Study on Safe Distance between Cross-Cut and Lower Belt Tunnel

2011 ◽  
Vol 121-126 ◽  
pp. 3525-3529
Author(s):  
Xing Lin Wen ◽  
Chuan Lei Li ◽  
Fei Yu ◽  
Lin Hai Gao

In order to solve the question of safe distance between cross-cut and lower lane bolt tunnel and support, aim at geological and mining conditions of north mining area in sanjiaohe coal mine, and analysis mechanism of surrounding rock deformation, analysis the upper roadway surrounding rock stress, displacement and distruction of plastic by FLAC3D determine the minimum distance between the two tunnel and design support scheme on the basis of on-site roadway conditions. Result of this study can provide a reference not only in this mine but also for another similar situtions roadway.

2013 ◽  
Vol 353-356 ◽  
pp. 828-832
Author(s):  
Guo Feng Wang ◽  
Wen Zhao ◽  
Yong Ping Guan ◽  
Lei Liang

The non-pillar sublevel caving method is used in Iron Mine in Banshi. In the mining area, there are many folds and faults, the inclination of ore body changes greatly, and ore and rock are fragmentized. The tunnel often collapsed and the surrounding rock deformation was getting large during the construction stage. Using the data of tunnel surrounding rock deformation, we adopt the neural network method to set up the mapping relation between the tunnel surrounding rock deformation and the project factors, including tunnel deepness, tunnel dimension, measuring time and surrounding rock quality. The analyzing results show that the maximum error between the forecast and the testing data is 13%, which indicates that this method is useful and feasible to the mining engineering. Key words: rock pressure; measure, deformation of the tunnel surrounding rock; neural network; data normalization; mapping


2014 ◽  
Vol 580-583 ◽  
pp. 1364-1368 ◽  
Author(s):  
Hua Jun Xue ◽  
Jun Long Xue ◽  
Ming Lun Yin ◽  
Jie Kong ◽  
Zong Ming Gao

Since the excavation of roadway in Shuguang mine No.2 mining area, shotcrete layer has fallen off and the surrounding rock deformation was serious. For studying big deformation of roadway in Shuguang mine No.2 mining area, the paper analyzed fractured surrounding rock physical and mechanical characteristics of No.2 mining area. The results show that the uniaxial compressive strength, uniaxial tensile strength, cohesion, internal friction angle of fractured surrounding rock were very low. And the whole physical and mechanical characteristics were poor. It is the basic reason of big deformation of roadway surrounding rock physical and the important basis of late supporting of roadway.


2012 ◽  
Vol 170-173 ◽  
pp. 1735-1739
Author(s):  
Ying Na Dong ◽  
Qiang Huang

The surrounding rock stress field monitor has been done in excavation by vibrating wire transducer. The field monitoring data are compared with numerical simulation results. The result shows: Vibrating wire transducer can record the stress variation of surrounding rock and support. Surrounding rock stress changes violently at every excavation step, such as lower bench excavation, the stress variation is mainly controlled by the spatial effect. When the distance from excavation face to the monitoring section is more than a tunnel diameter, the rock stress variation is mainly affected by time and it is relatively smooth and continuous.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hongjun Guo ◽  
Ming Ji ◽  
Dapeng Liu ◽  
Mengxi Liu ◽  
Gaofeng Li ◽  
...  

In order to further explore the deformation and failure essence of the deep coal body, based on the characteristics of surrounding rock stress adjustment before and after solid coal roadway excavation, an experiment of unloading confining pressure and loading axial pressure of the coal body was designed and conducted in this study. Based on test results, the failure mechanics and energy characteristics of the coal body were analyzed through experiments. Rapid unloading is considered a key factor contributing to lateral deformation and expansion failure, which exacerbates the deterioration of coal body and reduces the deformation energy storage capacity of coal. On the other hand, the larger loading rate tends to shorten the accumulation time of microcracks and cause damage to the coal body, resulting in strengthening the coal body and improving energy storage. Under the circumstance that the coal body is destroyed, the conversion rates of the internal deformation energy and dissipated energy are more significantly affected by unloading rate. The increasing unloading rate and rapid decreases in the conversion rate of deformation energy make the coal body more vulnerable to damage. Under the same stress conditions, the excavation unloading is more likely to deform, destroy, or even throw the coal than the experiment unloading. In order to reduce or avoid the occurrence of deep roadway excavation accidents, the understanding of the excavation unloading including possible influencing factors and the monitoring of the surrounding rock stress and energy during the excavation disturbance should be strengthened. It can be used as the basis for studying the mechanism of deformation and failure of coal and rock and dynamic disasters in deep mines, as well as the prediction, early warning, prevention, and control of related dynamic disasters.


2018 ◽  
Vol 175 ◽  
pp. 04016
Author(s):  
NIU Yan ◽  
Ji Yafei ◽  
Wang Zhao

Tunnel excavation will lead to the immediate surrounding rock unloading caused by the surrounding rock stress release, the stability of the surrounding rock have a certain impact. In this paper, finite element software ANSYS and finite difference software FLAC3D are used to simulate the excavation and lining process of circular tunnel. The influence of excavation on the rock stability around circular tunnel is analyzed, and the effect of applying lining on the stability of surrounding rock is analyzed. Evaluation criteria selection hole displacement, stress and plastic area of three factors.


Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 458 ◽  
Author(s):  
Daoyong Zhu ◽  
Jiong Wang ◽  
Weili Gong ◽  
Zheng Sun

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.


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