Method for Measuring Rock Mass Characteristics and Evaluating the Grouting-Reinforced Effect Based on Digital Drilling

Wang, Qi; Gao, Hongke; Yu, Hao; Jiang, Bei; Liu, Bohong

doi:10.1007/s00603-018-1624-9

Cited by 89 publications

(26 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The complete mechanical parameters of rock mass near the chamber were obtained through experiment, as shown in Table . There are a large number of irregular joints and fissures in the chamber surrounding rocks, so the rock mass parameters measured in the experiment were higher than the strength of rock mass at the stope . To simulate the strength reduction, Hoek and Bra proposed the generalized Hoek‐Brown criterion.…”

Section: The Surrounding Rock Failure Characteristics During the Excamentioning

confidence: 99%

“…There are a large number of irregular joints and fissures in the chamber surrounding rocks, so the rock mass parameters measured in the experiment were higher than the strength of rock mass at the stope. 16 To simulate the strength reduction, Hoek and Bra proposed the generalized Hoek-Brown criterion. The specific expression is as follows 17,18 : where σ 1 is the maximum principal stress; σ 3 is the minimum principal stress; m b is a reduced value (for the rock mass) of the material constant m i (for the intact rock); s and a are constants which depend upon the characteristics of the rock mass; σ ci is the uniaxial compressive strength (UCS) of the intact rock pieces.…”

Section: Rock Mass Strength Criterion At the Stopementioning

confidence: 99%

See 1 more Smart Citation

Failure characteristics and control technology for large‐section chamber in compound coal seams—A case study in Tashan Coal Mine

Tai

Xia

Kuang

2019

Energy Science & Engineering

View full text Add to dashboard Cite

The coal production exploited from extra‐thick coal seams accounts for 45% of China's total coal production. With large coal output, the extra‐thick coal seams require that the chamber section be more than 100 m2. In case of parting (the noncoal rock, usually mudstone, sandwiched in the coal seam) in the extra‐thick coal seams, the integrity of the coal seams will be damaged and the large‐section chamber is extremely easy to occur rib spalling and roof leakage, which will increase the chamber's supporting difficulty. To solve such problems, this paper took the electromechanical chamber in Tashan Coal Mine as the engineering background and analyzed the deformation and failure characteristics of this chamber surrounding rocks by the numerical simulation method during the excavation process. The results indicated that the failure areas of surrounding rocks were mainly in partings, chamber ribs, and chamber dome with the failure depths of 15 m, 10 m, and 5 m, respectively. Based on the obtained deformation and failure characteristics, the supporting method of grouting integrated with high‐strength bolts and anchor cables was put forward. The grouting method was firstly used to improve the integrity of the chamber surrounding rocks, and the high‐strength bolts and anchor cables were used for supporting. Then, the supporting parameters of the bolts and anchor cables and the grouting parameters were optimized by the numerical simulation method. The optimized parameters were applied in the electromechanical chamber in Tashan Coal Mine, and the on‐site chamber ribs lateral displacement and roof separation amounts were only 0.018 m and 0.012 m, respectively, indicating that the surrounding rocks were controlled effectively.

show abstract

Section: The Surrounding Rock Failure Characteristics During the Excamentioning

confidence: 99%

Section: Rock Mass Strength Criterion At the Stopementioning

confidence: 99%

Failure characteristics and control technology for large‐section chamber in compound coal seams—A case study in Tashan Coal Mine

Tai

Xia

Kuang

2019

Energy Science & Engineering

View full text Add to dashboard Cite

show abstract

“…The roof of the gob is automatically degraded along the slit surface due to its self‐weight and mine pressure, thus retaining a slot in the working surface which can be used as a mining roadway for the adjacent working face in the future. The cutting roof and release pressure mining technology has changed the layout of the traditional longwall mining side and the double‐district roadway, creating a new method of digging a single lane . A comparison of the cutting roof and release pressure mining and the traditional longwall mining is shown in Figure …”

