Shield tunnel longitudinal internal force non-pre-buried type monitoring method

Abstract

The invention discloses a shield tunnel longitudinal internal force non-pre-buried type monitoring method. The shield tunnel longitudinal internal force non-pre-buried type monitoring method comprisesthe steps that aiming at a defective part or an environmental-change part, longitudinal lengths of a segment under different stress states are measured, and change values of the longitudinal lengthsof the segment are calculated; inverse analysis of internal force is carried out based on the longitudinal lengths of the segment and the length change values; and based on the inverse analysis results, whether a fracture surface has the necessity of long-time monitoring or not is judged, and monitoring components and parts are installed in a targeted mode so as to perform long-time monitoring onthe structural stress states of the fracture surface. According to the shield tunnel longitudinal internal force non-pre-buried type monitoring method, in terms of structural long-term health, the fracture surface which is really the most dangerous and needs to be monitored for a long time most is a defective position caused by various causes in construction in most cases, due to the fact that construction factors have randomness, defective positions are difficult to predict, environmental-change factors are further difficult to predict either due to plan changes or various special causes, andthe components and parts are difficult to pre-bury. According to the shield tunnel longitudinal internal force non-pre-buried type monitoring method, the components and parts are pre-buried in the later period, so that parts which are the most dangerous and need to be monitored most are monitored accurately.

Description

technical field [0001] The invention belongs to the field of tunnel engineering, and in particular relates to a non-embedded monitoring method for the longitudinal internal force of a shield tunnel. 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 monito...

AI Technical Summary

Problems solved by technology

However, from the perspective of long-term health of the structure, the section that is most dangerous to the longitudinal internal force of the structure and requires the most long-term monitoring is often the part that has subsidence or floating, cracked, or seriously misaligned due to various reasons during construction (referred to as "defective part") ), or the parts where the surrounding environment has changed greatly after construction (referred to as "environmental change parts"), due to the randomness of construction factors, the location of these "defective parts" is difficult to predict, and environmental change factors are also due to planning changes or various special The reason is also unpredictable, 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 the second method, since the measured longitudinal settlement (or uplift) deformation curve of the tunnel contains the inter-segment offset and it is difficult to eliminate its influence, there is a huge error in the internal force inversion results, which cannot meet the practical requirements

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