夹泥灌注桩的光纤传感检测模型试验

Model Test of Mud-Intercalated Bored Pile Detection Based on Optical Fiber Sensing Technology

为了进一步提高灌注桩基检测水平,介绍基于分布式光纤传感技术的监测原理并设计相关的试验模型,制作含泥量分别为0,33.3%,50%,66.7%,100%的5种夹泥桩,对不同夹泥桩的光纤温升进行测量,分析不同夹泥桩中光纤温升规律,研究加热功率大小对光纤温升的影响及含泥量对光纤温升的影响。分析结果表明:温升与加热功率具有良好的线性关系;光纤温升随含泥量增加而增加,呈现先缓后快的增加规律;光纤温升与其所处桩身介质的结构和导热系数密切相关;该模型试验验证了分布式光纤传感技术用于夹泥灌注桩完整性检测的可行性,也可为基于该技术桩基检测的理论完善提供参考。

The principle of bored pile detection based on distributed optical fiber sensing technology is introduced in this paper and model test is carried out. Mud-intercalated bored piles with different clay contents（ 0,33. 3%,50%,66. 7%,100%） are prepared,and the optical fiber temperature rise in these piles are measured to analyze the rule of the temperature rise as well as the influences of heating power and clay content on optical fiber temperature rise. The results reveal a good linear relationship between heating power and optical fiber temperature rise.The temperature rise increases slowly firstly and then rapidly with the increment of clay content. It is also closely related with the structure and heat conductivity coefficient of pile medium. The model test in this paper verifies the feasibility of distributed optical fiber sensing technology in the detection of bored pile foundation.