Lei Xue

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Verified

Lei verified their affiliation via an institutional email.

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• PhD
• Professor (Associate) at Institute of Geology and Geophysics, Chinese Academy of Sciences

To reveal the influence of dynamic load on the dynamic damage behavior of jointed rock masses, split Hopkinson pressure bar (SHPB) system was employed to test platy gabbro samples with joint angles of 15°, 30°, 45°, 65°, and 75° at an impact pressure of 0.1 MPa. It was found that the joint angle has a significant effect on the dynamic characteristi...

Rock bridges have long been recognised to provide crucial resistance against rock mass failure. Multiple rock bridges with diverse scales are widespread in natural rock masses. Despite prior positive contributions to a single rock bridge, mechanical behaviours of diverse-scale rock bridges remain elusive. In particular, whether rock bridges interac...

The steep bedding rock slope (SBRS) is easily destabilized under earthquake action, so it is crucial to research the features of this kind of slope’s seismic dynamic reactions in order to prevent and mitigate disasters. Few researchers have examined these slopes from an energy perspective, and the majority of recent research focuses on the displace...

Despite the prevalence and validity of the universal distinct element code (UDEC) in simulations in geotechnics domain, water-weakening process of rock models remains elusive. Prior research has made positive contributions to a presupposed link between modelling parameters and saturation degree, Sr. Nevertheless, this effort presents inaccurate res...

Using residual soil from the Shanghecun landslide in the western Henan Province, shear creep tests of residual soil samples with different rock contents (RCs) were performed to explore the creep characteristics, creep rate, and long-term strength of the residual soil. The test results indicate that the residual soil samples with different RCs displ...

The long-term stability of slopes in areas with strong earthquakes not only is very important for people’s lives and the safety of property, but also it enables restoration of the ecological environment in the landslide areas, which is very important for sustainable development. The most commonly used seismic-support method, anti-slide piles, provi...

To investigate the stability and interaction mechanism of the slope-pile-footing system under surcharge effects, the finite difference method (FDM) was adopted to analyze the response laws of the stability of the reinforced slope, evolution of the critical slip surface, stress characteristic of retaining structures, deformation and failure modes of...

En-echelon joints are common in rocky slopes and faults, and their instability seriously threatens the safety of geotechnical engineering. Filling and reinforcing en-echelon joints in slopes is highly important for maintaining the safety of engineering and human beings. In view of this, this study aims to investigate the fracture behavior of en-ech...

A rock can undergo hardening deformation during compression and have a memory of the hardening action, which can be displayed when unloaded. This compression-hardening memory effect (CHME) is related to the micromechanical response of the heterogeneous rock microstructure. However, to date, the related mechanism has not been fully characterized. He...

Currently, most designs for landslide hazard control employ geotechnical measures as the primary strategy and vegetation measures as the supplemental strategy. However, few studies have investigated the synergistic protection effectiveness of combining geotechnical and vegetation measures. To evaluate the synergistic mechanism between roots and pil...

Repeated rainfall usually results in the weakening of the strength characteristics of the engineered rock masses, which can induce engineering accidents. To explore the effect of water-induced rock strength damage under the repeated action of saturation and drying, this study conducted compression experiments on red sandstone. Laboratory experiment...

The differences in geomechanical properties and the uncertainty in the spatial distribution of Bimrock pose significant challenges to the construction and disaster prediction of geotechnical engineering. To clarify the geomechanical characteristics of Bimrock, this paper summarizes the basic concepts and classification methods of Bimrock at home an...

The significance means of the seismic reinforcement effect of a pile-anchor system for slope reinforcement has been widely recognized. However, cases of deformation failure and instability sliding of the pile-anchor system itself and the reinforced slope under seismic action continue to be recorded. Therefore, it is crucial to evaluate the seismic...

Failure precursors with clear physicomechanical connotations are of great significance in predicting catastrophic instability in major constructions and rock engineering. Here, we conducted uniaxial compression tests on natural solid rocks and cement mortar materials and obtained their acoustic emission (AE) activity characteristics during the dama...

This study explores explore the failure characteristics of high temperature granite under different numbers of heating–cooling cycles. Combining a series of laboratory uniaxial compression tests with acoustic emission (AE) monitoring, it reveals the AE characteristics and damage behavior of high temperature granite in different damage stages. Incre...

