基于分布式光纤传感器的预应力管道压浆质量检测  

Detection of Grouting Quality in Pre-stressed Ducts Using Distributed Fiber Optic Sensors

作　　者：龚士林 冯新[1] GONG Shi-lin;FENG Xin(State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China)

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《中国公路学报》2020年第7期86-94,共9页China Journal of Highway and Transport

基　　金：公路桥梁诊治技术交通运输行业研发中心开放基金项目(2018KFKT-08)。

摘　　要：现有预应力管道压浆质量检测方法多为点式测量,检测效率低,对检测环境要求高,并且易造成压浆缺陷漏检。为了弥补这一问题,提出一种基于分布式光纤传感器的预应力管道压浆质量检测方法。通过对预应力管道内压浆缺陷进行热力学分析,探讨与压浆密实度相关的热力学指标及其求解方法,并通过物理模拟开展试验研究,将设计的加热型分布式光纤传感器布设于预应力管道内部,采集加热后分布式光纤传感器的温度数据,识别温度分布曲线中的温度峰,计算各温度峰位置所对应的缺陷截面等效导热系数,分析该系数与压浆密实度的相关关系。研究结果表明:通过识别分布式光纤传感器温度分布曲线中的温度峰,可以将预应力管道中所有压浆缺陷准确识别出;缺陷截面的等效导热系数可以作为压浆密实度的评价指标,根据实测结果所得各位置的等效导热系数,可以近似求解出所对应的压浆密实度。Point-type measurements are generally applied for detecting the grouting quality of pre-stressed ducts.However,these types of measurements have several disadvantages that include low detection efficiency,high requirements for detection environments,and easy omission of grouting defects.To address these problems,a novel method of detecting the grouting quality in pre-stressed ducts using distributed fiber optic sensors was proposed.Grouting defects in pre-stressed ducts were first analyzed thermodynamically after which the thermodynamic indexes related to the grouting compactness were discussed,and the solving methods were assessed.Then,a physical simulation was conducted.Heating distributed fiber optic sensors were designed for placement in the pre-stressed ducts.Temperatures in these sensors were collected,and all temperature peaks in the temperature distribution curve were extracted.Finally,the equivalent thermal conductivity of the defect section at the location of the temperature peaks was calculated,and the correlation between the coefficient and grouting compactness was determined.The results indicate that,with the temperature peaks identified in the temperature distribution curve of the distributed fiber optic sensor,all grouting defects in the pre-stressed duct can be accurately determined.The equivalent thermal conductivity of the defect section can be used as an evaluation index of the grouting compactness.In addition,based on the equivalent thermal conductivity of each location obtained from the measured data,the corresponding grouting compactness can be approximated.

关 键 词：桥梁工程 压浆质量 分布式光纤传感器 温度 等效导热系数 

分 类 号：U446.3[建筑科学—桥梁与隧道工程]