Modeling of Rock and Soil Aggregate under the Condition of Uniaxial Compression

2011 ◽  
Vol 243-249 ◽  
pp. 55-60
Author(s):  
Jian Ming He ◽  
Xiao Li ◽  
Teng Fei Li ◽  
Shou Ding Li
Keyword(s):  
Uniaxial Compression ◽  
Mechanical Response ◽  
Structural Characteristics ◽  
Failure Process ◽  
Soil Aggregate ◽  
Deformation And Failure ◽  
Uniaxial Test ◽  
Soft Matrix ◽  
Rock Fragments ◽  
Rock And Soil

Rock and soil aggregate (RSA) is a special geo-material and composed of hard matrix like gravel, cobble, pebble and soft matrix of soil. Discontinuity and heterogeneity are the main characteristics of RSA and its mechanical response is mainly controlled by its complex internal structure. The rock fragments play very important role in the mechanical performances under the condition of uniaxial compression and the rock content (the volume percent of rock fragments in RSA) of RSA is the focus of this study. RSA models with different rock content based on the structural characteristics were built for the numerical uniaxial test. The strength of RSA decreases instead with the increment of rock contents, stress-strain curves attained in the test reflect five different phases according to the deformation and failure process of samples.

scholarly journals Research on image recognition method of rock and soil porous media based on dithering algorithm

2021 ◽  
Vol 283 ◽  
pp. 01025
Author(s):  
Hao Zhang ◽  
Hewen Liu ◽  
Jinyong Bai
Keyword(s):  
Porous Media ◽  
Internal Structure ◽  
Digital Image ◽  
Mechanical Response ◽  
Failure Process ◽  
Soil Mass ◽  
Recognition Method ◽  
Multiple Parameters ◽  
Composition And Structure ◽  
Rock And Soil

Rock-soil mass is a kind of material with complex internal structure, and its macro-mechanical response and failure process are influenced by internal microscopic composition and structure. Based on the research results of digital image technology in quantitative aspects of internal structure of rock and soil, a method for segmentation of rock and soil pore images based on dithering algorithm and statistical method for multiple parameters of pores is proposed in this paper. The result of verification shows that the pore recognition method proposed in this paper is reliable, can obtain the pore distribution and related parameters quickly and effectively, which has certain academic value and research significance.

Uniaxial Compression with Acoustic Emission Experimental Study on Rock Damage Process

2012 ◽  
Vol 204-208 ◽  
pp. 173-176
Author(s):  
Jing Hong Liu ◽  
Xiao Hua Liu ◽  
Wen Han
Keyword(s):  
Acoustic Emission ◽  
Crack Propagation ◽  
Uniaxial Compression ◽  
Failure Process ◽  
Structure Stability ◽  
Uniaxial Compression Test ◽  
Concrete Material ◽  
Deformation And Failure ◽  
Disaster Assessment ◽  
Contrast Analysis

Acoustic emission technique is an important technique for monitoring crack propagation and failure process of rock, coal and concrete material. A uniaxial compression test with acoustic emission monitoring on coal and rock samples’ deformation and failure process were carried out. Failure precursor information of rock, coal and concrete material were studied through contrast analysis the experiment result include acoustic emission signals, strain, load correlation of sample inner crack propagation to failure process. The test provided necessary data to further understand on rock burst failure disaster. The test result provides a theoretical basis for further application of acoustic emission for prediction coal rock dynamic disaster, assessment rock and concrete structure stability and study rock concrete material failure process mechanism.

scholarly journals Research on Supporting Method for High Stressed Soft Rock Roadway in Gentle Dipping Strata of Red Shale

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 423
Author(s):  
Chunde Ma ◽  
Jiaqing Xu ◽  
Guanshuang Tan ◽  
Weibin Xie ◽  
Zhihai Lv
Keyword(s):  
Failure Process ◽  
High Stress ◽  
Soft Rock ◽  
In Situ Stress ◽  
Mechanical Parameters ◽  
Deformation And Failure ◽  
Deep Mine ◽  
Plastic Energy ◽  
Roadway Stability ◽  
Phosphate Mine

Red shale is widely distributed among the deep mine areas of Kaiyang Phosphate Mine, which is the biggest underground phosphate mine of China. Because of the effect of various factors, such as high stress, ground water and so on, trackless transport roadways in deep mine areas were difficult to effectively support for a long time by using traditional supporting design methods. To deal with this problem, some innovative works were carried out in this paper. First, mineral composition and microstructure, anisotropic, hydraulic mechanical properties and other mechanical parameters of red shale were tested in a laboratory to reveal its deformation and failure characteristics from the aspect of lithology. Then, some numerical simulation about the failure process of the roadways in layered red shale strata was implemented to investigate the change regulation of stress and strain in the surrounding rock, according to the real rock mechanical parameters and in-situ stress data. Therefore, based on the composite failure law and existing support problems of red shale roadways, some effective methods and techniques were adopted, especially a kind of new wave-type bolt that was used to relieve rock expansion and plastic energy to prevent concentration of stress and excess deformation. The field experiment shows the superiorities in new techniques have been verified and successfully applied to safeguard roadway stability.