Water-induced strength deterioration of rock mass is a crucial factor for rock slope instability. To better show the degradation process of rock slope water–rock interaction, we used bentonite as a water-sensitive regulator to build a new rock-like material that matches the features of water-induced strength degradation based on the cement-gypsum b...

The Universal Distinct Element Code (UDEC) has been rising much prevalence and is a validated technique applied to simulations in varied branches of geotechnics. Nevertheless, the characterization of water-weakening effects on a rock model remains elusive, resulting in a poor constraint referring to water-induced simulations by UDEC. In this contex...

Rock bridges control the stability of rock slopes with intermittent joints. To better understand the evolution of water-induced damage in rock bridges, we developed new, water-sensitive similar materials and investigated their physical, mechanical, and hydraulic properties. The reasonable proportions of the material components required to simulate...

Characterization on the response of the jointed rock mass to the stress wave is of great significance for rock engineering and the prevention of dynamic geological disasters. A joint in the rock mass produces discontinuous deformation under dynamic loads and can be weakened on both stiffness and strength, which further affect stress wave propagatio...

A series of laboratory-based uniaxial compression tests combined with acoustic emission (AE) monitoring was conducted to investigate the loading rate dependence of AE characteristics and the damage process of granite. Experimental results showed that the mechanisms of formation and evolution of cracks within the rock during loading can be character...

It has been recognized that the anisotropic structures dominate the deformation and strength properties of laminated rock masses. The resultant strength anisotropy is strongly affected by confining pressures beyond anisotropic structures. Nevertheless, the effects of confinement are inconsistent among existing experiments and not fully understood....

Vegetation slope protection has been widely utilized as an eco-friendly approach for slope stability. Up to now, research on the slope protection effect of shrubs and herbaceous vegetation is more than those of trees, which can be attributed to the challenge of evaluating the slope protection effect of tree root systems that can be influenced by ma...

In this study, we numerically examine the microcracking behaviors of Alxa porphyritic granite under direct shear using a novel grain-based model considering particle-scale softening mechanism. Associated acoustic emission (AE) activities were monitored using a moment tensor algorithm, and then the effects of normal stress on the microcracking behav...

Vegetation slope protection is widely used in slope support engineering as an ecologically friendly support method. There has been a lot of research on herbs and shrubs slope protection, but less on arbor slope protection. Using accumulation landslides as a research subject, a series of physical model tests of arbor slope protection were conducted,...

Landslides have posed a huge threat to the ecological environment and human society all over the world. As the most conventional reinforcement method, anti-slide piles are widely used in the reinforcement of slopes. Currently, more and more attention has been paid to the low-cost and high-efficiency optimal design of anti-slide piles. However, limi...

Due to the challenge of measuring rock bridges in the field and the negligence of progressive damage and changes in stresses within a rock mass when defining rock bridges, it is questionable to evaluate mechanical properties of rock bridges using only geometric parameters. A demonstration is the scale effects of rock bridges, because the same geome...

Stress thresholds are commonly used to quantify rock damage in many engineering constructions. In this study, we investigated the relationship between the crack damage stress threshold (σcd), peak strength (σucs) and shape parameter m. The effects of temperature, confining pressure and strain rate on m were also determined. The variation in the nor...

The Bailong River Diversion Project is a proposed major strategic project in China,and the Daigusi Reservoir is the water source hub of this project. The Daigusi Reservoir and its surrounding areas(the study area of this paper) are surrounded by many active faults and frequent major earthquakes. Therefore,a reliable seismic hazard assessment for th...

A model of a steep bedding rock slope with a slope angle of 50° and rock dip angle of 55° was designed and fabricated, and a large-scale shaking table test was carried out to investigate the acceleration, displacement, acoustic emission, and failure mode under earthquake action. In the vertical direction of the slope, the acceleration amplification...

The pore structure of rock changes significantly during the heat treatment process, which affects the internal emission rate of radon. This study introduces the results of radon emission rate of rock after high temperature and analyzes the effect of the pore structure in rock mass on radon emission. The results show that there is a good positive co...

It is believed that the bedding plane is one of controlling factors in progressive failure of shales and its characterization is of great significance in the gas shale engineering. However, it is often difficult to directly capture and visualize the progressive failure process of shales in practice. Although the microseismic method is feasible and...

A better understanding of energy evolution during brittle failure of hard rock is critical for safe excavation of underground openings, insight into rockburst phenomena, and earthquake mechanisms. According to Griffith’s theory of crack propagation, the mechanical behavior of rock during crack propagation is analyzed from a theoretical perspective,...

