多测点自感知预应力钢绞线在月亮湾大桥中的应用  

Application of Self-sensing Steel Strand with Multiple Measuring Points in Moon Bay Bridge

作　　者：李梦果 刘丰荣 吴尧 魏蔚 朱万旭[1,2] LI Meng-guo;LIU Feng-rong;WU Yao;WEI Wei;ZHU Wan-xu(College of Civil Engineering and Architecture, Guilin University of Technology, Guilin 541004, China;Guangxi Intelligent Structural Materials Engineering Research Center, Guilin 541004, China)

机构地区：[1]桂林理工大学土木与建筑工程学院,桂林541004 [2]广西智慧结构材料工程研究中心,桂林541004

出　　处：《科学技术与工程》2021年第29期12610-12615,共6页Science Technology and Engineering

基　　金：国家自然科学基金(52068014,51768014);广西科技计划(2018AA11010)。

摘　　要：精准监测体内索体应力是评估预应力结构安全的重要途径,为解决实际工程中体内预应力难以有效监测的问题,提出一种内嵌光纤光栅(fiber bragg grating,FBG)传感器的自感知钢绞线。通过张拉试验并结合月亮湾大桥实际应用,选用2根体内索作为预应力实时监测对象,对钢绞线逐级张拉至1395 MPa,在每根索的张拉端及索1/4跨处布置2个FBG测点。结果表明:自感知钢绞线的张拉非线性误差小于2.58%,应变灵敏度为1.09~1.13 pm/με,在工程应用中,自感知钢绞线中的传感器成活率达到100%,最大监测应变为7153με,最大监测应力为1394.79 MPa,与理论值1395 MPa误差仅为0.02%,可有效监测施工张拉和锚固全过程。可见自感知钢绞线能实现对体内索体应力精准、有效的实时监测。It's an important way to assess the safety of prestressed structures monitoring of internal cable body stress accurately.A self-sensing steel embedded with fiber bragg grating(FBG)sensors stranded wire was proposed to solve the problem that internal prestress is difficult to effectively monitor in actual projects.Through the tension test and combined with the actual application of the Moon Bay Bridge,two internal cables were selected as the real-time prestressed monitoring objects and tensioned step by step to 1395 MPa,two FBG measuring points were arranged at the tension end and the 1/4 span of the cable.The results show that the tension nonlinearity error of the self-sensing steel strand is less than 2.58%,and the strain sensitivity is about 1.09~1.13 pm/με.In engineering applications,the survival rate of the sensor in the self-sensing steel strand reaches 100%,and the maximum monitoring strain is 7153με,the maximum monitoring stress is 1394.79 MPa,and the error from the theoretical value of 1395 MPa is only 0.02%,which can effectively monitor the entire process of construction tension and anchoring.It is concluded that the stress of cable in the body can be real-time monitored by the self-sensing steel strand accurately and effectively.

关 键 词：自感知钢绞线 光纤光栅传感器 体内预应力 多测点监测 

分 类 号：TN253[电子电信—物理电子学] TU378[建筑科学—结构工程]