Muck improvement method based on cobble and boulder stratum shield engineering characteristic classification

Abstract

The invention discloses a muck improvement method based on cobble and boulder stratum shield engineering characteristic classification. The muck improvement method comprises the following steps: determining the maximum particle size and content of particles in a stratum according to geological exploration data; calculating the transportable and dischargeable characteristic particle size of a selected screw conveyor; dividing the boulders into huge boulders and small boulders according to the drainage characteristic particle size; according to the problems encountered in the shield tunneling construction process, dividing the cobble and boulder stratum shield engineering characteristics into cobble and boulder soil, fine-grain cobble and boulder-containing soil, cobble and boulder-containing gravel soil and cobble and boulder-containing clay; and taking corresponding muck improvement measures for the soil layer according to the classified cobble and boulder stratum shield engineering characteristic classification. According to the method, a particle group division mode of characteristic particle sizes is carried out, and meanwhile, shield characteristic division is carried out on the cobble and boulder stratum according to problems encountered in shield construction, and a control technology for muck improvement is provided in a targeted mode, so that the shield construction efficiency is improved, and the probability of engineering accidents is reduced.

Description

technical field [0001] The invention relates to the technical field of shield tunneling, in particular to the improvement technology of dregs in shield construction, in particular to a dregs improvement method based on the classification of characteristics of shield tunneling in pebble boulder formations. Background technique [0002] Shield construction has the advantages of high degree of mechanization, less impact on ground buildings, and safe construction. It is widely used in domestic urban underground rail transit, underground comprehensive pipe gallery construction and other projects. It is generally believed that the earth pressure balance shield is suitable for formations with rock and soil conditions ranging from clay to sand and medium gravel. When the pressure exceeds 2bar, the permeability coefficient of water should not exceed 10 -5 m / s. The sandy pebble formation is a typical mechanically unstable and highly abrasive formation, which has the characteristics o...

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Problems solved by technology

The existing muck improvement technology is basically based on the soil category, and the classification of soil in practice and norms is generally based on particle size and content to define the various classifications of soil. This classification principle is used in shield tunneling construction. It does not have much guiding significance, because in different projects, different types of soil layers may encounter different problems during shield tunneling construction, and when different soil layers face different construction problems, their muck improvement methods are also different. However, none of the existing technologies consider stratum classification from the perspective of shield type selection, construction technology and construction requirements, and take targeted improvement measures based on stratum classification, especially the classification method and control technology of egg drift strata. Therefore, it is necessary to Carry out research to make the muck improvement measures more targeted, better able to guide shield tunneling construction, and effectively solve various problems encountered in shield tunneling construction

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