A method for constructing tunnels through rockburst areas

Abstract

The invention relates to a method for constructing a tunnel passing through a rockburst section, comprising the following steps: step 1, applying a bolt on the tunnel face to control the rockburst at the tunnel face; Grooving, the length of the longitudinal slotting of the tunnel is always ahead of the tunnel face, and part of the surrounding rock of the core soil is reserved; step 3, after the slag is excavated, the profiled steel arch frame and steel mesh are constructed, energy-dissipating anchors are laid, and large damping flexibility is injected Filling with materials, spraying steel fiber concrete on the surface; Step 4, while applying initial support, apply pull anchors on the core soil along the direction of the tunnel cross section, and vertically drive glass fiber anchors into the core soil; Step 5, according to the predetermined The core soil is excavated by step-by-step blasting, the blast hole is charged with the axial hollow bolt hole, and the core soil is cut horizontally. The invention can control the occurrence tendency of rockburst to a certain extent, and guarantee the safety of the tunnel construction process.

Description

technical field [0001] The invention relates to the technical field of railway tunnel construction, in particular to a tunnel construction method for crossing a rockburst section. Background technique [0002] With the rapid development of the national economy, the development of underground resources and underground infrastructure are developing at an unprecedented speed. With the increase of buried depth or the influence of tectonic stress, deep or ultra-deep tunnels will pass through complex formations. areas of high geostress. Rockburst is a common geological disaster in high ground stress areas. High elastic strain energy exists in the deep rock mass in the high geostress area, and energy accumulation will occur near the excavation surface under the influence of far-field stress during the excavation process. When the accumulated strain energy exceeds the energy storage limit of the rock mass , the excess energy is released suddenly, and causes part of the rock mass n...

AI Technical Summary

Problems solved by technology

Although this method can release the tunnel stress in advance, it also changes the mechanical properties of the surrounding rock in the rockburst section, resulting in the indeterminate release of the surrounding rock stress, which aggravates the occurrence tendency and uncertainty of the rockburst; the Chinese invention patent CN107893673A discloses an anti-rockburst and large-deformation wing-type extrusion energy-absorbing bolts, including: the bolt body and the tray and nuts arranged at its tail, which can improve the effect of absorbing pressure and controlling disasters such as rockbursts or large deformations in deep underground engineering, but the The structure of the invention is too simple, and the absorbed energy is limited when a rockburst occurs, so it cannot really dissipate the rockburst energy and effectively control the rockburst; Chinese invention patent CN106368721A discloses a tunnel rockburst prevention support method and tunnel rockburst prevention The support system includes surrounding rock, shotcrete layer and multiple prestressed energy-releasing bolts. The shotcrete layer is provided with multiple grooves arranged at intervals, which can prevent or reduce the occurrence of rockburst to a certain extent. trend, but this method will inevitably aggravate the stress concentration of the initial support sprayed concrete, and increase the possibility of rockburst on the other hand.

Furthermore, the above inventions all focus on weakening and controlling the occurrence of rockbursts, and cannot protect construction personnel and equipment when rockbursts occur, and reduce the impact of rockbursts.

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