Publications
Sort:
Open Access Issue
Study on the Effect of Structural Joints on Tunnel Rockburst Mode
Chinese Journal of Underground Space and Engineering 2023, 19(5): 1584-1592
Published: 01 October 2023
Abstract PDF (3 MB) Collect
Downloads:0

Under the action of structural stress, the internal joints of rock mass are generally developed, and the joints have an important effect on the occurrence of rockburst in deep tunnels. In order to study the relationship between the joints distribution and rockburst failure, based on the distribution law of rockbursts and structural joints in Caoguoshan tunnel, the distribution characteristics and evolution process of fractures are analyzed through acoustic emission data, and Rock Failure Process Analysis Software (RFPA) is used for research. The results show that the joints parallel to the tunnel axial direction are more likely to cause rockburst than those perpendicular to the tunnel axial direction. The joints hidden inside the surrounding rock and close to the excavation contour are more likely to cause rockbursts, while the change of their dip angle has little effect on the rockbursts. The existence of joint surfaces in the surrounding rock makes the stress rapidly concentrate in the thin rock mass between the joint surface and the excavation boundary, and the maximum principal stress will transition from the surface of the surrounding rock to the interior of the surrounding rock, and the stress boundary is in the shape of a concave arc, similar to the "V" or "pan" type blasting crater after rockburst. The research results have certain reference value for the planning and route selection, rockburst prediction and prevention of actual projects.

Open Access Issue
Study on the Effect of Rock Bolting Parameters on Rock Explosion Prevention
Chinese Journal of Underground Space and Engineering 2023, 19(1): 326-333
Published: 01 February 2023
Abstract PDF (2.6 MB) Collect
Downloads:0

Rockburst is a dynamic disaster that seriously threatens the safety of underground constructions. There are many rockburst indexes, but none of them consider the supporting effect. This paper is based on both elastic strain energy theory and anchorage effect and bolt absorption theory. Moreover, the criterion for identifying the risk of rockburst under rock bolting is proposed. Taking the Caoguoshan tunnel as an example, the effect of rockburst prevention under different rock bolting parameters was studied. Four parameters were focused on, including bolt spacing, bolt length, bolt diameter, and bolt type. Experimental analyses were carried out under different rockburst grades, and the results show that the order of parameters’ impact on the rockburst criterion is bolt type>bolt spacing>bolt length>bolt diameter. In addition, the optimal parameter selection for rock bolting under different rockburst grades is obtained, which provides a reference for the design of support measures for similar highland stress tunnels.

Total 2