Experimental and Numerical Study of Failure Behavior and Energy Mechanics of Rock-Like Materials Containing Multiple Joints

Considering the deep mining heat-hazard problem, the concept and academic idea of cold load and storage (CLS) functional backfill applied on deep mine cooling was put forward. Firstly, according to characteristics of filling mining, a method of cooling stopes with CLS phase changing backfill which is made from the backfill material with CLS phase change material (PCM) was proposed. e working process, cooling physics, and the economic and safety benefits of CLS phase changing backfill were produced. Secondly, the theory system of cooling with CLS phase changing backfill was built. e theoretical basis of the key problems involved was investigated and analyzed which concluded heat transfer, fluid mechanics, and backfill mechanics. Lastly, the technology system of cooling with CLS phase changing backfill was established on the basis of the required technical assistance. It includes four parts: the backfill material design, the backfill material conveying way design, the stope temperature control scheme design, and the strength of cemented tailings backfill analysis. e idea of applying CLS phase changing backfill on cooling deep mine stopes and its theory and technology systems provide a scientific research and suitable development direction for deep mine cooling.

Section: Back Ll Mechanicsmentioning

confidence: 99%

Cold Load and Storage Functional Backfill for Cooling Deep Mine

Wang

Chen

Zhang

et al. 2018

“…Determining the microparameters for numerical simulation is di cult by experiment, but it is essential to establish a correlation between the macrobehavior and microparameters for validating the particle properties used in numerical specimens. e macrobehavior includes the stress-strain curve, peak stress, elastic modulus, and failure mode [27][28][29]. e trial and error method was used in con rming the microparameters.…”

Section: Con Rmation For Microparameters Of Rock-like Materialsmentioning

confidence: 99%

Numerical Investigation of Influences of Drilling Arrangements on the Mechanical Behavior and Energy Evolution of Coal Models

Zhao

Guo

et al. 2018

Destress drilling method is one of the commonly used methods for mitigating rock bursts, especially in coal mining. To better understand the influences of drilling arrangements on the destress effect is beneficial for rock burst mitigation. This study first introduced the rock burst mitigation mechanism of the destress drilling method and then numerically investigated the influences of drilling arrangements on the mechanical properties of coal models through uniaxial compression tests. Based on the test results, the energy evolution (i.e., the energy dissipation and bursting energy indexes) influenced by different drilling arrangements was analyzed. When the drilling diameter, the number of drilling holes in one row, or the number of drilling rows increases, the bearing capacity of specimens nonlinearly decreases, but the energy dissipation index increases. In addition, the drilling diameter or the number of drilling holes in one row affects the failure mode weakly, which is different from that of the number of drilling rows. Consequently, the bursting energy index decreases as increasing the drilling diameter or the number of drilling holes in one row, but as increasing the number of drilling rows, the variation law of bursting energy index is not obvious. At last, the influencing mechanism of drilling arrangement on the rock burst prevention mechanism of the destress drilling method was discussed and revealed.

“…Generally, the single shear strength criterion is used for the elastic-plastic mechanics solution of roadway surrounding rocks, such as the Mohr-Coulomb criterion or the HookBrown criterion [1][2][3][4][5]. Although the elastic-plastic failure of the roadway surrounding rocks can be considered as a plane strain problem, in the field engineering practice, the roadway surrounding rock is mostly in the triaxial compression state because of the distribution of residual stresses, the hinge of the fractured rock, and the existence of the supporting structure [6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Plastic Failure Analysis of Roadway Floor Surrounding Rocks Based on Unified Strength Theory

Zheng

2018

Taking the whole surrounding rock of an excavation roadway as the research object, the elastoplastic failure mechanics analysis of the surrounding rock body of the excavated roadway under three-directional in situ stresses is carried out by using the knowledge of generalized plane strain problems and unified strength theory, and the equations are derived for the elasticplastic zone stress together with the plastic fracture range of the roadway floor surrounding rock under three-directional in situ stresses. At the same time, by means of the conclusion of mechanical analysis and the results of in situ detection of in situ stress in the Changcun mining area, the stability of the roadway floor surrounding rock was analyzed. e analysis reveals the influence on the stability of the roadway floor surrounding rock between the spatial relationship with the different in situ stresses and the roadway layout; meanwhile, it calculates the range of the plastic failure zone and the stress value of the #1 roadway floor in the S6 mining area of Changcun mine, which provides a reliable theoretical mechanical reference for research on roadway floor heave control technology.