Acoustic emission (AE) characterization is an effective technique to indirectly capture the failure process of quasi brittle rock. In previous studies, both experiments and numerical simulations were adopted to investigate the AE characteristics of rocks. However, as the most popular numerical model, the moment tensor model (MTM) cannot be constrai...

The concept of joint persistence has been widely used to study the mechanics and failure processes of rock masses benefitting from the simplicity of statistical linear weighing of the discontinuity. Nevertheless, this term neglects the scale effects of rock bridges, meaning that the same joint persistence may refer to different numbers and spacings...

The recession of a coast can destabilize coastal cliffs. The stability of a cliff is controlled by a rock bridge. Identifying the volume-expansion point of rock bridges is crucial to assess cliff stability, but currently there are few identifying methods. Using a numerical analytical tool, we investigate the acoustic emission characteristics during...

Stability prediction of rock slopes under seismic loads is important for landslide hazard assessment. For this work we designed and built a model of a slope with a middle locked segment. To investigate its dynamic response characteristics and instability criteria under the influence of an earthquake, comparative experiments on a large-scale shaking...

It is believed that the loading rate significantly affects the damaging behaviors of layered rocks. However, previous studies have mainly focused on the inherent bedding structure rather than the loading rate, particularly in the case of shearing. In this paper, the discrete element method (DEM) was used to simulate the rate-dependent shear behavio...

Despite extensive investigations, no precursor patterns for reliably predicting major earthquakes have been identified as yet. Seismogenic locked segments that can accumulate adequate strain energy to cause major earthquakes are highly heterogeneous and low brittle. The progressive cracking of the locked segments with these properties can produce a...

Heavy rainfall has long been recognized as a key factor in the triggering of landslides, as large amounts of precipitation generally have strong weakening effects on anti-sliding forces along slip surfaces. However, it remains to be understood why the catastrophic Xintan landslide in China was triggered by only moderate rainfall rather than the are...

Acoustic emission (AE) characterization is an effective technique to indirectly capture the progressive failure process of the brittle rock. In previous studies, both the experiment and numerical simulation were adopted to investigate AE characteristics of the brittle rock. However, as the most popular numerical model, the moment tensor model (MTM)...

Determining rock damage thresholds is of great significance in predicting rock fracture. In this study, the relation among crack damage stress threshold (σcd), peak strength (σucs) and shape parameter m was observed. The impact imposed by temperature and confining pressure on m was then examined. The results show that there is an approximate linear...

Microwave assisted mechanical rock breaking is a hybrid rock breaking method that combines microwave heating and mechanical rock breaking technologies and is proven to have potential applications in mineral processing, mining, and geotechnical engineering. It is, thus, important to understand the effect of microwave-induced damage on rock fracture...

The reliable partition of seismic zones is very important for earthquake prediction and seismic hazard evaluation. We have recognized that an intraplate seismogenic tectonic block is laterally bounded by major faults, or by major faults and plate boundaries, and its bottom boundary is the Conrad discontinuity or the low-velocity and high-conductivi...

A correlation study between the fracability and brittleness of shale gas reservoir is crucial for optimize reservoir reconstruction and enhance shale gas recovery. To investigate the relationship between fracability and brittleness of shale, a series of uniaxial compression tests of Silurian Longmaxi shale samples were carried out using a novel set...

Landslides have posed a huge threat to the ecological environment and human society all over the world. As the most conventional reinforcement method, anti-slide piles are widely used in the reinforcement of slopes. Currently, more and more attentions have been paid to the low-cost and high-efficiency optimal design of anti-slide piles. However, li...

Laboratory tests revealed that by enhancing the weathering degree, a transition of pre-peak stress-strain mechanical responses of crystalline rocks under unconfined compression from approximate linearity to nonlinearity was evident, as was the weakening of macro-mechanical properties. However, thus far, very few numerical studies have been conducte...

Locked segment is the geological structure that governs the generation of tectonic earthquakes. As such, studying the energy conversion and allocation principle during the damage process of locked segment can make enhanced insights into its damage behavior and energy evolution mechanism. Based on the energy conservation principle, the relationship...

A rock mass often contains joints filled with a viscoelastic medium of which seismic response is significant to geophysical exploration and seismic engineering design. Using the propagator matrix method, an analytical model was established to characterize the seismic response of viscoelastic filled joints. Stress wave propagation through a single j...

