A health monitoring method for non-embedded structure of shield tunneling method

Abstract

The invention discloses a non-preburied structure health monitoring method for a shield tunnel. The non-preburied structure health monitoring method comprises the steps of: for a tunnel section havinga construction defect, measuring and calculating segment arc-shaped surface length variation values of a segment in different stress states; for a defect section, performing inverse analysis of an internal force based on the segment arc-shaped surface length variation values to obtain a final internal value map; and determining whether the section has the necessity of long-term monitoring according to the inverse analysis result, installing sensor components in a targeted manner, and monitoring the structrual stress state of the section for a long time. From the perspective of long-term health of the structure, the sections which are most dangerous and most in need of long-term monitoring are often the defect sections with damage, fracture, severe slab staggering and the like caused by various reasons in construction, positions of these ''defective sections'' are difficult to forecast due to the randomness of construction factors, but the non-preburied structure health monitoring method can monitor the positions which are most dangerous and most in need of monitoring precisely through pre-burying elements and components later.

Description

technical field [0001] The invention belongs to the field of tunnel engineering, and in particular relates to a health monitoring method for non-embedded structures of shield tunnels. Background technique [0002] The shield method tunnel has the advantages of fast construction speed, environmental protection, and economy, but its special structural form makes it have the remarkable characteristics of small overall rigidity and weak deformation resistance. After the surrounding strata are disturbed, cracking, leakage, and lateral Significantly increased deformation, longitudinal uneven settlement and other diseases, in recent years, reports on various diseases of shield tunnels are not uncommon. Therefore, shield tunnel health monitoring technology is gradually being widely used in this field, trying to realize long-term monitoring of structural stress conditions to evaluate the safety status of tunnels. [0003] However, the existing structural health monitoring technology...

AI Technical Summary

Problems solved by technology

However, from the perspective of long-term structural health, the sections that are most dangerous and require long-term monitoring are often those sections that are damaged, cracked, or severely misaligned due to various reasons during construction (referred to as "defective sections"). The location of these "defective sections" is difficult to predict, so it is also difficult to pre-embed components

[0005] 2) Difficult to achieve long-term monitoring

The survival rate of embedded components is difficult to reach 100%, and the service life is short (conventional mechanical measurement method is only 5-10 years, fiber grating components are about 15 years), and it is basically impossible to achieve replacement and regeneration

[0006] 3) It is difficult to monitor the whole tunnel

For cost reasons, generally only a few sections are pre-embedded components, and it is impossible to pre-embed all segments

[0007] In addition, in terms of internal force inversion of shield tunneling tunnels, experts and scholars at home and abroad have adopted a method based on the convergence value of tunnel clearance evolved from mining tunnels. This method is more suitable for mountain tunnels, but shield tunnels use segment During the assembly process, there are misalignment and rotation between adjacent segments, so it is impossible to obtain accurate headroom convergence values, resulting in great errors in the internal force inversion results of segments, which cannot meet practical requirements

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