Testing Research of Fiber Bragg Grating Strain Sensor Embedded in Bored Pile

Abstract

Reinforced concrete piles are used when structures are constructed on soft ground, because it is necessary to transfer the loads into deeper strata with a sufficient bearing capacity. With the purpose of receiving more precise information about the pile features, four fiber Bragg grating strain sensors are embedded at different levels of the pile to measure the strain distribution during straining and pull-out tests. Test Pile vertical uplift static load test results show that, settlement of the test pile is steep variations, the steep rise starting point corresponding to the load of 3300 kN for the Uplift Ultimate Bearing capacity, the corresponding uplift amount is 12.45 mm; 4.4 m, 7.2 m, 11.0 m and 14.5 m sections axial strain were 115 με, 42 με, 6 με and-3 με. Maximum loading capacity is 3600 kN, the corresponding uplift amount is 30.13mm; 4.4 m, 7.2 m, 11.0 m and 14.5 m sections axial strain were 142 με, 61 με, 7 με and-1 με.