Steel tube centrifugal concrete pipe pile integrality endoscopic detection method

Abstract

The invention relates to a detecting method in geotechnical engineering and discloses an endoscopic detecting method of the integrity of a centrifugal concrete tubular pile of a steel pipe. The method of the invention comprises the following steps: a camera is suspended inside an orifice of the centrifugal concrete tubular pile of the steel pipe, wherein, the camera is connected with a computer through a waterproof cable, further connected with a scale string tape, and used for obtaining information inside the tubular pile orifice, displaying camera images on a computer screen, and storing the camera images inside a storage; the endoscopic camera images are processed so as to obtain information of underground water and concrete core as well as information of concrete surface quality inside the tubular pile orifice; recorded construction materials are input so as to obtain piling starting and halting information, recorded geological materials are input so as to obtain stratigraphic distribution and underground water information, and characteristic parameters of the detected pile are input; the computer implements the processing of the information, summarizes total defects of the detected pile, and calculates the integrity factor Beta of the detected pile. The endoscopic detecting method of the invention has the advantaged of convenient in-site operation, simple device structure and lower cost.

Description

technical field [0001] The invention relates to a geotechnical engineering detection method, in particular to a detection method for the integrity of steel pipe centrifugal concrete pipe piles. Background technique [0002] Steel pipe centrifugal concrete pipe pile is a newly developed concrete pipe pile. Due to the small diameter and hollow section of the pipe pile, there is no detection method for the integrity of the pile body. The industry standard of the People's Republic of China JGJ106-2003 "Technical Specifications for Building Pile Foundation Inspection" provides core drilling method, acoustic transmission method, low-strain dynamic measurement method and high-strain dynamic measurement method to detect the integrity of the pile body. The core drilling method is to directly detect the condition of the concrete of the pile body and the foundation of the pile end by drilling and taking cores along the axial length of the pile body, and it is only suitable for solid co...

AI Technical Summary

Problems solved by technology

Due to the small transient impact force applied by the low-strain dynamic measurement method, and the attenuation of the energy transmitted by the stress wave in the pile, the instrument cannot detect the reflected signal at the bottom of the pile or at a deeper level. The low-strain dynamic measurement method is only suitable for long-term Integrity detection of piles with small diameter or pile length less than 30m

Due to the large transient impact force imposed by the high-strain dynamic measurement method, the energy attenuation of the stress wave propagating in the pile is not enough to affect the reception of reflected signals at the bottom of the pile or deeper. The integrity of the pile body can be tested while resisting the compressive bearing capacity, but the high-strain variable test method is not convenient for on-site operation because it requires a transient impact force exerted by a 3-8 ton heavy hammer

Because the low-strain dynamic measurement method and the high-strain dynamic measurement method are based on one-dimensional wave theory analysis to determine the integrity of the pile body, the one-dimensional wave theory is not completely applicable to the heterogeneous material such as steel pipe centrifugal concrete piles. The integrity test results of the law are yet to be verified and corrected

[0003] Chinese patent 02139931.X discloses a method for measuring the compressive strength of centrifugal high-strength concrete of pipe piles by core drilling method. This method uses drilling to obtain a shorter core sample to detect the compressive strength of concrete in the pile body, and is only applicable to undriven piles. Or after excavation, the concrete compressive strength of the pile body near the top of the driven pile that can be exposed to the ground for core drilling and sampling operations is tested

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