Emission Characteristics of Deep Soft Rocks under Low-Frequency Dynamic Disturbance

by Ling Dong, Dong Wang, Xiaoming Sun, Yujing Jiang, Hengjie Luan, Guangchao Zhang, Guanglei Zhou and Bin Liang

Appl. Sci. 2023, 13(11), 6399; https://doi.org/10.3390/app13116399 - 24 May 2023

Cited by 3 | Viewed by 1004

Abstract

The strong dynamic disturbance in deep mines seriously affects the safe and efficient mining of deep resources. In this study, we used the creep disturbance impact loading system and acoustic emission system to conduct experiments on soft siltstone specimens under a combination of dynamic and static loads. Based on the failure characteristics and waveform signals, the mechanical properties and acoustic emission characteristics of soft rocks under different dynamic disturbances were quantitatively revealed. The experimental results show that: (1) Under the dynamic disturbance, the deformation of the siltstone specimens increases as the initial average stress increases. When the axial stress exceeds the upper stress threshold, cracks continue to propagate, resulting in the destabilization of the specimen. (2) The magnitude of the initial average stress is closely related to the degree of damage and failure mode of the siltstone. With the increase in the initial average stress, the failure mode of the siltstone specimens gradually changes. As the initial average stress increases, the maximum load first decreases, then increases, and finally decreases, and the fitted curve is polynomial. We used the RFPA2D cyclic loading module to analyze the effect of the elastic modulus of each loading step on the damage evolution of the specimen under dynamic disturbance. The waveform characteristics during the evolution of the damage of the specimens were analyzed by extracting signals at the key points. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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16 pages, 7047 KiB

Open AccessArticle

Inversion Analysis of the In Situ Stress Field around Underground Caverns Based on Particle Swarm Optimization Optimized Back Propagation Neural Network

by Hong-Chuan Yan, Huai-Zhong Liu, Yao Li, Li Zhuo, Ming-Li Xiao, Ke-Pu Chen, Jia-Ming Wu and Jian-Liang Pei

Appl. Sci. 2023, 13(8), 4697; https://doi.org/10.3390/app13084697 - 7 Apr 2023

Cited by 4 | Viewed by 1295

Abstract

The in situ stress distribution is one of the driving factors for the design and construction of underground engineering. Numerical analysis methods based on artificial neural networks are the most common and effective methods for in situ stress inversion. However, conventional algorithms often have some drawbacks, such as slow convergence, overfitting, and the local minimum problem, which will directly affect the inversion results. An intelligent inverse method optimizing the back-propagation (BP) neural network with the particle swarm optimization algorithm (PSO) is applied to the back analysis of in situ stress. The PSO algorithm is used to optimize the initial parameters of the BP neural network, improving the stability and accuracy of the inversion results. The numerical simulation is utilized to calculate the stress field and generate training samples. In the application of the Shuangjiangkou Hydropower Station underground powerhouse, the average relative error decreases by about 3.45% by using the proposed method compared with the BP method. Subsequently, the in situ stress distribution shows the significant tectonic movement of the surrounding rock, with the first principal stress value of 20 to 26 MPa. The fault and the lamprophyre significantly influence the in situ stress, with 15–30% localized stress reduction in the rock mass within 10 m. The research results demonstrate the reliability and improvement of the proposed method and provide a reference for similar underground engineering. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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16 pages, 6483 KiB

Open AccessArticle

Formation Mechanism and Control Technology of an Excavation Damage Zone in Tunnel-Surrounding Rock

by Hongxian Fu, Xiaoming Guan, Chun Chen, Jianchun Wu, Qiqiang Nie, Ning Yang, Yanchun Liu and Junwei Liu

