An Electro Breakdown Damage Model for Granite and Simulation of Deep Drilling by High-Voltage Electropulse Boring by Changping Li, Longchen Duan, Songcheng Tan, Victor Chikhotkin, Xiaohui Wang

“…Electropulse rock breaking has wide application prospects in hard rock drilling and ore breaking. At present, there are no suitable physical mathematical models that describe electropulse boring (EPB) processes under confining pressures. …”
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Formation Mechanism and Stability Analysis of the Hejia Landslide by Hao Zhang, Zaiqiang Hu, Xingzhou Chen, Hongru Li

“…Through field investigation and analysis of regional geological conditions, it is concluded that Hejia landslide is a large-scale landslide, through long-term sliding-bending deformation; it is generated from the external hard rock with thick layers and sliding zone for layered soft rock; the formation mechanism of landslide is as follows: (1) high-steep and hard-soft layered slope is the slope structure condition that caused the large landslide; (2) the existence of thick soft rock belt provides material conditions for the formation of slip surface; (3) certain air conditions provide displacement space for the separation and disintegration of the sliding body, and the landslide is stable at present. …”
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Study on the abrasion property of the anvil inside a hydraulic DTH hammer fitted with horizontal oriented sliders by Jiang-fu He, Qi-lei Yin, Kun Yin

“…Hydraulic hammers have been extensively applied to horizontal directional well drilling in hard rock formations. However, the service life of a hydraulic hammer is still unsatisfactory due to the heavy wear or abrasion of the horizontal anvil, which leads to the failure and the reduction of service life in directional well drilling. …”
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Experimental investigation on rock fragmentation charactersitics of pressurized pulsed water jet by Yuanfei Ling, Xiaoqiang Wang, Jiren Tang, Yangkai Zhang

“…The erosion volume of granite is much larger than that of sandstone, indicating that PPWJ-induced fragmentation of brittle and hard rock is more likely to form large-volume spalling. …”
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Influence of Support Stiffness on Dynamic Characteristics of the Hydraulic Pipe Subjected to Basic Vibration by Wei Qu, Huailiang Zhang, Wei Li, Wenqian Sun, Lina Zhao, Haihui Ning

“…The basic vibration generated during the tunneling process of hard rock tunnel results in the change of the support stiffness of the hydraulic pipe, which causes the problem of reduction of pipe transmission efficiency. …”
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Prediction correction modeling of water-conducting fracture zones height due to repeated mining in close distance coal seams by Zhuoran Kang, Daming Yang, Pengfei Shen

“…This study compiles extensive measured data from various mining areas in China to analyze the coupling relationship between the WCFZ development height and six influencing factors: mining thickness, mining depth, coal seam spacing, hard rock lithology ratio, and the slope length of working face. …”
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Experimental Study on Mechanical Properties of Deep Buried Granite under Different Confining Pressures by Jun Zhao, Tan Zhang

“…Brittle failure of hard rock poses a serious threat to the stability of surrounding rock in deep underground engineering. …”
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Numerical Simulation of Conical Pick Cutting Arc Rock Plate Fracture Based on ANSYS/LS-DYNA by Zhiwen Wang, Qingliang Zeng, Zhenguo Lu, Lirong Wan, Xin Zhang, Guanshun Gao

“…The new method of rock breaking based on the combination of circular sawblade and conical pick was proposed to improve the effectiveness of hard rock breaking. The numerical simulation method was applied to research the conical pick cutting arc rock plate by ANSYS/LS-DYNA. …”
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Determination of Shape Coefficient in Elastic Modulus Estimation with Penetration Test by Tongbin Zhao, Rui Mao, Kai Fang, Biwen Zhang, Fenghai Yu

“…The shape coefficient of hard rock is higher than that of soft rock. Shape coefficient should be selected reasonably according to the penetration depth in practical application, and the reason, furthermore, why back-calculated shape coefficient deviates from the theoretical value is also discussed.…”
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Research on Cutting Characteristics of Rock Plate with Two Sides Fixed and Two Sides Free by Zhenguo Lu, Qingliang Zeng, Zhihai Liu, Guanshun Gao, Peisi Zhong

“…Conical pick wear is an urgent problem in the roadway excavation caused by hard rock difficult to break. The traditional method of increasing cutting power to improve cutting performance of conical pick significantly increases pick wear. …”
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Study on Dynamic Constitutive Model of Weakly Consolidated Soft Rock in Western China by Lei Wang, Hongming Su, Yue Qin, Shiguan Chen

