Protective device and protective method for ditch pass-through of shield tunneling machine in ultra-shallow earth covering region

Abstract

The invention belongs to the technical field of civil engineering construction, and relates to a protective device for ditch pass-through of a shielding machine in an ultra-shallow earth covering region. The protective device comprises a cover plate, pressing mechanisms and a power mechanism, wherein the cover plate covers a to-be-passed-through ditch and base bodies at the two sides of the to-be-passed-through ditch; the pressing mechanisms are symmetrically arranged at the two ends of the cover plate; the power mechanism is connected to the pressing mechanisms, and drives the pressing mechanisms to downwards press the cover plate; and each pressing mechanism comprises a pressing rod, a ground anchor rod and a tripod, one end of the pressing rod is hinged with the tripod, the other end ofthe pressing rod is hinged with the power mechanism, the ground anchor rod is hinged and fixed on the pressing rod close to one end of the tripod, the tripod is arranged on the cover plate, and the tripod at the other end of the pressing rod downwards presses the cover plate while the power mechanism drives the other end of the pressing rod to move upwards. The protective device can effectively reduce upward destructive power generated while the shielding machine in tunnel shield construction passes through the ditch, keeps the original state of the ditch, and effectively avoids unsafe riskswhile the shielding machine constructs and operates.

Description

technical field [0001] The invention belongs to the technical field of civil engineering construction, and relates to a protection device and a method for a shield machine to cross a ditch, in particular to a protection device and a protection method for a shield machine to cross a ditch in an ultra-shallow soil-covered area. Background technique [0002] The shield tunnel construction method refers to the use of a shield machine to control the excavation surface and surrounding rock from collapse and instability accidents, on the one hand to carry out tunnel excavation and slag discharge, and to complete the assembly of segments in the machine to form lining and implement A method of constructing a tunnel without disturbing the surrounding rock by grouting behind the wall. [0003] When the shield machine is constructed in an area with a shallow covering soil section length of 80 meters and a covering soil thickness of 2.45 meters to 6 meters, the soil condition in the cons...

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Problems solved by technology

[0003] When the shield machine is constructed in an area with a shallow covering soil section length of 80 meters and a covering soil thickness of 2.45 meters to 6 meters, the soil condition in the construction area is good and there is no groundwater; however, the danger of construction lies in the thickness of the covering soil at the starting end of the shield section It is only 2.45 meters, which is far lower than the requirement of overburden thickness of more than 1 times the diameter of the shield (6.24 meters) required by the code; when the initial crossing of the shallow overburden section, the rotation of the shield machine generates an upward centrifugal force on the ground during the shield excavation process, The disturbance to the vault soil is large, especially in the ultra-shallow soil area. Due to the shallow soil layer, the shield machine generates an upward centrifugal force, and the pressure balance of the soil bin in front of the cutter head is not easy to establish, which makes the clay layer prone to cracks, causing surface cracks. Therefore, the atmospheric precipitation and ground flushing water in the ditch in the construction area flow into the position of the cutter head from the position where the crack is generated, and enter the shield machine from the opening of the cutter head; under the normal propulsion of the shield machine, it may cause the spout of the screw machine. The instability of the sub-surface causes risks such as ground collapse, which seriously affects the construction process and poses safety hazards

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