Inhouse destructive test of dismantled component of existing hollow slab bridge(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2019年06期
- Page:
- 57-66
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Inhouse destructive test of dismantled component of existing hollow slab bridge
- Author(s):
- QU Guangzhen; ZHOU Guangli; HUANG Pingming; HAN Wanshui; GONG Wenlong; YUAN Yangguang
- (1. School of Highway, Chang’an University, Xi’an 710064, Shaanxi, China; 2. Shandong Transportation Research Institute, Jinan 250012, Shandong, China; 3. School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, Shaanxi, China)
- Keywords:
- bridge engineering; existing hollow slab bridge; destructive test; whole process analysis on static and dynamic characteristics; modal flexibility difference; bearing capacity
- PACS:
- -
- DOI:
- -
- Abstract:
- ?In order to accurately assess the residual bearing capacity of the hollow slab beam after 24 years of service, a hollow slab girder bridge of Jiqing Highway Reconstruction Project was demolished and transported to the laboratory for failure test. The key position static response indicators such as beam deflection, steel strain, concrete strain, crack development etc, of the hollow slab were tested during the whole test, and the dynamic characteristics of the beam under the main load step were tested too. The results show that the midspan vertical displacementmoment curve as an obvious double folding line change. The bending moment corresponding with the actual plastic turning point are 2.5 times and 4.09 times as the design values of two kinds of design vehicle loads, Highwayclass Ⅰ and Aubomobileover 20 respectively. The entering to plastic stage of the hollow slab is mainly caused by the yielding of part of the tensile reinforcements. During the destructive test, the neutral axis of the slab shift up about 6.9 cm from the original location, which induce that the compressive strain of the concrete of the superior border firstly increasing with the loading level and then decreases. Before entering the plastic stage, the width of the main crack of the web increase relatively slowly and is basically below 0.3 mm, and then the crack grow quickly, however the growth of the midspan bending moment is slow. In terms of dynamic characteristics, the selfvibration frequency of the hollow slab in the preliminary test is weak, and after entering the plastic working stage, the firstorder frequency of the hollow slab decrease significantly. Based on the modal flexibility difference, the hollow slab damage before entering the plastic working stage can be further quantified. The actual flexural capacity of the hollow slab beam which determined by the failure test is 1.52 times the normal calculated bearing capacity.
12 figs, 26 refs.
Last Update: 2019-12-19