Method for detecting steel tube void of concrete filled steel tube (CFST) arch bridge by utilizing transient impact method

Abstract

The invention provides a method for detecting steel tube void of concrete filled steel tube (CFST) arch bridge by utilizing a transient impact method; the method provided by the invention is characterized by comprising the following steps: 1, arranging measuring points, axially arranging a plurality of measuring points at the outer wall of a steel tube which is made of a CFST and is to be detected, and placing an acceleration transducer on each measuring point; 2, arranging a vibration excitation point at the outer wall near to the head end or tail end of the steel tube, horizontally knockingthe vibration excitation point by a vibration excitation device, and detecting the acceleration response signals of the measuring points by the acceleration transducer; 3, outputting the response signals of the measuring points by the acceleration transducer, inputting the signals into a data collector by a signal amplifier, obtaining the natural frequency and acceleration power spectral density of each measuring point by the data collector, and storing in a computer. In the invention, the steel tube void of the CFST arch bridge can be located fast and exactly according to the natural frequency and power spectral density of acceleration response and via calculating and comparing the acceleration spectral energy values of the measuring points based on an expression.

Description

technical field [0001] The invention relates to a method for detecting the emptying of steel pipes of concrete-filled steel pipe arch bridges, in particular to a method for detecting emptying of steel pipes for steel pipe concrete arch bridges by using a transient impact method. Background technique [0002] Concrete-filled steel tube arch bridges are widely used in my country, but due to the characteristics of concrete materials and pumping construction techniques, defects such as voids and holes in the concrete-filled steel tube interface often occur, which directly affect the quality of the arch bridge and pose a safety hazard. , the concealment of cracks and the randomness of time and space in their development, and the technical difficulty of their effective detection (no omission, quantification) is very high. Engineering safety. [0003] At present, domestic damage detection and nondestructive testing methods have their own limitations. The drilling and coring method ...

AI Technical Summary

Problems solved by technology

The drilling and coring method randomly selects a certain detection point for the component to open a hole, and the extraction of the concrete core sample inside will cause damage to the component itself; the artificial percussion method can only qualitatively judge the bonding status of the steel pipe wall and the concrete from the sound echo, which is different from The experience of the operator has a lot to do with the subjective judgment, and there is no effective basis; the ultrasonic method is a common non-destructive testing method, but due to the complexity of the shape of the test piece, such as small size and irregular shape, the reliability of ultrasonic testing Implementability has a greater impact

The internal structure of the material, such as non-uniformity and non-compactness, will make the sensitivity and signal-to-noise ratio of ultrasonic testing worse, so it is difficult for ultrasonic testing to effectively identify the shape and type of defects.

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