Cast-in-place concrete major-diameter pipe pile body strain monitoring method based on BOTDA

Abstract

The invention discloses a cast-in-place concrete major-diameter pipe pile body strain monitoring method based on BOTDA. The cast-in-place concrete major-diameter pipe pile body strain monitoring method is characterized in that a pair of vertical reinforcing steel bars are connected with arc-shaped reinforcing steel bars with arcs which are 1 / 4 of the circumference of a pipe pile to form carrier reinforcing steel bars. Grooves are formed in the carrier reinforcing steel bars, sensor fibers are embedded in the grooves, and the grooves are filled with epoxy resin. The pair of carrier reinforcing steel bars with optical fibers in an embedded mode are embedded in the cast-in-place concrete major-diameter pipe pile. Short pulsed light and continuous probe light are injected from the two ends of the sensor fibers with the BOTDA method, and strain information of points in the axial directions of the sensor fibers is obtained by measuring frequency changes of stimulated brillouin scattering light in the sensor fibers. The cast-in-place concrete major-diameter pipe pile body strain monitoring method has the advantages of being simple in construction wiring, resisting to interference, being high in accuracy and the like.

Description

technical field [0001] The invention relates to a test method of a foundation structure, in particular to a BOTDA-based method for monitoring the strain of a cast-in-place concrete large-diameter pipe pile body. Background technique [0002] The cast-in-place concrete large-diameter pipe pile is a new type of pile developed in recent years. Because the side friction is increased by expanding the pile diameter, the circular section of the pipe pile has an advantage in terms of concrete consumption compared with other piles. , the single pile has a high bearing capacity, and under the same bearing capacity requirements, the economic benefits are the best, and it has both the advantages of the reinforcement effect of rigid piles and the reinforcement cost advantages of flexible piles. In addition, the cast-in-place concrete large-diameter pipe pile saves the cost of pile transportation and pile sinking, and has a strong ability to penetrate the soil layer. The superior engineer...

AI Technical Summary

Problems solved by technology

Due to the complex installation and layout of strain gauges and low survival rate, continuous data on pile strain cannot be collected. At the same time, if too many strain gauges are embedded in the pile, multiple strain gauge data lines must be derived along the pile, which will affect the Integrity and strength of cast-in-place concrete large-diameter pipe piles, too many strain gauge connecting lines, and easy to knot

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