Appl. Sci. 2023, 13(2), 1006; https://doi.org/10.3390/app13021006 - 11 Jan 2023

Cited by 3 | Viewed by 1565

Abstract

Loosened rock circle is formed around the tunnel when the tunnel is constructed by the drilling and blasting method. The size of the loosened rock circle around the tunnel and the degree of internal rock fragmentation has an important influence on the support parameters, durability, and safety of the tunnel. Firstly, referencing an existing tunnel project, blasting tests using nonelectronic and electronic detonators were carried out to determine the influence of blasting construction on the scope of the rock loose circle and the degree of rock fragmentation. Then, a numerical simulation was used to study the contribution of the blasting impact and surrounding rock stress redistribution on the loosened rock circle around the tunnel. The results showed that the range of the loosened rock circle around the tunnel generated by the normal blasting of nonelectronic detonators was 1.5~2.3 m, and the wave velocity of the rock mass in the loosened rock circle around the tunnel decreased to 23~36%. The size of the loosened rock circle around the tunnel generated by the blasting impact was 0.66 m, accounting for 33% of the range of the loosened rock circle around the tunnel. The range of the loosened rock circle around the tunnel produced by electronic detonator blasting was 0~1.4 m. The wave velocity of the rock mass in the loosened rock circle around the tunnel decreased to 12~17%. The range of the loosened rock circle around the tunnel was approximately 60~76% of that of detonator blasting, and the broken degree of the surrounding rock in the loosened rock circle around the tunnel was small. The research results can provide a reference for the optimization design of preliminary support parameters of tunnels, such as anchors and steel arches in blasting construction. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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16 pages, 11682 KiB

Open AccessArticle

Tensile Characteristics and Fracture Mode of Frozen Fractured Rock Mass Based on Brazilian Splitting Test

by Tingting Wang, Pingfeng Li, Chun’an Tang, Bingbing Zhang, Jiang Yu and Tao Geng

Appl. Sci. 2022, 12(22), 11788; https://doi.org/10.3390/app122211788 - 20 Nov 2022

Cited by 6 | Viewed by 1508

Abstract

Frozen fractured rock mass is often encountered during the implementation of geotechnical engineering in cold regions. The tensile strength parameters of frozen rock play an important role in the construction of rock slopes involving tensile failure. In order to study the tensile characteristics of a frozen fractured rock mass in a cold region, original rock specimens were mined and processed in the Yulong Copper Mine, and artificial, frozen fractured marble specimens were made. The effects of different ice-filled crack angles, lengths, and widths on the force–displacement curve and the tensile strength of frozen rock were studied by laboratory Brazilian splitting experiments and RFPA^3D, and the evolution law of the tensile strength of frozen rock was revealed. At the same time, wing crack initiation and cracking mode after tensile failure were analyzed by high-speed camera; the whole process of the Brazilian splitting of frozen rock was reconstructed, and the development of microcrack initiation in frozen rock was analyzed. The following conclusions were drawn from the test results: the frozen rock specimens have typical brittle-failure characteristics. The tensile strength of frozen rock decreases gradually with the increase in the width and length of ice-filled cracks, and decreases first and then increases with the increase in the angle of the ice-filled crack. The ice-filled crack incurs damage first, and then the wing cracks start from the tip of the ice-filled crack and extend continuously. The tensile strength of frozen rock is significantly affected by the angle and length of ice-filled cracks. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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14 pages, 7626 KiB

Open AccessArticle

Stability Analysis of Surrounding Rock in the Diversion Tunnel at the Xulong Hydropower Station based on RFPA^3D and Microseismic Monitoring

by Hongjian Qian, Zhou Tan and Biao Li

Appl. Sci. 2022, 12(19), 9939; https://doi.org/10.3390/app12199939 - 2 Oct 2022

Cited by 2 | Viewed by 1431

Abstract

To study the surrounding rock stability of the excavated geologically weak section of the #2 diversion tunnel in the Xulong Hydropower Station, a quasi-3D numerical model was built using the Realistic Failure Process Analysis (RFPA^3D) system to simulate the damage and failure process consisting of crack initiation, growth, and penetration in the rock mass after tunnel excavation, and reveal the instability failure mechanism inside the rock mass. Moreover, the microseismic monitoring technology was employed to delineate potential danger areas in the surrounding rock of the tunnel and explore possible instability failure modes. Results indicate that the surrounding rock of the tunnel profile failed as different degrees during the excavation process, most obviously near the vault and corners of the side wall, where tensile failure predominated. As the excavation proceeded, microseismic events increased gradually at the vault and corners of the side wall, and the energy from acoustic emissions accumulated steadily, thus raising the possibility of collapse and rock bursts in this area. The research results can provide technical support for the construction of the diversion tunnel project in the Xulong Hydropower Station and serve as a guide for the construction of similar geologically weak underground projects. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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15 pages, 7309 KiB

