Modeling of excess shear stress around two columns of tandempiers of longitudinal bridge(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2021年4期
- Page:
- 32-42
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Modeling of excess shear stress around two columns of tandempiers of longitudinal bridge
- Author(s):
- QI Hongliang; YUAN Tiangang; TIAN Weiping; ZHANG Chenguang
- （Key Laboratory for Special Area Highway Engineering of Ministry of Education,Changan University, Xian 710064, Shaanxi, China）
- Keywords:
- bridge engineering; two columns of tandem piers; excess shear stress; longitudinal bridge; numerical simulation; computational fluid dynamics
- PACS:
- -
- DOI:
- -
- Abstract:
- To reveal the mechanism of the influence of the longitudinal bridge pier span on the characteristics of the excess shear stress near the riverbed, FLOW3D was used to simulate the excess shear stress near the river bed with a fixed bedload and two columns of tandem piers in the straight river, based on the design of pier of the Xihan (Xian to Hanzhong) Highway. The influence of the diameter of cylindrical pier on the length of the downstream caused by vortex street was analyzed. The influence of the span on the excess shear stress characteristics of the horizontal plane near the river bed, the excess shear stress characteristics of each crosssection at the center of the bridge pier, and the maximum excess shear stress characteristics near the bridge piers were analyzed. The critical span that significantly affects the characteristics of the excess shear stress near the river bed was proposed. The results show that when the pier span is shorter than 28.5D (D is the diameter of the pier in the model), the accumulative effect of the Kármán vortex street has a significant impact on the characteristics of the excess shear stress. The closer the location to the downstream is, the more obvious the influence is. Compared with the crosssection of the first row in each model, the excess shear stress around other crosssections reduce up to 50%, and the excess shear stress between the piers and the river bank increases up to 54%. In different models, the coefficient of the maximum excess shear stress of the first row of piers is about 0.95, and it is not affected by the span of the models. The shorter the span is, the more obvious the shielding effect of the tandem pier is. When the span is short than 28.5D, the coefficient of the maximum excess shear stress of the first three rows decreases rapidly from 0.95 to 0.58, and finally stabilizes at about 0.5. When it is longer than 28.5D, the coefficient of the maximum excess shear stress of the first two rows of piers decreases rapidly from 0.95 to 0.72, and finally stabilizes at about 0.7. 2 tabs, 10 figs, 33 refs.
Last Update: 2021-08-12