scholarly journals Discussion On The Optimization of Circumferential Distance Of The System Bolt In A Highway Tunnel

2021 ◽  
Vol 272 ◽  
pp. 02013
Author(s):  
Kun Wang ◽  
Shun Yu ◽  
Yong Pan ◽  
Lushi Wang

The setting of circumferential distance of system anchor rod in highway tunnel is related to the safety of tunnel structure, and also affects the project cost. The “code for design of highway tunnels” issued in 2018 also adjusted the circumferential spacing arrangement of the system bolts of the tunnel. Based on a highway tunnel project, the circumferential spacing of system bolts in deep buried section of grade V surrounding rock is adjusted from 0.8m to 1.2m, and the numerical simulation and comparative analysis before and after the optimization of bolt spacing are carried out. The field monitoring and measurement data show that the surrounding rock deformation after adjustment has little effect, and the cavern is stable as a whole, which can guide the optimization implementation of subsequent sections.

2013 ◽  
Vol 438-439 ◽  
pp. 949-953
Author(s):  
Hao Bo Fan ◽  
Jin Xing Lai ◽  
Dan Dan Hou

This paper based on Chaoyang tunnel by bench method excavation, using the finite element numerical simulation method, simulates the surrounding rock displacement of soft rock tunnel and the stress characteristics of supporting structure to get the various stages of tunnel surrounding rock stress, strain and the internal force changes of tunnel supporting structure. After the analyses of the numerical simulation results and field monitoring measurement data, the safety and rationality of the method are determined. The research provides certain reference for highway tunnel design and construction.


2013 ◽  
Vol 368-370 ◽  
pp. 1812-1815 ◽  
Author(s):  
Yong Qin Zhang ◽  
Le Le Sun ◽  
Wei Zhong Zhang ◽  
Li Dan Cao

In order to solve the technical problem of gob-side entry retaining in inclined coal seam, combined with the practical mining conditions in a certain mine, this paper adopts the discrete element method, applies numerical simulation to analyze inclined coal seam gob-side entry retaining with three different supporting ways, and studies surrounding rock deformation characteristics of gob-side entry retaining. The research results show that the filling body upper boundary for right side can control the roadway surrounding rock deformation better compared with the boundary is used as the hypotenuse; Meanwhile, the pressure of surrounding rock of coal seam gob-side entry retaining is mainly from the impact of the immediate roof natural fall of the upper goaf tilt and the weight of caving coal gangue and coal seam of immediate roof above; According to the surrounding rock deformation characteristics of coal seam remain gateway along goaf, it is determined to use combined supporting method of concrete filling in roadway sides and anchor wire rope supporting inside the roadways, providing the design basis of gob-side entry retaining in coal seam for the similar geological conditions.


2021 ◽  
Vol 248 ◽  
pp. 03031
Author(s):  
Chen Zhengwen

In order to understand and grasp the law of roof pressure on the working face of deep inclined coal seams, the law of support resistance distribution, the law of leading support stress distribution and the law of surrounding rock deformation of the two roadways, the 94101 working face of Zhangshuanglou Coal Mine was taken as the engineering background. Through a combination of field measurement, numerical simulation, theoretical analysis, etc, this paper analyzes the laws of roof migration and rock pressure manifestation in deep inclined coal seams.


2012 ◽  
Vol 204-208 ◽  
pp. 1514-1517
Author(s):  
Zhi Jie Sun

The 3D finite element simulation are adopted to study the surrounding rock deformation regularity of main tunnel during the horizontal adit construction stage.The Zhongtiaoshan highway tunnel is taken as an example. The research results are shown as follows:Horizontal adit excavation destroys the original arching effect of the main tunnel, which leads to stress concentration at the intersection of primary supporting structure. The first excavation step plays an important play in the surrounding rock deformation of the intersection. The influence range of the main tunnel which due to the horizontal adit excavation is 1.2D.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Chaolin Liu ◽  
Guohua Zhang

In order to effectively solve a series of problems such as the difficulty of coal and rock interbed roadway support in Gaojiazhuang Coal Mine and get a scientific and reasonable optimization scheme of surrounding rock support, theoretical analysis, numerical simulation, ultrasonic detection, field-effect test, and other means are adopted to analyze the instability of coal and rock interbed roadway. The results show that the interbedded roadway has weak interbedded cementation, and its ore pressure is more intense due to the influence of its interbedded weak structural plane. Based on Mohr’s strength envelope principle, it is proposed that horizontal stress is the main factor that causes a wide range of shear displacement, penetration crack, and surrounding rock failure of the roof of this kind of roadway. Through the finite element numerical simulation analysis, the deformation and failure law, stress distribution characteristics, and failure area distribution characteristics of coal and rock interbedding roadway surrounding rock are theoretically revealed, and the control effect of different support schemes on roadway surrounding rock deformation is greatly different. Based on the ultrasonic detection technology, it is proved that the roadway side failure has strong zoning characteristics, and the failure range and stress distribution range of the surrounding rock of the belt roadway in the 2103 working face of Gaojiazhuang Coal Mine are detected. Finally, the coupling strengthening support scheme combining prestressed anchor cable and bolt is proposed. The engineering application and the observation of surrounding rock deformation show that the reinforced support technology can effectively enhance the stability of the surrounding rock of the interbed roadway in Gaojiazhuang Coal Mine, and it has a good reference for the surrounding rock conditions of this kind of roadway.


2012 ◽  
Vol 170-173 ◽  
pp. 1450-1454
Author(s):  
Xun Li ◽  
Chuan He ◽  
Guo Wen Xu

Taking Motianling tunnel in Chongqing as an engineering background, the monitoring and measurement scheme is proposed for the extra-long tunnel under complex condition, and the field data and the numerical simulation results is analyzed. The results indicates that, the selected cross-section reflect overall state of the Motianling tunnel, and the structure safety monitoring during operation is considered; by tunnel internal and external observation, it is found that the tunnel face in F22 fault zone may not stay stability, because the monitoring information receive feedback timely, and the supporting measures is proper, the surrounding rock stay stability when excavating; for the typical section, the surrounding rock contact pressure is greater than interlayer pressure, primary lining sustains most of the load ,and the secondary lining plays an assistant role as safety reservation; the maximum of anchor axial force and surrounding rock pressure occur at tunnel crown. By monitoring and numerical simulation, the dynamic excavation and design is realized, the Motianling tunnel is achieved safely and successfully at last.


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