Numerical Simulation on Supporting of Deep Surrounding Rock with Zonal Disintegration Tendency

2013 ◽  
Vol 671-674 ◽  
pp. 230-234
Author(s):  
Yu Jun Zuo ◽  
De Kang Zhu ◽  
Wan Cheng Zhu

In order to study the supporting of deep surrounding rock with zonal disintegration tendency, the zonal disintegration phenomenon of deep surrounding rock under three supporting forms is analyzed by the ABAQUS finite element software in this paper, and three supporting forms are un-supporting, bolting and grouting, and combined “Bolting and grouting plus Anchor rope” supporting. The results show that the different effects to zonal disintegration under different supporting forms will occur. Supporting can help to restrain the zonal disintegration of the reinforcement part advantageously, and also lower rupture degree of zonal disintegration and reduce the size of rupture zone. Meanwhile, the stability of surrounding rock is improved. But zonal disintegration may occur outside reinforcement part under greater ground stress. The results are great importance to a better understanding of the deep roadway supporting.

2011 ◽  
Vol 255-260 ◽  
pp. 1926-1929
Author(s):  
Da Kun Shi ◽  
Yang Song Zhang

Based on geologic condition of one tunnel surrounding rock mass, systematic numerical tests had been carried out to study the stability of surrounding rock mass with different distributions of weak intercalated rock by the FEM software ABAQUS and strength reduction finite element method. Some quantificational results about the stability of surrounding rock mass were summarized. And the safety factor and latent slip surface were worked out. The stability of surrounding rock mass was judged by strength reduction finite element method. According to the analysis above, it’s known that the discrepancy of two rules is small; the safety factor is the lowest when weak intercalated rock in vault, and when at bottom, it’s higher than that of in vault. The conclusion can be used to guide the procedure of construction and ensure the safety.


2012 ◽  
Vol 204-208 ◽  
pp. 1527-1531
Author(s):  
Jian Guo Zhang

In view of the double-track tunnel on passenger dedicated line with speed 250km/h, finite element programming has been employed to simulate dynamic construction process under shallow-buried and bias conditions with grade IV, including stony and soil, and grade V surrounding rock. Different construction methods under various operation conditions have been compared. Based on stability of surrounding rock and safety of primary and temporary lining, proper construction method under various operation conditions has been presented.


2013 ◽  
Vol 353-356 ◽  
pp. 1507-1510
Author(s):  
Bo Huang ◽  
Rui Jun Liu

The optimum shape of the tunnel is usually decided by many factors. Not only should it ensure the stability of surrounding rock and the advantageous of masonry's stress, but also it need to meet the using requirements of the cavern, the convenience of the construction, the least excavated volume and the best economic results. Seeking the optimal shapes of the carven which is under the specific condition has always been paid great attention by engineers. With the help of ADINA finite element analysis software, this paper imitates related data in elastic theory about the excavation of tunnels with the typical planes of fracture which are under the same geology condition. After that, it contrasts the actual computing results with the theoretical analysis, and then studies planes of fracture's optimal excavated shapes of the tunnels.


2015 ◽  
Vol 9 (1) ◽  
pp. 450-456 ◽  
Author(s):  
Peng Wen-qing ◽  
Wang Xin-min ◽  
Wang Wei-jun

This paper is based on the large section inclined shaft crossing goaf of Pingdingshan No.6 Mine as engineering background, and aimed at solving the difficult supporting problem of fractured surrounding rock. After establishing and calculating the mechanical models of U-steel and inverted arch, the support’s vertical reaction force (N1) and horizontal counterforce (X1) are determined as 180.96 KN and 48.12 KN, while the maximum bending stress (σmax) and ultimate bearing capacity of the inverted arch are obtained as 375.59 Mpa and 0.27 Mpa. It shows that the deformation of surrounding rock is well controlled by the supporting structure. The numerical simulation model is built by using the software FLAC3D to analyze the stability of surrounding rock after supporting. The results suggest that the deformation of roof, floor and sides is reduced by 17%, 23% and 71% respectively after supporting with U-steel in the inclined shaft, and the accuracy of results has been verified by a field experiment. Therefore, the “U-steel+ pouring concrete + inverted arch + backwall grouting” technology can effectively control the damage of surrounding rock and improve the stability of surrounding rock.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Xuguang Chen ◽  
Yuan Wang ◽  
Yu Mei ◽  
Xin Zhang

