Pile foundation defect detection and repair method for cast-in-situ bored pile

Abstract

The invention discloses a pile foundation defect detection and repair method for a cast-in-situ bored pile. The method comprises the key steps that when a heating element (5) is located at a certain depth, if the waveform peak value of only one thermal inductance optical fiber (4) declines, it is judged that a cavity is formed in a pile body (1) at the depth, and the cavity is located at the position, passing through the radius of the abnormal thermal inductance optical fiber (4), of the cross section of the pile body (1); when the heating element (5) is located at a certain depth, if the waveform peak values of two adjacent thermal inductance optical fibers (4) decline, it is judged that the cavity is formed in the pile body (1) at the depth, and the cavity is located on a sector face formed by two radii passing through the two abnormal thermal inductance optical fibers (4); when the heating element (5) is located at a certain depth, if the waveform peak values of all thermal inductance optical fibers (4) decline, then it is judged that pile breaking exists at the depth. By means of the method, no missing detection is caused, the longitudinal depth of a broken pile at each layer can be detected accurately, the longitudinal depth of each cavity and the transverse locations, located on the cross section of a pile foundation, of the cavities can be detected, and effective repair can further be conducted on each defect.

Description

technical field [0001] The invention relates to the field of health monitoring of bored cast-in-situ piles in civil engineering, in particular to a method for detecting and repairing pile foundation defects of bored cast-in-situ piles. Background technique [0002] Due to the unfavorable factors such as high noise and environmental impact of piling, bored piles are generally used in urban construction with dense buildings. However, the quality of bored piles is affected by factors such as geographical environment, mechanical equipment, and human misoperation, which are prone to pile foundation defects, that is, broken piles or holes in the pile foundation concrete. [0003] In the prior art, the low-strain stress wave method is generally used to detect pile foundation defects. This detection method is based on the theory of elastic reflection. , to generate a stress wave that propagates vertically in the pile body. When there is a defect in the pile body, such as when the s...

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Problems solved by technology

[0004] The method for detecting pile foundations in the prior art has the following disadvantages: 1. This method is particularly easy to miss holes, because the area of ​​the induction probe is small, and the range of the pile foundation signal actually collected is only the point where the probe is located vertically downward. For the convenience of expression, this line is called the sampling vertical line. If the hole is exactly on the sampling vertical line, it can be detected. However, in most cases, the hole is not located on the sampling vertical line, so there is no way to perceive it. In fact, the The method is only relatively sure for the detection of broken piles; 2. If there are multiple pile foundation defects of different heights on the same sampling vertical line, such as multiple cavities, or multi-layer broken piles, or both broken piles and cavities, Then the stress wave will be reflected and transmitted at each defect, and multiple defects located on the same sampling vertical line interfere with each other. It is impossible to know the number of broken piles and cavities, and it is also impossible to know the depth of broken piles and cavities, that is, the detection results are quite inaccurate and the detection effect is poor; 3. The existing technology lacks effective means to detect pile foundation defects. make repairs

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