Shield tunnel structure damage assessment method

Abstract

The invention discloses a shield tunnel structure damage assessment method, which is characterized by comprising the steps of: establishing a shield tunnel structure model without a damage condition and a shield tunnel structure model with a damaged condition according to parameters of the shield tunnel, applying mobile load on the models to obtain a non-damage acceleration response signal and a damaged acceleration response signal of a measuring point; performing wavelet packet decomposition on the non-damage acceleration response signal and the damaged acceleration response signal separately to obtain wavelet packet energy of each frequency band; and determining a damage position and / or damage degree of the shield tunnel structure according to the wavelet packet energy of each frequency band and deviation of a vibration rate of an energy ratio. The shield tunnel structure damage assessment method adopts a damage identification method based on data, does not need vibration mode information of the structure, and can perform damage identification and assessment precisely by utilizing the accelerating signals before and after the structure is damaged.

Description

technical field [0001] The invention belongs to the technical field of civil engineering structure health monitoring and damage identification, and in particular relates to a shield tunnel structure damage assessment method. Background technique [0002] Tunnel structure is an important part of urban rail transit, once there is a problem, it will have a huge impact and loss on everyone's daily life. In practice, the service environment of underground tunnels is complex. With the increase of service time, local damage to the tunnel structure will inevitably occur. If inspection and maintenance are not carried out, hidden safety hazards will be left and severe accidents will occur. In fact, on the one hand, during the operation process, the reciprocating motion of the dynamic load such as the dynamic load of the vehicle may also cause different degrees of fatigue damage to the structure. On the other hand, building structures generally have unavoidable initial defects in cons...

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Problems solved by technology

This method is highly dependent on the mode shape information of the structure, but in fact it is relatively difficult to obtain the mode shape information; and although this method has certain advantages in solving small sample, nonlinear and high-dimensional pattern recognition problems, it is difficult to accurately detect damage When positioning and confirming the degree of damage, there are limitations

In addition, in the article "Research on Structural Damage Early Warning Method Based on Wavelet Packet Energy Spectrum", although the process of damage identification using the energy ratio and energy ratio change obtained by wavelet packet decomposition is discussed in detail, this method still has a large The error is large, and the error is relatively large in further accurate damage identification

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