A monitoring method for a surrounding rock and full face tunnel boring machine shield interaction process

Abstract

The invention provides a monitoring method for a surrounding rock and full face tunnel boring machine shield interaction process. The method comprises the steps of: A, welding and installing pressure boxes to the outer surface of a shield for testing the extrusion force applied to the shield by surrounding rocks directly, placing cables of the pressure boxes in flexible cable-protecting casing pipes, and leading the cables into the shield and connecting the cables to a reading device; B, installing a surface strain sensor in each of the annular direction and the longitudinal direction of each monitoring point on the inner surface of the shield, and inversely calculating the extrusion force applied to the shield by the surrounding rocks according to the principle of elastic mechanics based on the tested annular and longitudinal strains of the inner surface of the shield; C, according to the acquired distribution rules of the extrusion force applied to the shield by the surrounding rocks, calculating the friction force borne by the shield on the premise of linear distribution of the extrusion force between two adjacent measuring points; D, according to the jamming state judging criteria and jamming risk coefficient calculation method, calculating whether the shield is jammed and giving early warning of a jamming risk level. The method solves the problem in monitoring of surrounding rock and shield interaction in a shield type TMB tunneling process, provides basis for the predictive analysis of jamming accidents and is of great importance for the safety of TBM tunneling.

Description

technical field [0001] The invention relates to the field of monitoring methods for the interaction between surrounding rock and supporting structures, and more particularly relates to a method for monitoring the interaction process between surrounding rock and TBM shields under the condition of TBM excavation, which can also be used to test the load of surrounding rock on other supporting structures. Background technique [0002] The shield-type full-face tunnel boring machine (TBM) can make the excavation and installation of segments synchronous, with high excavation efficiency and safe construction, and is widely used in tunnel excavation. However, in the construction of deep-buried long tunnels and deep shaft roadways, TBM often needs to cross some weak and broken rock formations with high ground stress, and the surrounding rock is prone to large deformation. When the deformation of the surrounding rock in the shield area exceeds the deformation gap between the surroundi...

AI Technical Summary

Problems solved by technology

[0003] (1) Since TBM manufacturers do not have testing requirements, they are not equipped with sensors for testing the extrusion force of surrounding rocks when they are designed and manufactured.

[0004] (2) The construction unit often takes passive measures to relieve difficulties when there is a jamming accident, and rarely conducts real-time monitoring of the deformation of the surrounding rock and the extrusion force of the surrounding rock on the shield in advance

[0005] (3) Since the reserved deformation gap between the surrounding rock and the shield is very small, usually 5-10cm, the observation space is narrow, and as the TBM continues to excavate, the shield and the surrounding rock will slip relative to each other. It is difficult to install sensing and monitoring equipment in this small observation space. Even if some flat and thin sensors are installed, the uneven surrounding rocks that are touched when the shield moves forward with the TBM excavation will be scratched and dropped. Or collapse, so there is currently no test method that specifically tests the interaction process between the surrounding rock and the shield

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