Shield tunneling construction method in overlapped tunnel in water-rich silt stratum

Abstract

The invention discloses the technical field of tunnel construction, in particular to a shield tunneling construction method in an overlapped tunnel in water-rich silt stratum. The shield tunneling construction method in the overlapped tunnel in water-rich silt stratum comprises the steps of a, setting up a support system; b, tunneling in a test section, and obtaining construction parameters; c, configuring a dual-slurry injection system, a cleaning system and a mixer; d, determining a matching ratio of a dual-slurry; e, formally conducting tunneling construction; f, conducting muck conditioning, and synchronously conducting dual-slurry injection construction; g, conducting solidification treatment on soil body outside a segment inside a hole. According to the shield tunneling construction method in the overlapped tunnel in the water-rich silt stratum, the support system is placed temporarily in a lower track, thus the problem that a down tunnel and the segment of the down tunnel are prone to damage is solved so as to accomplish protection for the down tunnel; by the arrangement of the dual-slurry injection system, a slurry after being mixed is injected to the back of the segment, thus the slurry fast solidifies and fast reaches needed strength, a water stopping effect is effectively formed, and thus occurrence of sedimentation of the soil body is avoided in the construction process.

Description

technical field [0001] The invention relates to the technical field of tunnel construction, in particular to a shield tunneling construction method for overlapping tunnels in water-rich powder soil strata. Background technique [0002] In recent years, my country's urban rail transit has developed rapidly. In the process of urban tunnel construction, shield machines are usually used for tunnel excavation. Due to the influence of urban environment and subway lines under construction in the planning of shield tunnels, new construction It is inevitable that the subway lines will intersect with the completed or operated tunnels. In the prior art, the construction parameters are usually obtained through trial excavation in the test section. During the trial excavation process, the mixed amount of dregs modifier is tested at the same time, and the process parameters are collected and sorted out. In the formal shield construction process, the construction is carried out according t...

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Problems solved by technology

[0006] The purpose of the present invention is: when carrying out shield excavation construction in the water-rich powder soil layer, when there is a built tunnel under the construction tunnel, the upper and lower tunnels overlap and the clear distance between the two tunnels is too small, there is an upward tunnel The problem of damage to the descending tunnel and its segments during excavation construction, and in this case, the amount of grout injected into the water-rich powder soil layer is small, cannot be solidified quickly, and cannot effectively stop water and support the weight of the soil. The shield tunneling construction method of overlapping tunnels in the ground layer. This method arranges temporary supports in the lower track and adopts a double-fluid grouting system at the same time to complete the protection of the descending tunnel. Mix and pour into the back of the segment synchronously, so that the grout in the uplink tunnel construction can quickly solidify and reach the required strength, effectively forming a water-stop effect, thereby avoiding the settlement of the soil during the construction process

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