Improvement ability and parameters determination method of shield tunneling sandy muck soil

Abstract

The invention discloses a method for shield sandy muck improving capacity enhancement and parameter determining. Sandy soil consistent with a stratum where a shield penetrates through serves as a mucktest material, a foaming agent and water serve as a basic improving material, according to the muck collapsing degree value and the apparent state, the proper improving area is determined, accordingto whether the initial water containing amount of the sandy soil of the stratum where the shield is located is in the range of the water containing amount of the proper improving area or not, whetherwater needs to be injected or not is clear, whether bentonite or high-molecular polymer needs to be injected to enhance the capacity that the muck can be improved by the foaming agent and water, according to the proper improving area, the foam injection ratio is determined, the muck in the proper improving state is subjected to a penetration test, and whether the impervious performance of the muckmeets the construction need or not under the high water pressure condition at the shield site is detected. The clear muck improving thinking is provided, the direction is clear, the technology is reliable, and the method can be directly used for shield tunnel site construction.

Description

technical field [0001] The invention belongs to the technical field of construction of earth pressure balance shield tunnels in sandy strata, and in particular relates to a method for improving the improvement ability of shield tunnels in sandy dregs and determining parameters. Background technique [0002] The shield tunneling method has the advantages of high safety, fast excavation speed, and little impact on the surrounding environment, and is widely used in urban tunnels. The earth pressure balance shield is mainly suitable for strata where the mass of particles with a particle size of less than 0.06mm accounts for more than 30% of the total amount of muck, otherwise the mud-water balance shield is used. However, the construction of mud-water balance shield requires a large mud-water treatment plant, which occupies a large area, and the mud-water treatment is often inefficient, which often becomes a key factor restricting the progress of tunnel construction. Therefore,...

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Problems solved by technology

Even if the slump test is carried out to determine the improvement parameters, there is still a large blindness in parameter adjustment, or the improvement ability of bentonite or high molecular polymer is overly expanded, while the basic improvement performance of foaming agent and water is ignored, resulting in the improvement of muck. cost increase

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