Effect of loess gully slope terrain on bearing performance of pile foundation(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2016年06期
- Page:
- 62-68
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Effect of loess gully slope terrain on bearing performance of pile foundation
- Author(s):
- LUAN Juan; HAO Xian-wu; ZHAO Bao-jun
- 1. School of Highway, Chang’an University, Xi’an 710064, Shaanxi, China; 2. Shaanxi Provincial Communication Construction Group, Xi’an 710075, Shaanxi, China
- Keywords:
- bridge engineering; pile foundation; loess gully; slope; slope distance; ultimate bearing capacity
- PACS:
- U443.15
- DOI:
- -
- Abstract:
- With more and more highway bridges crossing complicated terrains in Western China, the problem that bridge pile foundation in loess gully terrain is influenced by relatively complex external loads is more and more obvious. Pile side soil is asymmetry due to the lack of effect of soil around pile. Side friction near the side slope soil is difficult to play an effective role, thereby reducing the vertical bearing capacity of pile foundation. For this problem, this paper combined with the engineering geological characteristics of the western loess gully terrain steep slope. Contact analysis of interface between pile and soil for studying the geological survey data of construction project in loess area of Northern Shaanxi through MIDAS FEA were conducted. Influence of loess gully terrain steep slope on pile foundation bearing force was studied, and the influence regularities of two main factors-slope and slope distance on it were summarizes. The results show that the ultimate bearing capacity of pile foundation is inversely proportional to slope. When the slope is 30°, the bearing capacity of pile foundation decreases by 13.2% compared with the bearing capacity of pile, the side friction resistance of pile decreases by 18.3%, and the resistance of pile end decreases by 2.3%; When the slope is 70°, the bearing capacity reduces by 46.7%, the friction resistance of pile decreases by 64%, and the resistance of pile decreases by 9.8%; With the increase of slope distance, the resistance change of pile is small, and the side resistance of pile increases significantly. When slope distance increases from D (pile diameter) to 8D, the ratio of pile tip resistance to ultimate bearing capacity decreases from 59% to 49%, which is basically stable; When side resistance of pile increases from D to 2D, side resistance of pile increases by 25%. Therefore, slope factor should not be ignored in engineering practice. The research results can provide references for design and construction of bridge pile foundation.
Last Update: 2016-12-02