“…It was also found that the constitutive equation was applicable to express the dynamic mechanical properties of rock-like materials such as hard rock, soft rock, frozen soil, raw coal, and concrete. …”
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Evaluating the Impact of Blast-Induced Damage on the Rock Load Supported by Liner in Construction of a Deep Shaft: A Case Study of Ventilation Shaft of Micangshan Road Tunnel Proje... by Yong Fang, Zhigang Yao, Gabriel Walton, Jian Zhou, Wanghao Xu, Yuchao Zheng

“…This study focuses on quantifying the magnitude and distribution of the radial loads on the lining of a deep shaft constructed in hard rock by the so-called short-step method. The blasting-induced damage zone (BDZ) around the shaft was characterized using ultrasonic testing and incorporated into the convergence-confinement method (CCM) and 3D numerical analyses to assess the impact of BDZ on rock loading against the liner. …”
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Simulation and Analysis of a Split Drill Bit for Pneumatic DTH Hammer Percussive Rotary Drilling by Yuanling Shi, Conghui Li

“…Reverse circulation impact drilling has the advantages of high drilling efficiency and less dust, which can effectively form holes in hard rock and gravel layer. As integral reverse circulation drill bits used in the conventional down-the-hole (DTH) hammers are only suitable for specific formations, the whole set of DTH hammer needs to be replaced when drilling different formations. …”
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Assessment of Surface Runoff for Tank Watershed in Tamil Nadu Using Hydrologic Modeling by Marykutty Abraham, Riya Ann Mathew

“…The study area is Urapakkam watershed with a chain of 3 tanks having an aerial extent of 4.576 km2 with hard rock formation underneath and thus has limited scope for groundwater recharge. …”
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Application of Presplitting Blasting Technology in Surrounding Rock Control of Gob-Side Entry Retaining with Hard Roof: A Case Study by Shuang Gong, Yi Tan, Yunpeng Liu, Dan Zhu, Yang Yu

“…The comprehensive control measures for the surrounding rock of 7135 roadway with roof cutting and pressure relief and gob retaining are formulated, including safety assurance technical measures, such as advanced precrack and seam cutting, roof reinforcement and support, gangue retaining protection beside the roadway, lagging temporary support, and on-site industrial test monitoring scheme. Aiming at the hard rock roof, the “deep hole + shallow hole” presplitting blasting roof cutting technology is developed, and the economic and reasonable blasting parameters are determined. …”
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Experimental Evaluation of Multiple Frost Heaving Parameters for Preflawed Granite in Beizhan Iron Mining, Xinjiang, China by Yu Wang, Dayu Long, Zulifeiya Rejuti, Huajian Wang

“…The sensitivity analysis reveals the influential order of the considered factors to peak FHF, which is the rock lithology, flaw width, flaw cement type, and flaw length. For low-porosity hard rock, increasing flaw width, flaw length, and flaw cement strength can improve the probability of frost heaving failure. …”
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Numerical Investigation of the Influence of Roof Fracturing Angle on the Stability of Gob-Side Entry Subjected to Dynamic Loading by Zhibiao Guo, Lei Zhang, Zhibo Ma, Feixiang Zhong, Jingchao Yu, Siming Wang

“…Furthermore, dynamic loading was applied to research the influence of fracture of hard rock strata on the entry stability. The global model was validated with the field data. …”
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Study of SCA-Induced Rock Crack Propagation under Different Stress Conditions Using a Modified Cohesive Element Method by Shen Wang, Hani Mitri, Huamin Li, Dongyin Li, Wen Wang

“…When inducing cracks, soundless cracking agents (SCAs) do not generate vibration, harmful gas, dust, nor flying rock fragment, making them suitable for hard rock roof breaking, rock burst prevention, oil or gas reservoir stimulation, and building demolition. …”
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Seismic Responses and Damage Mechanisms of Deep-Buried Underground Powerhouse in Layered Rock Mass by Meng Zhao, Ming Xiao, Juntao Chen, Hancheng Jin

“…After considering the dynamic contact, the obvious seismic deterioration effect and interlaminar dislocation displacement occur between soft and hard rock, and the sidewalls suffer more severe deterioration degree than the top arch. …”
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A New Evaluation Method for the Uniaxial Compressive Strength ahead of the Tunnel Face Based on the Driving Data and Specification Parameters of TBM by Yuexiu Wu, Chishuai Ma, Xianjun Tan, Dianseng Yang, Hongming Tian, Jianping Yang

“…To describe the relationships of UCS with PLSI of the Murree tertiary hard rocks, regression analyses have been conducted and a fitting equation with high-prediction performance was developed. …”
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