Despite the enormous efforts towards searching for precursors, no precursors have exhibited real predictive power with respect to an earthquake thus far. Seismogenic locked segments that can accumulate adequate strain energy to cause major earthquakes are very heterogeneous and less brittle; progressive failures of the locked segments with these pr...

Despite the enormous efforts towards searching for precursors, no precursors have exhibited real predictive power with respect to an earthquake thus far. Seismogenic locked segments in a well-defined seismic zone that can accumulate adequate strain energy to cause major earthquakes are very heterogeneous and less brittle. Progressive failures of th...

The acoustic-emission (AE) nondestructive monitoring method was used to investigate the deformation–failure of Longmaxi marine shale samples from the Sichuan Basin in uniaxial compression tests. Millions of AE ring counts were recorded by six sensors that were mounted on the surface of cylindrical specimens. The AE ring counts rate and energy rate...

Natural locked segments dominate the stability of locked-segment-type slopes and the evolutionary process of tectonic earthquakes. They fail in order of bearing capacity from low to high. Therefore, it is very important to study the mechanical response mechanism of the next locked segment while the current locked segment is broken, and predict the...

Each of the seismogenic locked segments in a well-defined seismic zone can accumulate high strain energy to bring about major earthquakes. Hence, better understanding the physical implication of self-organized criticality in the locked segment (rock) failure process is crucial to achieving insights into such issues as earthquake predictability and...

An understanding of crack propagation is critical for the development of rock mechanic models. To study the propagation of internal cracks in situ and determine their formation mechanism, a series of uniaxial compression tests on shale specimens were conducted using a novel setup that combines X-ray micro-computed tomography (X-ray micro-CT) with a...

Applying the statistical damage theory based on the Weibull distribution to describe rock deformation and failure processes is an important development in rock mechanics. The shape parameter of the Weibull distribution, m, determines the basic shape of the distribution curve; additionally, it also represents a physical characteristic which can be a...

The evolution of porosity and changes in wave velocity in granite after high-temperature treatment has been experimentally investigated in different studies. Statistical analysis of the test results shows that there is a temperature threshold value that leads to variations in porosity and wave velocity. At a temperature that is less than 200 °C, th...

Based on both the lately-defined Wenchuan seismic zone (version 3.6) and the theory about the brittle failures of multiple locked patches in a seismogenic fault system, we reanalyzed several scientific issues related to the 2008 Wenchuan earthquake, e.g., “Is the Wenchuan earthquake a mainshock?”, “What's the relationship among the 2013 MS7.0 Lusha...

The slope, whose stability is controlled by the locked segments within a potential slip surface, is referred to as the locked-segment type slope. It is well known that the instability prediction of slopes is a worldwide scientific problem. We suggest here that solving the instability prediction of the locked-segment type slope could be taken as a b...

It is clear that evaluating the fracturing effect with laboratory tests can shed some light on designing fracturing programs for shale gas exploitation. To evaluate the fracturing effect quantitatively, a series of uniaxial cyclic loading tests on shale were conducted. Based on the experimental results, a damage variable derived from the total axia...

Predicting occurrence of landslides is very significant to avoid or reduce losses in lives and properties. Stability of rock slopes is often dominated by one or more locked patches. The locked patches along a potential slip surface resist failure and accumulate strain energy. Coupling one dimensional renormalization group model with the strain-soft...

Failure of jointed rocks is highly dependent on the presence of rock bridges that exist across joint surfaces. It has long been assumed that such bridges are homogeneous orders, but continued investigation has found that, more often than not, they are a heterogeneous order. In this paper, the failure processes of generalised rock bridges (including...

Seismic hazard assessment is very important for determining seismic fortification grade of engineering projects, making urban planning and reducing earthquake disasters. Due to some drawbacks of traditional evaluation methods, it is generally unreliable to assess seismic risk in a certain area by applying these methods. Based on the theory about th...

The theory about the brittle failures of multiple locked patches in a seismogenic fault system developed by us since 2010 is introduced in the present study. It is stated by the theory that the progressive failures of locked patch result in the occurrence of earthquakes due to fault movement, where the major earthquakes occurred at its volume expan...

The focus of the present study is to explain the stair-step brittle deformation evolutionary pattern of the landslide and reveal the corresponding internal physical mechanism. Based on the concept of high strength geological body (HSGB), similar to rock bridges in the intermittence jointed rock masses, a conceptual geological model and the correspo...

