Control Technology and Application for Surrounding Rock Deformation in T-Junction Area of Gob-Side Entry Retaining

2013 ◽  
Vol 838-841 ◽  
pp. 1873-1879 ◽  
Author(s):  
Chang Liang Han ◽  
Nong Zhang ◽  
Bao Yu Li
Keyword(s):  
Abutment Pressure ◽  
Main Roof ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Control Technology ◽  
Support Design ◽  
Junction Area ◽  
Pressure Zone ◽  
Stress Zone ◽  
Surrounding Rock Deformation

On the bases of theoretic analysis, numerical simulation, and project practice, stress distribution of surrounding rock and movement characteristics of roof strata in T-junction area of gob-side entry were analyzed. Besides, control technology in T-junction area was proposed after indicating deformation characteristics of different stages in gob-side entry. Results show that there is an inclined block in T-junction area after fracture of main roof and the period when the block is tending to stability is a critical stage of pressure appearance for gob-side entry. Further, three stress zones: in-situ stress zone, abutment pressure zone and low stress zone appear in both strike and dip of mining panel and enhanced support of gob-side entry before excavation should keep away from the abutment pressure zone, which also indicates that deep bolting support can exert the bearing capacity of deep rock mass. Additionally, the whole procedure of surrounding rock deformation can be divided into four stages and deformation in gob-side entry is larger than that of entry excavation, which means that efficient support design should be taken into account. Ultimately, district control technologies for surrounding rock of gob-side entry in back zone, filling zone, and front zone are proposed and it showed a good adaption in project practice of coalmine.

Concrete Crack Control Technology in Chongqing Inch Container Terminal Box Letter of Application in Engineering

2012 ◽  
Vol 217-219 ◽  
pp. 161-164
Author(s):  
Ya Nan Fu ◽  
Ze Ping He
Keyword(s):  
Container Terminal ◽  
Steel Corrosion ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Control Technology ◽  
Crack Control ◽  
Concrete Crack ◽  
Box Culverts ◽  
And Control ◽  
Surrounding Rock Deformation

This paper mainly introduces the main causes of the concrete cracks, and with Chongqing inch beach bonded port freight container terminal, drain tank letter concrete crack control as the engineering example, the paper analyzes the method of crack control. For example reduce water consumption, choose the narrow fly ash cement, reduce the narrow concrete constraint, and control the hydration heat, strengthen the concrete curing, control the steel corrosion of crack, control the box by letter of the surrounding rock deformation, they can be reached that box culverts basic don't crack effect.

Research on Supporting Technology of Roadway Driving along Next Goaf of Second Mining Strip Pillar

2012 ◽  
Vol 446-449 ◽  
pp. 1657-1660
Author(s):  
Wei Dong Lv ◽  
Nan Nan Zhao
Keyword(s):  
Abutment Pressure ◽  
High Strength ◽  
Main Roof ◽  
Surrounding Rock ◽  
Control Effect ◽  
General Stability ◽  
High Strength Bolt ◽  
Mining Face ◽  
The Stability ◽  
Surrounding Rock Deformation

For roadway driving along next goaf of strip pillar second mining, being influenced by the abutment pressure of previous coal mining face and main roof breaking rotary deformation, the surrounding rock deformation is serious and the control effect of ordinary bolt supporting on the general stability of roadway driving along next goaf is poorer. According to the concrete geological and technique condition of the 2351 second mining strip pillar in Daizhuang Colliery, adopting the united support pattern combined high strength bolt of levorotatory continuous thread and anchor of low relaxation prestress, the safety of the roadway can be ensured and the stability of the roadway surrounding rocks can be improved. It is of significant reference meaning for bolting support of roadway driving along next goaf of second mining strip pillar under similar condition.

scholarly journals Surrounding rock deformation and stress evolution in pre-driven longwall recovery rooms at the end of mining stage

2019 ◽  
Vol 6 (4) ◽  
pp. 536-546 ◽  
Author(s):  
Bonan Wang ◽  
Faning Dang ◽  
Wei Chao ◽  
Yanping Miao ◽  
Jun Li ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Recovery Room ◽  
Coal Pillar ◽  
Main Roof ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Stress Evolution ◽  
The Face ◽  
Surrounding Rock Deformation