Open AccessArticle

Sensitivity Analysis of Fracture Geometry Parameters on the Mechanical Behavior of Rock Mass with an Embedded Three-Dimensional Fracture Network

by Na Wu, Zhengzhao Liang, Yan Tao, Ting Ai and Guijie Li

Appl. Sci. 2022, 12(18), 9284; https://doi.org/10.3390/app12189284 - 16 Sep 2022

Cited by 3 | Viewed by 1215

Abstract

The existence of fractures has a significant influence on the mechanical properties of a rock mass. The sensitivity of the rock mass’s mechanical properties to the fracture’s geometric parameters is conducive to improving the measurement accuracy of fractured rock mass engineering. Firstly, the fracture geometric parameters in the dam site area of Lianghekou Hydropower Station were counted using the ShapeMetriX^3D system. Then, the effect of the fracture’s geometric parameters on the deformation characteristics, failure mode, and mechanical parameters of the rock mass were investigated based on the RFPA^3D under the uniaxial compression test. The results showed that the stress–strain curves of the fractured rock mass mainly exhibited elastic-brittle characteristics. The failure pattern of the fractured rock mass was mainly defined by a compressive-shear composite. Additionally, the influence of the fracture’s geometric parameters on the uniaxial compressive strength (UCS) was greater than that of elastic modulus. The sensitivity of the UCS to fracture trace length was more significant. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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16 pages, 7519 KiB

Open AccessArticle

Study on Failure Mechanism of Mudstone Based on Digital Core and Digital Volume Correlation Method

by Dong Duan, Xiaoyu Chen, Xiaojing Feng, Xin Wang and Jiang Sun

Appl. Sci. 2022, 12(15), 7933; https://doi.org/10.3390/app12157933 - 8 Aug 2022

Cited by 2 | Viewed by 1381

Abstract

In order to study the damage evolution law and failure mechanism of mudstone under different stress states, with the help of high-resolution CT scanning equipment, in situ CT scanning experiments of mudstone under uniaxial compression were carried out. Combined with digital core technology and the digital volume image correlation method, the 3D characterization of meso-structure and the evolution process of localized damage in mudstone were analyzed. The research shows that brittle minerals such as quartz in mudstone often exist in the form of agglomerated strips, resulting in the formation of weak structural planes at the contact surfaces of different minerals. There are a large number of primary intergranular pores near the mineral accumulation zone. With the increase in axial load, the connectivity of pores will gradually increase, cracks will gradually emerge, internal pores will develop abnormally, and rocks will reach the critical state of failure; at this time, the throat number and coordination number of pores increase obviously. There was no obvious difference found in the distribution of mineral particles of different sizes, and the slip between mineral zones was mainly dominated by small particles. The accumulated mineral zone was able to easily form a weak surface, and the aggregated mineral zone under loading was easily able to produce local deformation, which is related to the mechanical properties of the mineral zone and its surrounding rock matrix, with the rock failure easily occurring along the junction of the two minerals. The displacement in the polymeric mineral zone was small, the deformation displacement of the rock skeleton dominated by clay minerals near the quartz mineral zone was larger, and the stronger quartz minerals restrained the rock skeleton deformation in the region. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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20 pages, 23905 KiB

Open AccessArticle

Dynamic Mechanical Behavior of the Frozen Red Sandstone under Coupling of Saturation and Impact Loading

