Construction method of super-deep shield shaft in water-rich weak stratum

Abstract

The invention discloses a construction method of a shield shaft. The method comprises the following steps that 1, an underground continuous wall enclosure structure of the shaft is constructed; 2, thestratum at the end of the shield shaft is reinforced; 3, the upper 20-m portion of the shaft is divided into four layers, and excavation and erection of a steel bracing support system are conducted layer by layer; 4, the lower portion of the shaft is divided into five layers, and the fifth layer to the ninth layer of the shaft are excavated separately; 5, the pit bottom of the shaft is treated, pile head concrete of an uplift pile is broken and removed at first, then the bottom is manually cleaned, base cushioning and water proofing construction is carried out, finally, bottom plate steel ribs are tied, and concrete is poured; 6, a shaft support is disassembled, and side walls and columns are constructed. The construction method of the shield shaft has the advantages that through construction methods of vertical layering, construction from top to bottom and support at first and afterwards excavation, the construction efficiency of the shield shaft is effectively improved; by setting the steps of reinforcing a shield receiving end, the shield receiving end is effectively protected against damage in the construction process of the shaft.

Description

technical field [0001] The invention relates to the technical field of shield shaft excavation and lining construction, in particular to a construction method for an ultra-deep shield shaft in a water-rich and soft stratum. Background technique [0002] The shield shaft is a well-shaped structure in which the shield device is lowered into the shield device for starting or the shield machine is lifted out of the shield machine during the shield tunneling method construction process. At present, with the popularization of the application of the shield machine, more and more applications are made to the shield shaft. [0003] For example, the patent document of Chinese invention patent application number 201310480442.6 discloses a construction method of a shield shaft assembly type concrete filled steel tube inner support system, the steps are as follows: [0004] The first step is the factory manufacturing of rectangular concrete-filled steel tube components: in the factory, ...

AI Technical Summary

Problems solved by technology

[0014] 1. Using custom-made rectangular concrete-filled steel tube components and fittings for assembly operations will produce rectangular concrete-filled steel tube components and fittings that cannot be assembled on site due to on-site construction errors, reducing construction efficiency;

[0015] 2. Use micro-expansion concrete to fill the space between the concrete-filled steel pipe purlin and the inner wall of the shield shaft, so that the combination between the steel pipe concrete purlin and the inner wall of the shield shaft is not strong enough

[0016] 3. This technology is only suitable for relatively shallow shield shafts with good geological conditions (such as shafts with a depth of no more than 30m), but for ultra-deep shafts with a depth of more than 40m in soft strata rich in water and with confined water , this technology has major security problems and is not applicable

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