Cross section structure for rectangular shield tunnel

Abstract

The invention discloses a cross section structure for a rectangular shield tunnel. The cross section structure is formed by sequentially connecting a top inverted arch, a first angle part, a first side wall, a second angle part, a bottom inverted arch, a third angle part, a second side wall and a fourth angle part in series; the fourth angle part is connected with the top inverted arch; all parts define a closed ring; the inner contour and the outer contour of the closed ring are smooth and continuous; the ring width of the closed ring is continuously changed; the ring width positioned in a large-stress area of the tunnel is greater than the ring width positioned in a small-stress area of the tunnel. The applicant provides an idea of variable wall thickness of the rectangular shield tunnel and develops the cross section structure for the rectangular shield tunnel; the ring width positioned in the large-stress area of the tunnel is greater than the ring width positioned in the small-stress area of the tunnel, so that mechanics characteristics of the tunnel are more accurately matched on the premises of not increasing self weight, not wasting the cross section and not influencing an inner use space.

Description

technical field [0001] The invention relates to the technical field of tunnel section structure design, in particular to a section structure of a rectangular shield tunnel. Background technique [0002] In the soft soil area, the traditional shield tunnel is constructed by a single-round shield machine, and its cross-section is circular. With the continuous improvement of people's requirements for underground roads and rail transit, the scale of shield tunnels continues to increase, but almost all of them adopt the form of circular cross-sections. Although the technology of shield tunnel with circular section is mature, there are still the following unfavorable factors: (1) the effective use area of ​​circular section is small, and the structural section cannot be fully utilized; (2) the amount of earthwork produced by shield tunneling during excavation (3) The burial depth of the shield tunnel is about 1.0D (D is the diameter of the shield), which increases the excavation ...

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Problems solved by technology

[0004] The applicant found in engineering practice that although the rectangular shield tunnel can make better use of the underground space and is suitable for shallow buried and underground excavation in soft soil areas, the stress conditions of the rectangular tunnel and the circular tunnel are completely different, and the cross-section is subject to bending. Mainly, the tunnel section structure in the prior art does not fully match its actual stress characteristics, resulting in increased self-weight and waste of section, which needs further improvement

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