摘要
对已经服役20年的既有预应力混凝土梁桥进行原位静载试验,确定测试断面及加载方案,逐级加载直至桥梁开裂破坏,获得主梁挠度及应变试验数据,对试验数据和理论计算数据进行对比分析,实现了对既有预应力混凝土梁桥现存预应力的评估。试验结果表明:在相同加载情况下,既有结构的受力变形和内力均大于理论计算值,结构的承载能力随桥梁服役期的延长而逐渐降低;对跨中截面进行卸载,其起拱值远远小于理论计算值;通过开裂应力和成桥状态理论计算应力的差值推算,发现经过20年的服役期,桥梁预应力相比成桥状态损失了约18. 8%。通过原位试验实现了对现存预应力的评估,这对类似的既有预应力混凝土桥梁的判断加固、拆除具有重要的借鉴意义。
The field test about static load of existing pre-stres concrete girder bridge which has serviced for 20 years is processed. The test data of deflection and strain of the main beam are obtained by loading step by step until the bridge cracks and destroys based on the loading program. Through the comparison and analysis of test data and theoretical calculation data,the extant pre-stressed force evaluation of the concrete beam bridge with existing pre-stress is realized. The test result shows that: under the same loading condition,the mechanical deformation and internal force of the structure are larger than the theoretical calculation value;the bearing capacity of the structure decreases gradually with the increase of the bridge servicing life;when the mid-span section is unloaded,the arch initiation value is far less than the theoretical calculation value;by calculating the difference between the cracking stress and the stress calculated by the bridge completion theory,it is found that after 20 years of service,the prestressing lose of the bridge is about 18. 8% compared with that of the newly built bridge. The extant pre-stressed force is evaluated by field test,which is of great significance for the judgement,reinforcement and demolition of the similar concrete bridge with existing pre-stress.
作者
黄颖
HUANG Ying(Fujian Chuanzheng Communications College, Fuzhou 350007, China)
出处
《四川理工学院学报（自然科学版）》
CAS
2019年第3期60-66,共7页
Journal of Sichuan University of Science & Engineering(Natural Science Edition)
基金
福建省教育厅应用技术协同创新中心项目(2018105)
关键词
桥梁
既有预应力
现存预应力
原位试验
损失评估
bridge
existing pre-stress
extant pre-stressed force
field test
loss assessment
