Hongran Chen

Chinese Academy of Sciences | CAS · Institute of Geology and Geophysics

Locked segment-dominated landslides initiate when locked segments are sufficiently damaged to be unlocked. The evolution of such slopes toward instability displays either an exponentially or stepwise accelerated displacement pattern, but the underlying mechanisms of these patterns are elusive. We show that the displacement pattern is governed by me...

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...

A reliable evaluation method for the fracability (i.e., ability to generate abundant cracks) of reservoir rocks is a critical issue for maximum hydraulic fracturing efficiency. Most previous fracability indices lacked enough rationality and practicability, and thus could not consistently provide a reliable evaluation. We suggest a new fracability i...

Hydraulic fracturing for oil-gas and geothermal reservoir stimulation is closely related to the propagation of Mode I crack. Nonlinear deformation due to rock heterogeneity occurs at such crack tips, which causes the fracture process zone (FPZ) to form before the crack propagates unsteadily. However, the relationship between the FPZ characteristics...

Hydraulic fracturing for oil-gas and geothermal reservoir stimulation is closely related to the generation and propagation of Mode I crack. Nonlinear deformation due to rock heterogeneity occurs at such crack tip, which causes the fracture process zone (FPZ) to form before the crack propagates unsteadily. However, the relationship between the FPZ c...

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...

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...

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...

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...

The bedding orientation influences the failure pattern and brittleness of shale. Clarifying the relation between acoustic emission and the effects of bedding orientation on the failure behaviors of shale is important to understand the mechanism of the formation of fracture networks. In this study, we analyzed the failure patterns and crack complexi...

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...

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...

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...

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...

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...

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...

As the weak part in shale formations, the bedding plane is an important element affecting the stability of boreholes and the formation of hydraulic fracture networks. To study the influence of bedding plane on the progressive failure process of rock, a series of uniaxial compressive tests were conducted on shale samples with bedding plane orientati...