Experimental Analysis of Ratcheting Failure Based on the Piezomagnetic Response of X80 Pipeline Steel

2017 ◽  
Author(s):  
Sheng Bao ◽  
Shengnan Hu ◽  
Yibin Gu
Keyword(s):  
Magnetic Field ◽  
Hysteresis Loop ◽  
Mechanical Response ◽  
Pipeline Steel ◽  
Failure Process ◽  
Failure Behavior ◽  
X80 Pipeline Steel ◽  
Test Analysis ◽  
Number Of Cycles ◽  
The Magnetic Field

The objective of this research is to explore the correlation between the piezomagnetic response and ratcheting failure behavior under asymmetrical cyclic stressing in X80 pipeline steel. The magnetic field variations from cycle to cycle were recorded simultaneously during the whole-life ratcheting test. Analysis made in the present work shows that the piezomagnetic hysteresis loop evolves systematically with the number of cycles in terms of its shape and position. Corresponding to the three-stage process in the mechanical response, piezomagnetic response can also be divided into three principal stages, but the evolution of magnetic parameter is more complex. Furthermore, the loading branch and unloading branch of the magnetic field-stress hysteresis loop separate gradually from each other during ratcheting failure process, leading to the shape of hysteresis loop changes completely. Therefore, the progressive degradation of the steel under ratcheting can be tracked by following the evolution of the piezomagnetic field. And the shape transition of the hysteresis loop can be regarded as an early warning of the ratcheting failure.

Failure Process of Rock Sample Observed by AE Source Locating Technique under Uniaxial Compression

2006 ◽  
Vol 324-325 ◽  
pp. 567-570
Author(s):  
Yuan Hui Li ◽  
Rui Fu Yuan ◽  
Xing Dong Zhao
Keyword(s):  
Uniaxial Compression ◽  
High Speed ◽  
Failure Process ◽  
Compression Tests ◽  
Temporal And Spatial Distribution ◽  
Primary Stage ◽  
Brewing Process ◽  
Ae Signal ◽  
Failure Location ◽  
Low Amplitude

A series of uniaxial-compression tests were conducted on some representative brittle rock specimens, such as granite, marble and dolerite. A multi-channel, high-speed AE signal acquiring and analyzing system was employed to acquire and record the characteristics of AE events and demonstrate the temporal and spatial distribution of these events during the rupture-brewing process. The test result showed that in the primary stage, many low amplitude AE events were developed rapidly and distributed randomly throughout the entire specimens. In the second stage, the number of AE increased much slower than that in the first stage, while the amplitude of most AE events became greater. Contrarily to the primary stage, AE events clustered in the middle area of the specimen and distributed vertically conformed to the orientation of compression. The most distinct characteristic of this stage was a vacant gap formed approximately in the central part of the specimen. In the last stage, the number of AE events increased sharply and their magnitude increased accordingly. The final failure location coincidently inhabited the aforementioned gap. The main conclusion is that most macrocracks are developed from the surrounding microcracks existed earlier and their positions occupy the earlier formed gaps, and the AE activity usually becomes quite acute before the main rupture occurs.

Mechanical Response of BNNS-reinforced Aluminum Composites under Uniaxial Compression

2021 ◽  
Author(s):  
Jinming Li ◽  
Yuhua Huang ◽  
Baoshan Zeng ◽  
Chenzefang Feng ◽  
Fulong Zhu
Keyword(s):  
Uniaxial Compression ◽  
Mechanical Response ◽  
Aluminum Composites

Numerical Analysis of Faults on Deep-Buried Tunnel Surrounding Rock Damaged Zones

2011 ◽  
Vol 90-93 ◽  
pp. 74-78 ◽  
Author(s):  
Jun Hu ◽  
Ling Xu ◽  
Nu Wen Xu
Keyword(s):  
Numerical Analysis ◽  
Mechanical Response ◽  
Progressive Failure ◽  
Process Analysis ◽  
Failure Process ◽  
Water Inrush ◽  
Surrounding Rock ◽  
Factors Affecting ◽  
Rock Failure Process ◽  
Tunnel Instability

Fault is one of the most important factors affecting tunnel instability. As a significant and casual construction of Jinping II hydropower station, when the drain tunnel is excavated at depth of 1600 m, rockbursts and water inrush induced by several huge faults and zone of fracture have restricted the development of the whole construction. In this paper, a progressive failure progress numerical analysis code-RFPA (abbreviated from Rock Failure Process Analysis) is applied to investigate the influence of faults on tunnel instability and damaged zones. Numerical simulation is performed to analyze the stress distribution and wreck regions of the tunnel, and the results are consistent with the phenomena obtained from field observation. Moreover, the effects of fault characteristics and positions on the construction mechanical response are studied in details. Some distribution rules of surrounding rock stress of deep-buried tunnel are summarized to provide the reasonable references to TBM excavation and post-support of the drain tunnel, as well as the design and construction of similar engineering in future.

scholarly journals Deformation and failure characteristics of weathered granite under uniaxial compression

AIP Advances ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 075222 ◽  
Author(s):  
Lingfan Zhang ◽  
Duoxing Yang ◽  
Zhonghui Chen
Keyword(s):  
Uniaxial Compression ◽  
Failure Characteristics ◽  
Deformation And Failure ◽  
Weathered Granite
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