by Junce Xu, Hai Pu and Ziheng Sha

Appl. Sci. 2022, 12(15), 7767; https://doi.org/10.3390/app12157767 - 2 Aug 2022

Cited by 6 | Viewed by 2332

Abstract

Saturation is one of the critical factors causing frost damage to rock masses in alpine regions, and dynamic stress perturbations further complicate the damage process. Therefore, the effects of water content and loadings should be considered in the construction and maintenance of rock structures during winter in cold regions. In this study, the effects of saturation and impact loading on the dynamic mechanical behavior of frozen red sandstone were investigated using a low-temperature split Hopkinson pressure bar system (LT-SHPB). By combining low-field nuclear magnetic resonance (LF-NMR) and scanning electron microscopy (SEM), the dynamic evolution of the microstructure of the frozen sandstone due to changes in saturation was investigated. The results indicated that the increase of saturation reshapes the pore structure of the frozen sandstone and promotes the expansion of pores of different sizes during freezing, while at complete saturation the frozen samples are mainly developed with meso- and macropores. The dynamic strength, elastic modulus, and brittleness index of the frozen sandstone under impact loading, which are limited by the critical saturation Src, tend to increase and then decrease with saturation. For the four impact loads, the dynamic strength of the samples increased by 21.2%, 27.1%, 32.5%, and 34.3% when the saturation was increased from 0 to 50%, corresponding to 1.38, 1.43, 1.51, and 1.56 times the dynamic strength of the fully saturated samples, respectively. In contrast, the ultimate deformation capacity of the frozen sandstone showed an opposite trend with saturation. As the impact load increases, the dynamic strength, elastic modulus, and peak strain of the frozen sandstone show a significant strengthening effect due to the increase in strain rate, while its brittleness index gradually decreases, dropping by 11.2% at full saturation. In addition, the energy dissipation capacity of the frozen sample first increases and then decreases with increasing saturation, with the enhancement effect of saturation on energy dissipation smaller than the weakening effect. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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19 pages, 6512 KiB

Open AccessArticle

Tensile Properties and Tensile Failure Criteria of Layered Rocks

by Min Gao, Zhengzhao Liang, Shanpo Jia and Jiuqun Zou

Appl. Sci. 2022, 12(12), 6063; https://doi.org/10.3390/app12126063 - 15 Jun 2022

Cited by 4 | Viewed by 1575

Abstract

Rocks are less resistant to tension than to compression or shear. Tension cracks commonly initiate compression or shear failure. The mechanical behavior of layered rocks under compression has been studied extensively, whereas the tensile behavior still remains uncertain. In this paper, we study the effect of layer orientation on the strength and failure patterns of layered rocks under direct and indirect tension through experimental and numerical testing (RFPA^2D: numerical software of Rock Failure Process Analysis). The results suggest that the dip angle of the bedding planes significantly affects the tensile strength, failure patterns, and progressive deformation of layered rocks. The failure modes of the layered specimens indicate that the tensile strength obtained by the Brazilian disc test is not as accurate as that obtained by the direct tension test. Therefore, the modified Single Plane of Weakness (MSPW) failure criterion is proposed to predict the tensile strength of the layered rocks based on the failure modes of direct tension. The analytical predictions of the MSPW failure criterion agrees closely with the experimental and numerical results. In rock engineering, the MSPW failure criterion can conveniently predict the tensile strength and reflect the failure modes of layered rocks (such as shale, slate, and layered sandstone) with satisfactory accuracy. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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19 pages, 6196 KiB

Open AccessArticle

Seepage Characteristics and Failure Prediction during the Complete Stress–Strain Process of Limestone under High Water Pressure

by Chunyan Bao, Yong Yin, Shibin Tang, Annan Jiang and Hong Li

Appl. Sci. 2022, 12(12), 6041; https://doi.org/10.3390/app12126041 - 14 Jun 2022

Cited by 1 | Viewed by 1173

Abstract

The seepage characteristics during the complete stress–strain process of limestone under high water pressure were simulated via an experimental study of limestone post-peak penetrating behavior, and an approach to predict the formation of the seepage channel, namely, acoustic emission positioning technology, is proposed. The results showed that (1) whether in the experiment or in the numerical simulation, the sudden drop in the stress–strain curve after peaking indicated the full formation of shear fractures and seepage paths. (2) By using acoustic emission positioning technology in the simulation, the entire stress–strain process of limestone, from microfracture initiation and compaction to transfixion, could be monitored to observe the dynamic and real-time development of the microfractures. (3) The combination of acoustic emission technology with seepage monitoring revealed the real-time location and growth direction of micro ruptures and predicted the depth of penetration. The developed approach can improve forecast accuracy for landslides involving a low-permeability rock mass with cracks. In this study, limestone post-peak seepage characteristics were analyzed, and a method to forecast the formation of rock seepage paths before transfixion is provided. This work could provide a reference and guiding elements for ensuring the safety of slopes with high internal water pressure. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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15 pages, 48343 KiB

