Multi-working condition earth pressure balance shield muck workability test simulation test system

Abstract

The invention provides a multi-working-condition earth pressure balance shield muck workability test simulation test system. The multi-working-condition earth pressure balance shield muck workabilitytest simulation test system comprises a water supply system, a pressure air source, a test cylinder, and a shear rod, an axial loading device, a radial extrusion ring bag and a test bin pressure sensor which are arranged in the test cylinder, the test cylinder can simulate the working state of a soil bin of the earth pressure balance shield tunneling machine, the axial loading device is used for simulating different jacking forces of the shield tunneling machine, the radial extrusion ring bag is used for simulating the change of the soil discharge speed of a spiral conveyor, the water supply system is used for simulating the water pressure of different underground water environments, and a modifier adding system is used for a muck sample improvement test. According to the multi-working-condition earth pressure balance shield muck workability test simulation test system, the workability of the soil sample can be comprehensively tested under the condition that the water pressure and thesoil pressure change synchronously, and the research on the coupling influence of the water pressure and the soil pressure on the workability of the soil sample is facilitated; and soil sample workability parameters measured by the test system are more scientific and objective, and the test system better conforms to actual working conditions of shield engineering of special water-rich stratums such as underneath pass rivers and seas.

Description

technical field [0001] The invention relates to shield tunnel working condition simulation experiment equipment, in particular to a multi-working condition earth pressure balance shield tunnel dreg workability test simulation test system. Background technique [0002] In the construction of earth pressure balance shield, the workability of the test chamber dregs has an important influence on the safe and rapid excavation of the shield. In order to achieve the ideal workability, it is usually necessary to improve and optimize different dregs. The workability of the improved muck (that is, the improved performance of the muck) mainly includes three aspects: strength, deformation and permeability: specifically, lower strength to reduce the load on the cutter head torque and reduce the wear of the cutter head; moderate compression deformation characteristics In order to reduce the formation of mud cakes, etc., and increase the construction speed; the lower permeability can meet ...

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Problems solved by technology

[0003] Existing testing equipment for the workability of dregs and improved bodies has some defects in different degrees: ①The main tests for strength and deformation characteristics are direct shear instruments, triaxial instruments and confining compression instruments, but for dregs It is said that when the improver is increased by a certain amount, its flow plasticity is enhanced, and it is difficult to form a plastic sample for the above-mentioned equipment test; The test research on the coarse-grained and wide-graded muck soil samples; ③The existing soil permeability testing equipment mainly tests the permeability of muck under constant water head or variable head, but for water-rich properties such as under-passing rivers and seabed strata, etc. In terms of strata, it usually faces a high water-rich pressure of several hundreds of kilopascals; at the same time, in the water-rich stratum, the water pressure and soil pressure in the shield machine test chamber have mutual coupling effects, which will affect the workability of the muck. Existing infiltration equipment generally cannot exert earth pressure on the dregs during the infiltration test, and the workability of the obtained dregs will also lose objectivity

For example, Chinese patent 201610365907.7 discloses an experimental device and method for gushing prevention of earth pressure balance shield excavation in sandy gravel formation. Soil samples are subject to soil pressure and water pressure, so it is not suitable for simulation research on the construction conditions of earth pressure balance shield tunneling with rich water and high water pressure

Furthermore, the existing workability test of muck is mainly based on three aspects of independent testing, it is difficult to obtain the three indicators of strength, deformation and permeability through simultaneous testing, resulting in a large increase in the workload of testing experiments. At the same time, separate The initial state of the measured muck may not be the same due to the influence of errors in the preparation of muck samples during the test

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