Abstract Two case studies were conducted in the Shennan mining area of Shaanxi Province, China to evaluate the surrounding rock deformation and stress evolution in pre-driven longwall recovery rooms. These studies mainly monitored the surrounding rock deformation and coal pillar stress in the recovery rooms of the N1206 panel of 2−2 coal seam at Ningtiaota Coal Mine and the 15205 panel of 5−2 coal seam at Hongliulin Coal Mine. The monitoring results showed that the surrounding rock deformation of the main recovery room and the coal pillar stress in the N1206 and 15205 panels began to increase significantly when the face was 36 m and 42 m away from the terminal line, respectively. After the face entered the main recovery room, the maximum roof-to-floor convergence in the N1206 and 15205 panels was 348.03 mm and 771.24 mm, respectively, and the coal pillar stresses increased more than 5 MPa and 7 MPa, respectively. In addition, analysis of the periodic weighting data showed that the main roof break position of the N1206 and 15205 panels after the longwall face entered the main recovery room was − 3.8 m and − 8.2 m, respectively. This research shows that when the main roof breaks above the coal pillar, the surrounding rock deformation of the main recovery room and the coal pillar stress increase sharply. The last weighting is the key factor affecting the stability of the main recovery room and the coal pillar; main roof breaks at disadvantageous positions are the main cause of the support crushing accidents.

Analysis for Surrounding Rock Instability and Research for Stability Control Technology in Underground Engineering

2012 ◽  
Vol 170-173 ◽  
pp. 1367-1371 ◽  
Author(s):  
Xian Kai Bao ◽  
Yi Li
Keyword(s):  
Damage Mechanism ◽  
Stability Control ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Control Technology ◽  
Rock Damage ◽  
Underground Excavation ◽  
Underground Engineering ◽  
Surrounding Rock Deformation ◽  
Made In

Aiming at the surrounding damage and instability in underground excavation and operation, an analysis of surrounding rock damage modes and an exploration of damage mechanism are done and an conclusion of control principles and means for surrounding rock deformation and damage is made in the thesis. The result dovetailed with engineering and provides reference for engineering design and operation.

scholarly journals Model Test and Numerical Study on Surrounding Rock Deformation and Overburden Strata Movement Law of Gob-Side Entry Retaining via Roof Cutting

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 458 ◽  
Author(s):  
Daoyong Zhu ◽  
Jiong Wang ◽  
Weili Gong ◽  
Zheng Sun
Keyword(s):  
Model Test ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Shanxi Province ◽  
Beam Model ◽  
Physical Test ◽  
Strata Movement ◽  
Deformation Equation ◽  
Surrounding Rock Deformation ◽  
Overlying Strata

The effects of roof cutting techniques on the movement law of the overlying strata and deformation features of the surrounding rock in gob-side entry retaining mines were studied using 200 working faces of the Dianping coal mine in Shanxi Province. Using a mechanical analysis, a cantilever beam model formed by roof cutting was used to derive a deformation equation. The physical model test based on the field prototype revealed an asymmetrically distributed displacement curve and reduced collapse displacement when the rock stratum was far from the cutting seam. Outside of the roof cutting height, the collapse of the overlying strata gradually reached a symmetric distribution with increasing height. The deformation of the retained roadway was mainly concentrated on the roof, and the maximum deformation was 14 mm near the roof cutting side. A numerical simulation of the original size of the model test proved that the laws of strata movement and surrounding rock deformation were consistent with the physical test results. Finally, field measurements were performed, which verified the rationality of this study.

scholarly journals Deformation Rules for Surrounding Rock in Directional Weakening of End Roofs of Thin Bedrocks and Ultrathick Seams

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Fei Liu ◽  
Zhanguo Ma ◽  
Yongsheng Han ◽  
Zhimin Huang
Keyword(s):  
Abutment Pressure ◽  
Main Roof ◽  
Stability Control ◽  
Surrounding Rock ◽  
Western China ◽  
Resource Exploitation ◽  
Failure Characteristics ◽  
Key Strata ◽  
Working Face ◽  
Geological Conditions

With the deployment of China’s energy strategy in the western regions, complex geological mining conditions such as thin bedrock and ultrathick seams in western China have caused a series of problems such as serious deformation of the surrounding rock at the ends of the working face and the increase in the lead abutment pressure of the roadways; the research on end roof deformation in the resource exploitation in western China has become one of the great demands of the industry. Based on the failure characteristics of rock mass, relying on the actual mining geological conditions of a coal mine in Inner Mongolia, the failure characteristics of the overlying rock strata under the influence of mining were simulated and analyzed using similar material simulation experiment, which intuitively reproduced the failure and deformation processes of the immediate roof, main roof, and key strata and revealed the mechanical mechanism of the directional weakening of the end roof. It is of great significance for the stability control of the surrounding rock at the end of the fully mechanized caving face in the thin bedrocks and ultrathick seams, reducing the abutment pressure of gate roadway and controlling the spontaneous combustion of residual coal in the goaf.

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