Loess strata subway tunnel earth pressure balance shield construction method

Abstract

The invention discloses a loess strata subway tunnel earth pressure balance shield construction method. The method comprises that firstly, shield excavation construction is performed by using a earth pressure balance shield machine; the excavation speed in no more than 10cm / min, the total thrust is no more than 15000KN, and the inner pressure of a soil warehouse is kept in a range between 1bar and 2 bar; the aperture opening ratio of a spoke panel type cutter is in a range of 40-70%, and the rotating speed of the cutter is no more than 1.5rpm; cement, pulverized fuel ash, fine sand, bentonite and water is mixed uniformly to obtain synchronous grouting liquid and second grouting is performed by using double-liquid grouting composed of cement paste and water glass; performing shield duct piece assembly construction after completion of one cycle of the shield excavation construction; and the process is repeated until the overall construction of the subway tunnel is achieved. The construction method is simple in step, easy to operate, fast in construction speed, high in construction quality, low in interference on the environment, high in construction safety and capable of guaranteeing successful construction of loess strata subway tunnels.

Description

technical field [0001] The invention relates to a subway shield construction method, in particular to an earth pressure balance shield construction method for subway tunnels in loess strata. Background technique [0002] The shield method is a fully mechanized construction method for modern tunnel construction. The main mechanical equipment used is the shield machine, which is divided into two types: earth pressure balance shield and mud-water balance shield. Among them, the earth pressure balance shield is used More often, the shield machine cuts soil and breaks rocks through knives during tunnel excavation. The earth pressure balance shield machine uses the full-section cutting cutter head installed at the front of the shield to cut off the front soil and enter the storage sealed cabin (i.e. soil bin) behind the cutter head, and make the cabin have an appropriate pressure It is balanced with the water and soil pressure on the excavation surface to reduce the disturbance o...

AI Technical Summary

Problems solved by technology

In the actual construction of shield tunnels in loess strata, there are mainly the following technical problems: 1) There are many types of loess strata, and the properties of various types of loess are quite different, so it is difficult to grasp the adaptability of shield machine selection; 2) In all kinds of loess The selection of excavation mode, the setting of excavation parameters, the selection of added materials, and the determination of the amount of addition are difficult; 3) It is difficult to grasp the characteristics of the deformation of loess strata caused by shield tunneling, especially when collapsible loess is used in shield construction conditions. The reflection of the ground and its deformation law and influence on land subsidence

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