Multi-tunnel construction method based on soft interlayer

Abstract

The invention discloses a multi-tunnel construction method based on a soft interlayer. The method comprises the following steps of measuring the position of the soft interlayer, and uniformly distributing guide pipes on the soft interlayer, grouting the soft interlayer through the guide pipes to form a grouting area; uniformly distributing a plurality of tunnels to be constructed on the two sidesof the soft interlayer, measuring the rock and soil mass parameters of the tunnels;uniformly distributing blast holes in a core area, arranging blast holes and energy absorption holes in a buffer area, wherein the blast holes in the buffer area are surrounded by the energy absorption holes; continuously blasting the non-adjacent tunnels according to a preset sequence until all the tunnels are exploded, wherein when the displacement change amount of the surrounding rock and / or the change amount of the surface subsidence is larger than a preset threshold value, grouting is carried out on the soft interlayer through the guide pipes, the number of the blast holes is reduced and / or the amount of explosives in the blast holes is reduced, continuously blasting the non-adjacent tunnels according to a preset sequence, and enabling the displacement change amount of the surrounding rock and / or the surface settlement change amount is smaller than a preset threshold value.

Description

technical field [0001] The invention relates to the technical field of precise blasting and excavation of tunnels, in particular to a multi-tunnel construction method based on weak interlayers. Background technique [0002] Natural rock mass is not homogeneous, which contains a large number of joints and weak interlayers. Weak interlayer is one of the major engineering geological problems often encountered in geotechnical engineering, and it is also an object that needs to be studied emphatically in engineering. Weak interlayer generally refers to a thin layer with fine particles, sheet-like structure, easy to soften or muddy when exposed to water, low mechanical strength, and relatively weaker than the upper and lower rock layers. According to its origin, it can be divided into three types: structural, primary, and secondary. Type, where the muddy part is called the muddy interlayer. Weak interlayers are widely distributed, involving almost all regions and various rock fo...

AI Technical Summary

Problems solved by technology

There are weak interlayers in the rock mass, and the weak interlayers make the constitutive relationship of the material more complicated. Even if the engineering rock mass is regarded as an elastic medium to establish a wave equation about the propagation of stress waves, the complex boundary conditions and initial conditions also make the equation hard to get exact solution

Therefore, some scholars have used numerical simulation to study the influence of the properties of weak interlayers on the intensity of stress waves, but there is still a lack of analysis on the mechanism of energy dissipation, and a lack of in-depth research on the explosion source model in numerical simulation.

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