scholarly journals Study on Stress Field Distribution Characteristics under Coal Seam Pre-splitting Blasting

2014 ◽  
Vol 84 ◽  
pp. 913-919 ◽  
Author(s):  
WANG Zhiliang ◽  
CHEN Xuexi ◽  
XING Shuren
Keyword(s):  
Stress Field ◽  
Coal Seam ◽  
Field Distribution ◽  
Distribution Characteristics

scholarly journals Numerical Simulation Research on Distribution Characteristics of Overlying Rock Stress Field in Floor Roadway

2021 ◽  
Vol 257 ◽  
pp. 03024
Author(s):  
Zhonghua Wang
Keyword(s):  
Stress Field ◽  
Field Distribution ◽  
Theoretical Basis ◽  
Surrounding Rock ◽  
Horizontal Distance ◽  
Distribution Characteristics ◽  
Rock Stress ◽  
Simulation Research ◽  
Location Selection ◽  
Coal Roadway

In order to explore the distribution characteristics of the overlying rock stress field in the floor roadway at different locations, FLAC3D software was used to simulate and analyze the surrounding rock directly above the floor roadway and the surrounding rock within 15m on both sides of the floor roadway when the distance between the floor roadway and the coal roadway and the horizontal distance were changed. The stress field distribution characteristics are obtained, and the stress field distribution characteristics of different areas directly above and on both sides of the floor roadway are obtained, which provides a theoretical basis for the location selection and support of the floor roadway.

scholarly journals Two-dimensional flow field distribution characteristics of flocking drainage pipes in tunnel

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 139-148
Author(s):  
Shiyang Liu ◽  
Xuefu Zhang ◽  
Feng Gao ◽  
Liangwen Wei ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Flow Field ◽  
Field Distribution ◽  
Rapid Development ◽  
Maximum Velocity ◽  
Distribution Characteristics ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Laboratory Test Results ◽  
Transverse Distance ◽  
Two Dimensional Flow

AbstractWith the rapid development of traffic infrastructure in China, the problem of crystal plugging of tunnel drainage pipes becomes increasingly salient. In order to build a mechanism that is resilient to the crystal plugging of flocking drainage pipes, the present study used the numerical simulation to analyze the two-dimensional flow field distribution characteristics of flocking drainage pipes under different flocking spacings. Then, the results were compared with the laboratory test results. According to the results, the maximum velocity distribution in the flow field of flocking drainage pipes is closely related to the transverse distance h of the fluff, while the longitudinal distance h of the fluff causes little effect; when the transverse distance h of the fluff is less than 6.25D (D refers to the diameter of the fluff), the velocity between the adjacent transverse fluffs will be increased by more than 10%. Moreover, the velocity of the upstream and downstream fluffs will be decreased by 90% compared with that of the inlet; the crystal distribution can be more obvious in the place with larger velocity while it is less at the lower flow rate. The results can provide theoretical support for building a mechanism to deal with and remove the crystallization of flocking drainage pipes.

Effects of the Shape of Workpiece on the Temperature and Stress Field Distribution during Laser Transformation Hardening

2012 ◽  
Vol 39 (8) ◽  
pp. 0803001
Author(s):  
张哲 Zhang Zhe ◽  
韩彬 Han Bin ◽  
王勇 Wang Yong ◽  
王楠楠 Wang Nannan
Keyword(s):  
Stress Field ◽  
Field Distribution ◽  
Laser Transformation Hardening

scholarly journals Failure Mechanism and Control Technology of Thick and Soft Coal Fully Mechanized Caving Roadway under Double Gobs in Close Coal Seams

2020 ◽  
Vol 2020 ◽  
pp. 1-23
Author(s):  
Shengrong Xie ◽  
Xiaoyu Wu ◽  
Dongdong Chen ◽  
Yaohui Sun ◽  
En Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Field Distribution ◽  
Control Technology ◽  
Coal Seams ◽  
Anchor Bolt ◽  
Anchor Cable ◽  
Coal Pillars ◽  
Seam Mining ◽  
And Control

The surrounding rock of the roadway under double gobs in the lower coal seams is partially damaged by the mining of the upper coal seam and the stress superimposition of the stepped coal pillars. What is worse, the upper layer of the roof is collapse gangue in double gobs, which makes the anchor cable unable to anchor the reliable bearing layer, so the anchoring performance is weakened. The actual drawing forces of the anchor bolt and anchor cable are only approximately 50 kN and 80 kN, respectively. The roadway develops cracks and large deformations with increasing difficulty in achieving safe ventilation. In view of the above problems, taking the close coal seam mining in the Zhengwen Coal Mine as the engineering background, a theoretical calculation is used to obtain the loading of the step coal pillars and the slip line field distribution of the floor depth. The numerical simulation monitors the stress superimposition of stepped coal pillars and the distribution of elastoplastic areas to effectively evaluate the layout of mining roadways. The numerical simulation also analyzes the effective prestress field distribution of the broken roof and grouting roof anchor cable. A laboratory test was used to monitor the strength of the grouting test block of the broken coal body. Then, we proposed that grouting anchor cable be used to strengthen the weak surface of the roof and block the roof cracks. From on-site measurement, the roadway was seen to be arranged in the lateral stress stabilization area of the stepped coal pillars, the combined support technology of the grouting anchor cable (bolt) + U type steel + a single prop was adopted, the roadway deformation was small, the gas influx was reduced, and the drawing force of the anchor bolt and the anchor cable was increased to approximately 160 kN and 350 kN, respectively. The overall design and control technology of the roadway can meet the site safety and efficient production requirements.

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