FBG传感器在深基坑支撑应变监测中的应用  

Strain monitoring of interior bracing in deep foundation pit by FBG sensors

作　　者：黄广龙[1] 张枫[1] 徐洪钟[1] 陈贵[2] 

机构地区：[1]南京工业大学土木工程学院,江苏南京210009 [2]江苏省建筑科学研究院有限公司,江苏南京210008

出　　处：《岩土工程学报》2008年第S1期436-440,共5页Chinese Journal of Geotechnical Engineering

基　　金：江苏省科研院所技术开发专项基金项目(BM2005517)

摘　　要：将光纤布拉格光栅(FBG)传感器用于深基坑钢筋混凝土支撑应变监测,得到了基坑开挖时混凝土内支撑全程应变曲线。考虑温度对应变的影响,采取相应的温度补偿措施,提高了应变监测的精度,测试结果与振弦式钢筋计监测结果具有很好的一致性,表明FBG传感器用于基坑支护结构内力监测是可行的。监测结果显示混凝土内支撑上下部处于不同的受力状态,以往采用断面平均应力法计算支撑轴力是不合理的。The strain monitoring of reinforced concrete bracing structure was carried out by using fiber Bragg grating sensors, and the whole strain curves of interior bracing were obtained in the course of different situations of foundation pit excavation. Considering the temperature effect,the solution of temperature compensation was taken in order to achieve higher precision in the strain monitoring by FBG sensors,and the measuring results were well consistent with those results measuring by using vibrating wire steel meters.Thus it was appropriate to use FBG sensors in monitoring the strain of bracing structure in foundation pit excavation.The measured results indicate that the stress state is different in diverse part of the bracing beams,so it is not feasible to take an average to strain measures in calculating the axial force and deformation of reinforced concrete braces of supporting structures.

关 键 词：FBG传感器 深基坑 内支撑 应变监测 

分 类 号：TU46[建筑科学—结构工程]