Research purposes: Water is a common geological environment of tunnel structure. It is necessary to consider the influence of water on the damping performance of new primary supporting materials. In this paper, the influence of water on the mechanical properties of steel fiber foamed concrete which is suitable for tunnel initial support is analyzed. Finally, a three-dimensional composite lining tunnel structure model is built through numerical simulation to explore the damping performance of the new initial support in water-free and water-rich strata.
Research conclusions: (1) The dynamic modulus of wet steel fiber foamed concrete increases with the increase of water content. The quasi-static uniaxial compressive strength and tensile strength decrease with the increase of water content. (2) The initial support of steel fiber foamed concrete has obvious shock absorption effect, the shock absorption rate is up to 41.43%; The higher the level of surrounding rock, the more significant the damping effect; When the intensity of seismic fortification increases, the improvement of the damping effect is not obvious. (3) In water-free strata, the effect of initial support with different thickness has a marginal effect, while in water-rich strata, the marginal effect disappears. The recommended values of initial support thickness of steel fiber foamed concrete under different working conditions are given for reference in practical construction.
Key words
steel fiber foamed concrete /
initial support /
water-rich /
dynamic modulus /
shock absorption
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