Concrete filled steel tube debonding and empty comprehensive judgment method based on real-time monitoring data

Abstract

The invention discloses a concrete filled steel tube debonding and empty comprehensive judgment method based on real-time monitoring data, and the method comprises the steps: determining a key section which is liable to cause concrete filled steel tube debonding and empty as a monitoring section through theoretical calculation and previous practical engineering experience, wherein the real-time monitoring content of a single monitoring section comprises three parts of in-tube concrete three-direction strain monitoring, in-tube concrete temperature monitoring and steel tube wall two-direction strain monitoring; carrying out real-time strain monitoring and comparison of in-pipe concrete and the steel pipe wall in real time; and comprehensively judging whether the steel pipe inner core concrete and the steel pipe wall are debonded or even empty or not through strain comparison in the radial direction, the annular direction and the axial direction. By means of the comprehensive judgment method, the debonding (empty) condition of the concrete in the steel tube can be accurately judged, and the pouring condition of the concrete in the steel tube can be known.

Description

technical field [0001] The invention relates to a comprehensive discrimination method for debonding voids of concrete filled steel pipes based on real-time monitoring data, in particular to a comprehensive discrimination method for debonding (voids) of steel pipe concrete based on real-time monitoring data of optical fiber gratings. Background technique [0002] The concrete-filled steel tube arch bridge has many advantages such as light weight, high strength, and strong deformation resistance. In the past ten years, in the field of transportation, especially in the southwest canyons, the number of concrete-filled steel tube arch bridges has risen sharply. The number of long-span concrete-filled steel tube concrete arch bridges of more than 100m that has been built or is under construction in my country has reached 252 by September 2017, with an average of 9 per year. increase. [0003] However, what does not match the rapid increase in engineering construction is that the l...

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Problems solved by technology

[0003] However, what does not match the rapid increase in engineering construction is that the load-bearing characteristics of the binary material such as concrete-filled steel tubes have not been studied clearly. The load-bearing mechanism between the two is based on the premise of collaborative deformation, but in actual engineering It is found that due to the hardening of the concrete in the tube, the debonding (voiding) phenomenon will occur to different degrees, and the time point of occurrence may occur during the construction period or during the later operation period

Ultrasonic method, percussion method and other methods are often used for on-site inspection when the construction is completed, which can only evaluate the state at the moment of inspection, and cannot consider the change of the bonding interface between the two over time

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