DTS-based design method of detection system for detecting integrity of cast-in-place pile

Abstract

The invention discloses a DTS-based design method of a detection system for detecting the integrity of a cast-in-place pile. According to the DTS-based design method, linear optical fibers are planted into a pile body with the cross radius of the pile of R and are distributed along the central line; the planted optical fibers are used as an inner heat source and are heated; an influence radius of heat conduction is r0, Ts is a rock and soil medium temperature, and temperatures of the pile body and an outer surface are equal to the rock and soil medium temperature under an initial condition; a critical radius r0 can be determined through distributing a plurality of optical fiber sensors at different distance parts in the pile body along the central line, and a heat conductivity coefficient k can be determined through a DRPL-II heat conductivity coefficient tester; optical fiber heating power q can be calculated through an equation according to known DTS instrument precision delta. According to the DTS-based design method disclosed by the invention, defect detection of the large-diameter concrete cast-in-place pile is taken as a research object and the proper quantity of the planted optical fibers is determined; the heating radiation critical radius r0 and the heating power q are calculated, so that evidences are provided for design indexes in a DTS detection process; rapid and complete detection can be realized, and the design method has prompting meanings on standard DTS pipe defect detection.

Description

technical field [0001] The invention relates to the layout design of temperature sensors for detecting the integrity of cast-in-situ piles based on heat conduction characteristics in the engineering field, and in particular to a detection system design method for detecting the integrity of cast-in-place piles based on DTS. Background technique [0002] At present, low-strain method, high-strain method, ultrasonic transmission method, static load test, etc. are mostly used in the integrity detection of cast-in-situ piles. These detection methods have the disadvantages of low efficiency, heavy equipment, large volume, real-time remote monitoring, and high cost. [0003] The detection technology based on distributed optical fiber sensing and temperature measurement uses ordinary optical fiber as the sensing and transmission medium, without adding other external sensor devices, and it has a certain degree of flexibility, which can maintain a certain degree of bending and embed i...

AI Technical Summary

Problems solved by technology

However, there is still no theoretical basis for the arrangement of optical fiber sensors in cast-in-situ piles and the determination of related parameters.

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