A Series Solution for 2D Scattering of Cylindrical SH-Waves by Surrounding Loose Rock Zone of Underground Tunnel Lining

Jin, Lu; Sun, Hongyang; Wang, Shengnian; Zhou, Zhongyi

doi:10.3389/fphy.2021.772823

Cited by 2 publications

(1 citation statement)

References 34 publications

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“…The yielding anchor bolt support adopted in this article is an active support method based on the theory of the surrounding rock loosening circle, which allows the surrounding rock to undergo certain deformation and release a certain amount of dynamic pressure in the early stage of support, reducing the probability of anchor failure. At the same time, the yielding anchor bolt can enable the surrounding rock to have a certain bearing capacity [23][24][25][26] and is assisted by initial support methods such as an I25 steel arch and sprayed concrete, thus achieving the goal of effectively controlling the large deformation of weakly cemented surrounding rocks [27][28][29].…”

Section: Introductionmentioning

confidence: 99%

Analysis of Control Technology for Large Deformation of a Geological Bedding Bias Tunnel with Weakly Cemented Surrounding Rock

Ju,

Liu,

et al. 2023

Sustainability

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The Baishitou Tunnel of the Dali–Lincang railway project is a weakly cemented surrounding rock tunnel with geological bedding bias. The deformation of the surrounding rock on the side with the greatest stress is nearly 1 m, which seriously affects construction progress and significantly increases construction cost. In order to achieve the goal of safe, efficient, economic, and socially sustainable development in tunnel construction, it is necessary to study the large deformation of weakly cemented surrounding rock in the geological bedding bias tunnel. Engineering technicians first used field measurement methods to monitor the pressure and deformation of surrounding rock and studied the deformation law of surrounding rock pressure and deformation over time. Secondly, numerical simulation methods were used to study the stress distribution law, plastic failure depth, and initial support stress of tunnel-surrounding rock under different support schemes, and they independently designed a yielding anchor bolt with enhanced anchoring, which plays a key role in controlling the deformation of the surrounding rock. The main conclusions are as follows: (1) Through the analysis of the measured pressure data of the initial branch of the section and the displacement monitoring data of the measuring point, it is found that the deformation of the surrounding rock of the weakly cemented tunnel is large and fast. At the same time, the pressure and deformation of the surrounding rock of the tunnel are greatly affected by geological bedding bias. After the excavation of the inverted arch, the pressure and deformation of the surrounding rock at the right arch shoulder of the tunnel are the highest, reaching 0.832 MPa and 0.53 m, which are significantly greater than those on the left arch shoulder. (2) Using the numerical simulation software FLAC3D 5.0 and ANSYS 16.0, a three-dimensional numerical model of the roadway was established to simulate the stress distribution, plastic failure depth, and initial support stress of the tunnel’s surrounding rock under the influence of geological bedding bias. By comparing the support effects of different support schemes, it was concluded that under the support scheme of “I25 arch + yielding anchor bolt”, the surrounding rock failure depth was small, the stress concentration was weak, and the initial support deformation was controllable as a whole. (3) The self-designed yielding anchor bolt has good economic and applicable value, and it has received the expected support effect after field verification. (4) Various special support measures such as advanced grouting anchor rods, casing arches, or temporary cross supports are used to assist in controlling the large deformation of weakly cemented surrounding rock tunnels to a certain extent.

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