Section: Principle Of the Cutting Roof And Release Pressure Mining Tementioning

confidence: 99%

Evolution and application of airflow permeability characteristics of gob in roof cutting and pressure releasing mining method

Chen

Wang

et al. 2020

Energy Science & Engineering

View full text Add to dashboard Cite

Cutting roof and release pressure technology has changed the pressure transmission mode of the roof and the caving characteristics of roof rock, which in turn has changed the permeability evolution of the gob. To obtain the permeability characteristics of the gob for the roof cutting and pressure releasing mining method, a mathematical model for the gob voidage and permeability was established by analyzing the overlying strata movement law and the lateral stress variation in the gob. The airflow migration law of haulage roadway 12 201 in Halagou coal mine was studied using Fluent software and an established mathematical model. The main conclusions obtained are as follows: The overburden pressure and lateral stress in the gob gradually increase with the advancement of the working face; along the direction of the retaining roadway, there are two roadway windflows entering the critical zones (the 22-100 m and 390-398 m sections). The inflow at these two sections accounted for 59% of the total air inflow, of which the most critical is the 28-53 m section, which accounts for 43% of the total air inflow in the two severe air leakage sections. The findings of this work provide a theoretical basis for the implementation of antileakage technology in the gob under the roof cutting and pressure releasing mining method and help reduce the risk of spontaneous combustion in the gob. K E Y W O R D Scaving characteristics of roof rock, cutting roof and release pressure, gob, voidage and permeability model 2074 |

show abstract

“…Roadway stability is important for safe mining [23][24][25]. He et al (2017) [26] proposed a technology of directional blasting fracturing to improve roadway stability.…”

Section: Introductionmentioning

confidence: 99%

Directional Blasting Fracturing Technology for the Stability Control of Key Strata in Deep Thick Coal Mining

et al. 2019

View full text Add to dashboard Cite

Under the conditions of high ground stress and mining disturbance, the strata breakage that is induced by mining is severe. Thus, it is critical to investigate the structural characteristics of key strata (KS) in deep thick mining. This study introduces an innovative technology, namely, directional blasting fracturing, in which an energy-gathering tube is installed in a borehole and an explosive is detonated to break the roof in a specified direction. A theory of balanced bulk filling is established based on the requirements of developing a voussoir beam structure, which can be used to effectively evaluate the percentage of bulk filling in gob and to determine to which structure the key strata belongs. Based on this theory, two types of novel structural models in the advancing and lateral directions of the longwall face are established and defined for studying the roof fracturing mechanism. Compared with a cantilever structure, Model C can develop a stable voussoir beam structure, limiting the rotation space of the KS and reducing both the peak abutment pressure and the dynamic disturbance time in the advancing of the longwall face. Model E is defined as when the technology of directional blasting fracturing effectively cuts a stress transfer path into the barrier pillar. The peak abutment pressures on the barrier pillar and auxiliary entry are smaller, and the dynamic disturbance time is shorter, which can effectively improve the stability of the auxiliary entry. The key parameters of directional blasting fracturing are designed and constructed, and they include the roof fracturing height, angle, and charge structure. The field application performance of this innovative technology at the longwall face of 3−1101 in Hongqinghe coal mine was evaluated by analyzing the chock pressure stress, the pillar pressure stress, and the deformation of the auxiliary entry during mining, which lays a foundation for the application of this technology in coal mines in China.

show abstract

Method for Measuring Rock Mass Characteristics and Evaluating the Grouting-Reinforced Effect Based on Digital Drilling

Cited by 89 publications

References 19 publications

Failure characteristics and control technology for large‐section chamber in compound coal seams—A case study in Tashan Coal Mine

Failure characteristics and control technology for large‐section chamber in compound coal seams—A case study in Tashan Coal Mine

Evolution and application of airflow permeability characteristics of gob in roof cutting and pressure releasing mining method

Directional Blasting Fracturing Technology for the Stability Control of Key Strata in Deep Thick Coal Mining

Contact Info

Product

Resources

About