基于FBG传感技术的黏性土中静压沉桩阻力测试

为了探索光纤光栅(fiber Bragg grating,简称FBG)传感技术在黏性土中静压管桩沉桩阻力测试的适用性,在均质黏性土中进行了模型管桩静力压入试验。数据测试采用增敏微型光纤光栅应变传感器和双模式光纤光栅土压力传感器,基于FBG传感技术采集应变数据,分析沉桩过程桩端阻力和桩侧阻力贯入特性。通过改变桩长、桩径及开口和闭口,对比分析基于FBG传感技术的静压管桩的贯入过程差异。研究结果表明,FBG传感技术对黏性土中静压沉桩阻力的测试性能优越,能够准确体现静压管桩的贯入特性,清晰反映桩端阻力和桩侧阻力随桩径、桩长及开口和闭口的变化过程,这对静压管桩的模型试验与工程设计具有较大的参考价值。

Sinking Resistance of Jacked Piles in Clayey Soil Based on FBG Sensing Technology

In order to explore the applicability of fiber bragg grating (FBG) sensing technology for testing sinking resistance of jacked pipe piles in clayey soil, jacked model pipe piles are tested in homogeneous clayey soil. Miniature FBG strain sensors with enhanced sensitivity and dual-diaphragm FBG soil pressure sensor are used for data acquisition. Pile tip resistance and pile shaft resistance are analyzed during pile penetration based on FBG sensing technology for strain data acquisition. By changing the pile diameters, pile length, open-ended and close-ended pile, the difference of the penetration process of jacked pipe piles is analyzed for comparison based on FBG sensing technology. The results indicate that the requirement of FBG technology for testing of sinking resistance of jacked pipe piles in clayey soil can be wonderful satisfied. The sinking characteristics of jacked pipe piles is accurately demonstrated. Variation process of pile tip resistance and pile shaft resistance with various pile diameters, pile length, open-ended and close-ended pile are clearly reflected. The conclusion has major reference value for model test of jacked pipe piles and engineering design.