Zonal disintegration have been discovered in many underground tunnels with the increasing of embedded depth. The formation mechanism of such phenomenon is difficult to explain under the framework of traditional rock mechanics, and the fractured shape and forming conditions are unclear. The numerical simulation was carried out to research the generating condition and forming process of zonal disintegration. Via comparing the results with the geomechanical model test, the zonal disintegration phenomenon was confirmed and its mechanism is revealed. It is found to be the result of circular fracture which develops within surrounding rock mass under the high geostress. The fractured shape of zonal disintegration was determined, and the radii of the fractured zones were found to fulfill the relationship of geometric progression. The numerical results were in accordance with the model test findings. The mechanism of the zonal disintegration was revealed by theoretical analysis based on fracture mechanics. The fractured zones are reportedly circular and concentric to the cavern. Each fracture zone ruptured at the elastic-plastic boundary of the surrounding rocks and then coalesced into the circular form. The geometric progression ratio was found to be related to the mechanical parameters and the ground stress of the surrounding rocks.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Qi Li ◽  
Shuang You ◽  
HongGuang Ji ◽  
Huici Xu ◽  
Huan Wang

To analyze heat effect in deep metal mines, it is crucial to understand the temperature field distribution around the mine tunnel. In this paper, a numerical model of the random mineral composition of the rock body is established based on finite element software to analyze the influence of the internal composition of the surrounding rock on the temperature field, and a numerical simulation model based on COMSOL finite element software is established based on the two heat exchange modes of heat conduction and heat convection in the surrounding rock. The results show that the numerical simulation results of a typical numerical simulation model using a single material are lower than the real situation; increasing the tunnel length does not increase the heat exchange efficiency between the rock wall and the air; increasing the wind velocity has a limited impact on the temperature field; the wind temperature more directly affects the mining surface; and the effect of wet air on the temperature field of the surrounding rock has a more substantial variation.


Author(s):  
Sheng Yu-ming ◽  
Li Chao ◽  
Xia Ming-yao ◽  
Zou Jin-feng

Abstract In this study, elastoplastic model for the surrounding rock of axisymmetric circular tunnel is investigated under three-dimensional (3D) principal stress states. Novel numerical solutions for strain-softening surrounding rock were first proposed based on the modified 3D Hoek–Brown criterion and the associated flow rule. Under a 3D axisymmetric coordinate system, the distributions for stresses and displacement can be effectively determined on the basis of the redeveloped stress increment approach. The modified 3D Hoek–Brown strength criterion is also embedded into finite element software to characterize the yielding state of surrounding rock based on the modified yield surface and stress renewal algorithm. The Euler implicit constitutive integral algorithm and the consistent tangent stiffness matrix are reconstructed in terms of the 3D Hoek–Brown strength criterion. Therefore, the numerical solutions and finite element method (FEM) models for the deep buried tunnel under 3D principal stress condition are presented, so that the stability analysis of surrounding rock can be conducted in a direct and convenient way. The reliability of the proposed solutions was verified by comparison of the principal stresses obtained by the developed numerical approach and FEM model. From a practical point of view, the proposed approach can also be applied for the determination of ground response curve of the tunnel, which shows a satisfying accuracy compared with the measuring data.


2013 ◽  
Vol 405-408 ◽  
pp. 402-405 ◽  
Author(s):  
Yun Jie Zhang ◽  
Tao Xu ◽  
Qiang Xu ◽  
Lin Bu

Based on the fluid-solid coupling theory, we study the stability of surrounding rock mass around underground oil storage in Huangdao, Shandong province, analyze the stress of the surrounding rock mass around three chambers and the displacement change of several key monitoring points after excavation and evaluate the stability of surrounding rock mass using COMSOL Multiphysics software. Research results show that the stress at both sides of the straight wall of cavern increases, especially obvious stress concentration forms at the corners of the cavern, and the surrounding rock mass moves towards the cavern after excavation. The stress and displacement of the surrounding rock mass will increase accordingly after setting the water curtains, but the change does not have a substantive impact on the stability of surrounding rock mass.


2012 ◽  
Vol 544 ◽  
pp. 194-199
Author(s):  
Di Zhang ◽  
Shui Ping Sheng ◽  
Zeng Liang Gao

Two important parameters of torispherical head that are (interior radius of spherical crown area) and r (interior radius of transition corner) have been optimized by the module of the large general-purpose finite-element software ANSYS, targeting the strength and stability of the head. This paper provides an optimized torispherical head, which improves the stability of the edge of the head with acceptable strength of the head. The procedure is generally applicable as a design tool for optimal design.


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