Study of Load Tests for Long-span Continuous Rigid Frame Bridge(PDF)
《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]
- Issue:
- 2017年04期
- Page:
- 105-111
- Research Field:
- Publishing date:
Info
- Title:
- Study of Load Tests for Long-span Continuous Rigid Frame Bridge
- Author(s):
- JIA Yi; BAI Lun-hua; JI Yun-tao; LI Jun-jin; YUAN Dong-mei
- School of Civil Engineering, Southwest Jiaotong University
- Keywords:
- load test; continuous rigid frame bridge; efficiency coefficient; natural vibration characteristic; calibration coefficient; load-carrying capacity
- PACS:
- -
- DOI:
- -
- Abstract:
- Based on a long-span continuous rigid frame bridge in Longling to Ruili highway, the bearing capacity and dynamic performance of the operating state were studied by field load test method. Firstly, arrangements of the strain, deflection and modal measuring point were introduced; then, test design load was determined based on load equivalent principle, and according to internal force distribution characteristics, the live load layout method of the most unfavorable positive and negative moments of the typical section was selected, and the static loading cases were determined, meanwhile dynamic load test program considering the influence of different speeds and running modes was established. Through the environmental excitation method, the modal results were obtained by using fast Fourier transform (FFT) in relevant instruments. Finally, the measured results and the finite element results were compared and analyzed. The results show that the static load test measured values of strain and deflection are less than the calculated values, and they can meet requirements of specifications; the dynamic load under the influence of impact coefficient is more sensitive to the traffic way, as when the speed is 20 km·h-1, impact coefficient of the main span of cross section is jumping to 0.25 compared with that of the uniform velocity 0.05, increased about 5 times; the overall loadcarrying capacity and stiffness of bridge structure meet the requirements of normal use under design load (highwaygrade Ⅰ).
Last Update: 2017-07-20