Open AccessArticle

Study on the Dynamic Splitting Mechanical Properties of Annular Sandstone Specimens with Temperature–Water Coupling in a Coal Mine

by Qi Ping, Qi Gao, Yulin Wu, Chen Wang, Kaifan Shen, Shuo Wang, Shiwei Wu and Yijie Xu

Appl. Sci. 2022, 12(9), 4608; https://doi.org/10.3390/app12094608 - 3 May 2022

Cited by 6 | Viewed by 1394

Abstract

With the gradual deepening of mine excavation depth, the strong disturbance of deep strata becomes more and more obvious. Rock’s failure under blasting mainly depends on its dynamic tensile strength. The changes in rock’s dynamic properties are obviously affected by temperature and water. In order to study the dynamic tensile properties of annular sandstone specimens under the influence of temperature and water, deep sandstone was drilled, followed by water bath tests at eight temperatures (25~95 °C). It can be seen from the analysis of test results that the mass and volume growth rates of the annular and the intact sandstone specimens first increased and then decreased, while the density growth rate first decreased and then increased. The mass and volume growth rates of the annular sandstone specimens were smaller, but the density growth rate was larger. Because of the increase in water temperature, the dynamic compressive strength first increased and then decreased. The dynamic tensile strength of the annular sandstone specimen was lower. The average strain rate and peak strain also showed a quadratic function relationship of first decreasing and then increasing with the increase in water temperature. The average strain rate of the annular sandstone specimen was smaller, but the peak value changed greatly. The Brazilian disc validity condition is applicable to two failure conditions of sandstone specimens. Through XRD and SEM analysis, we found that the changes in the dynamic properties of sandstone specimens were not due to their own material composition, but to the damage to their structure caused by the temperature–water coupling effect. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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28 pages, 15653 KiB

Open AccessArticle

Numerical Simulation Study of Brittle Rock Materials from Micro to Macro Scales Using Digital Image Processing and Parallel Computing

by Xin Liu, Zhengzhao Liang, Siwei Meng, Chunan Tang and Jiaping Tao

Appl. Sci. 2022, 12(8), 3864; https://doi.org/10.3390/app12083864 - 11 Apr 2022

Cited by 5 | Viewed by 1814

Abstract

The multi-scale, high-resolution and accurate structural modeling of rocks is a powerful means to reveal the complex failure mechanisms of rocks and evaluate rock engineering safety. Due to the non-uniformity and opacity of rocks, describing their internal microstructure, mesostructure and macro joints accurately, and how to model their progressive fracture process, is a significant challenge. This paper aims to build a numerical method that can take into account real spatial structures of rocks and be applied to the study of crack propagation and failure in different scales of rocks. By combining the failure process analysis (RFPA) simulator with digital image processing technology, large-scale finite element models of multi-scale rocks, considering microstructure, mesostructure, and macro joints, were created to study mechanical and fracture behaviors on a cloud computing platform. The Windows-Linux interactive method was used for digital image processing and parallel computing. The simulation results show that the combination of a parallel RFPA solver and digital image modeling technology can achieve high-resolution structural modeling and high-efficiency calculation. In microscopic simulations, the influence of shale fractures and mineral spatial distribution on the fracture formation process can be revealed. In the mesostructure simulation, it can be seen that the spatial distribution of minerals has an impact on the splitting mode of the Brazilian splitting model. In the simulation of a joined rock mass, the progressive failure process can be effectively simulated. According to the results, it seems that the finite element parallel computing simulation method based on digital images can simulate the multi-scale failure process of brittle materials from micro to macro scales. Primarily, efficient parallel computing based on a cloud platform allows for the multi-scale, high-resolution and realistic modeling and analysis of rock materials. Full article

(This article belongs to the Special Issue Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions)

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