Determination Method of Critical Water Pressure and Critical Thickness for Three-dimensional Water Inrush Damage of Tunnel Vault

Abstract

The invention discloses a method for determining the tunnel arch crown three-dimensional water inrush damage critical inner water pressure and critical thickness. The method comprises the steps that on the basis that when tunnel arch crown critical water inrush damage occurs, the sum of water pressure work power and water-resisting layer gravity work power is equal to internal energy dissipation power at the three-dimensional fracture surface, water pressure external force power, water-resisting layer external force power and internal energy dissipation power are calculated separately, and functional containing the water pressure external force power, the water-resisting layer external force power and the internal energy dissipation power is constructed; according to the condition of seeking an extreme value through a variational method and by combining displacement, the stress boundary condition and the law of conservation of energy, the critical inner water pressure in the arch crown water inrush damage process is determined when the water-resisting layer is known; or the water-resisting layer critical thickness is determined when the water-bearing layer water pressure is known; meanwhile, according to an obtained fracture surface function, a three-dimensional fracture surface outline drawing in the water inrush process can be drawn. Accordingly, whether or not a tunnel arch crown is subjected to water inrush and whether or not the water-resisting layer thickness meets the requirement can be judged, and the basis is provided for drainage for pressure reduction.

Description

technical field [0001] The invention belongs to the field of tunnel water inrush damage, and in particular relates to a method for determining the critical water pressure and critical thickness of tunnel vault three-dimensional water inrush damage. Background technique [0002] With the rapid advancement of my country's western development strategy, infrastructure construction such as transportation and energy in the western region has been greatly expanded, and more and more long tunnels have been constructed. During the construction of long tunnels, geological disasters such as water and mud inrush, rockburst, and gas are often encountered, among which water and mud inrush are particularly serious. Water and mud inrush disasters range from destroying machinery and tools, delaying the construction period, to causing casualties and heavy property losses. Therefore, it is of great engineering significance and scientific value to carry out research on tunnel water inrush. At...

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Problems solved by technology

At present, numerical simulation or empirical formulas are mostly used to determine the critical thickness of tunnel water inrush, or thin plate theory and beam theory are used for analysis, but there are few studies on the critical water pressure of water inrush; at the same time, most of the research on water inrush is based on karst tunnels. water inrush at the face of tunnels, and there are few studies on water inrush at tunnel vaults

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