Shield optimization design method for loosening and stripping sandy gravel stratum based on wedge coulter

Abstract

The invention discloses a shield optimization design method for loosening and stripping a sandy gravel stratum based on a wedge coulter. The method comprises the following steps of determining a shield wedge coulter form for loosening and stripping the sandy cobble stratum, and adopting a shell type wedge coulter; calculating the limit loads borne by the wedge coulter at different positions when the stratum is loosened and stripped, and determining the arrangement mode of the alloy blocks; determining the heights of the alloy blocks according to the stratum abrasiveness and interval characteristics; according to the limit loads borne by the wedge coulter, calculating the cutting force and the jacking force needed by the wedge coulter, and preferably selecting a cutter appearance characteristic parameter design scheme; performing targeted optimization design on the wedge coulter; and calculating the power required by the wedge coulter to loosen and strip the sandy gravel stratum, and configuring a power driving system of a shield tunneling machine according to the calculated required power. According to the method for loosening and stripping the small and medium particle size gravel-cobble stratums through the shield wedge coulter, the blank of stress research on the wedge coulter is filled up, and a theoretical basis is provided for the shield model selection and the shield power system design.

Description

technical field [0001] The invention relates to the technical field of shield tunneling, in particular to the optimal design of a shield tunneling system, in particular to a shield tunnel optimization design method based on wedge coulters loosening and exfoliating sand and pebble formations. Background technique [0002] In the construction process of urban subways, shield tunneling is widely used because of its advantages such as fast excavation speed, high safety, and small impact on ground traffic. Sand and pebble formations are widely distributed in Beijing, Shenyang, Lanzhou, Chengdu and other regions. When shield tunneling is carried out in sand and pebble formations, the tool wear is very serious. The life of the tool directly determines the construction period and project cost. [0003] The sandy pebble formation is a highly abrasive formation that is occluded and cemented together by discrete pebbles of different particle sizes. The undisturbed soil has high streng...

AI Technical Summary

Problems solved by technology

However, most of the existing research focuses on the mechanism and force of the two tools when the scraper cuts soft soil strata and the hob breaks rock. Sand and pebble strata are characterized by strong abrasiveness and strong discreteness. Practical engineering experience It is shown that the scrapers and hobs commonly used in shield tunneling are not effective in the highly abrasive and discrete sand and pebble formations: when the scraper is used as the main cutting tool, the tool wears quickly and the thrust torque required for cutting is high; When the knife is used as the main cutting knife, the rotation of the hob is blocked, which is likely to cause partial wear failure, and the compound cutterhead with the hob has a small opening ratio, which is not conducive to the dredging of pebbles and gravel

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