Underground structure health monitoring method based on thermal expansion coefficient and load strain

Abstract

The invention discloses an underground structure health monitoring method based on a thermal expansion coefficient and load strain. The method comprises the following steps: arranging temperature and strain sensors on the inner surface of an underground structure; collecting temperature and strain monitoring data of the underground structure; calculating load strain and a thermal expansion coefficient; solving a normalized thermal expansion coefficient, and establishing four thermal expansion coefficient Euclidean distance matrixes; and studying and judging the underground structure damage according to the load strain and the Euclidean distance matrix change of the previous and later evaluation periods. According to the method, the influence of sensor errors can be eliminated to a greater extent, the structural damage identification is more sensitive and accurate, strain and temperature sensor data commonly used in existing monitoring can be fully utilized, and the cost of data acquisition is not additionally increased.

Description

technical field [0001] The invention relates to the technical field of underground structure health monitoring, in particular to an underground structure health monitoring method based on thermal expansion coefficient and load strain. Background technique [0002] In recent years, with the rapid development of my country's infrastructure, the development of underground space is in full swing. However, the concrete underground building structure after completion is buried underground, the working environment is complex and changeable, and the external load changes greatly and is difficult to predict. Cracking, water leakage, corrosion of steel bars, partial cracking of concrete, and even major disasters of overall collapse often occur in underground building structures. This has aroused great attention from the management and maintenance units of underground structures. How to effectively monitor damage to underground structures has become an important task. Major technical ...

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Problems solved by technology

However, these sensors can only reflect changes in specific monitoring content at specific points and local areas. To reflect the state of the entire structure, a large number of sensors need to be deployed in the space, which greatly increases the cost of monitoring and the difficulty of equipment installation.

The increasingly widely used fiber optic sensors can better cover a large range of monitoring needs with a continuous fiber optic, but they are expensive, easy to damage, and the monitoring content is relatively single

The Chinese invention patent "EMD-Based Structural Stiffness Damage Monitoring Method and System" authorized on 2017.07.18 discloses a method for evaluating the degree of structural stiffness damage based on monitoring structural vibration response, especially suitable for small structural stiffness damage under impact loads Monitoring and judgment; In addition, there are similar patents or research results to identify structural damage based on the vibration of the structure under external force, but underground structures generally do not directly bear external impact loads, and underground structures do not appear under normal external loads Obvious vibration, so it is not effective to evaluate the stiffness damage of underground structures through vibration monitoring

The Chinese invention patent "A Method for Identifying Damage of Long-Span Bridges" authorized on 2017.04.26 discloses a method for identifying damage to bridge structures based on temperature strain, but this method requires sensors to be placed on the cross-section, and the built-up underground In the structure, sensors can only be arranged on the surface, and sensing balls cannot be arranged in the structure section, so this method cannot be applied to underground structures

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