Understanding the physical mechanism of major earthquakes is very important for earthquake prediction and its disaster reduction. The mainstream hypotheses on earthquake mechanism are reviewed in this paper. It is pointed out that the elastic rebound and stick-slip hypotheses, both of which are usually used to explain the mechanism of shallow earth...

Understanding the physical mechanism of major earthquakes is very important for earthquake prediction and its disaster reduction. The mainstream hypotheses on earthquake mechanism are reviewed in this paper. It is pointed out that the elastic rebound and stick-slip hypotheses, both of which are usually used to explain the mechanism of shallow-focus...

High temperature may lead to the development of new microcracks or growth of pre-existing microcracks within granite, varying its physical and mechanical properties. Experiments were conducted to study the evolution of the physical and mechanical properties of granite specimens from room temperature to 800 °C. The specimens were heated in heating f...

In this study, we divided the Islamabad-Kathmandu seismic zone based on the brittle failure theory of multiple locked patches in a seismogenic fault system and principles for dividing interplate seismogenic zones. Furthermore, we analyzed the seismogenic process of the large or great earthquake events in the zone from the angles of the definition o...

Based on the brittle failure theory of multiple locked patches in a seismogenic fault system and interplate seismic zoning principle proposed by the authors of this paper, the Islamabad–Kathmandu seismic zone is defined. Through seismogenic period definition and main shock event recognition, the seismogenic process of major/great earthquakes in thi...

This paper reports an experimental study of the evolution of permeability during rock brittle failure and a theoretical analysis of rock critical stress level. It is assumed that the rock is a strain-softening medium whose strength can be described by Weibull's distribution. Based on the two-dimensional renormalization group theory, it is found tha...

Investigations of rocks with different moisture contents demonstrate that during the process of failure, the number of acoustic emissions (AE) increases in the vicinity of the yield point with the rapid generation and growth of micro cracks. The increase of moisture content leads to decreased rock strength and fewer events of AE, which suggests tha...

This paper investigated the theoretical relationship between the axial strain thresholds at the volumetric strain reversal point (ε 1cd) and the strain threshold at the peak stress (ε 1ucs) during a uniaxial compression test. Firstly, we used renormalization group theory with the stress transfer mechanism to reveal the essence of the phase transiti...

In this paper, we have investigated the quantitative relationship between the axial strain threshold at the volumetric strain reversal point (ε 1cd) and the strain threshold at the peak stress (ε 1ucs) during the uniaxial compression tests. We found that normalized values of ε 1ucs/ε 1cd for different rock types are typically ~1.34(±0.24). This is...

Two quantitative displacement criteria for slope deformation were deduced through the combination of a one-dimensional renormalization group model and the strain-softening constitutive model of geological materials. The criteria can be used to understand the mechanical process from the onset of the accelerating creep on a slope, through brittle rup...

When rock samples are loaded until macroscopic fractures develop, the failure process can be divided into several stages based on axial and lateral strain responses or the acoustic emission sequence during uniaxial compression tests. Several stress thresholds may be identified: the crack closure stress sigma (cc), crack initiation stress sigma (ci)...

Based on the two-dimensional renormalization group model, which can consider the stress transfer mechanism, in the present paper, the theoretical quantitative correlation between the threshold of the crack damage stress (σ cd ) and the uniaxial compressive strength (σ ucs ) was constructed. The results indicate that the normalized quantity σ cd /σ...

It was found that the crack damage stress threshold, σcd, is a phase transition point during the deformation process of rock and is equivalent to the unstable fixed point of renormalization group theory. Thus, a relationship exists between the renormalization group theory and the rock deformation process, through which we can investigate the critic...

Based on the brittle failure theory of multiple locked patches in a seismogenic fault system and the associated prediction method developed by us, we have released a medium- and long-term prediction of future strong earthquakes in the Yutian seismic zone of Xinjiang, including the magnitude, location, critical Benioff strain, and focal depth. Compa...

This paper reports the relationship between electrical resistivity and rock failure during uniaxial compression. Experiments of rock samples on an electro-hydraulic servo-controlled testing machine show that the variation of electrical resistivity is closely related to rock deformation. Near to rock fracture, microcracks appear and change the micro...

Based on the brittle failure theory of multiple locked patches in a seismogenic fault system and associated prediction method developed by us, the prediction results, including the magnitude, place, critical strain, and hypocentral depth of the oncoming strong earthquake for Yutian seismic zone have been published in advance. In comparison with the...