Centrifuge model test on effect of underground loess cave on vertical bearing characteristic of bridge pile foundation(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年02期
- Page:
- 35-44
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Centrifuge model test on effect of underground loess cave on vertical bearing characteristic of bridge pile foundation
- Author(s):
- FENG Zhong-ju; WANG Fu-chun; SU Hang-zhou; HAN Qiu-shi; XI Chen-xin; LI Yan; YIN Hong-hua; JIAN Xin-lon; LIANG Qian
- 1. School of Highway, Chang’an University, Xi’an 710064, Shaanxi, China; 2. Power China Northwest Engineering Corporation Limited, Xi’an 710065, Shaanxi, China; 3. Technical Center of China Construction Seventh Engineering Division Co. Ltd., Zhengzhou 450004, Henan, China; 4. Guangdong Nanyue Transportation Investment & Construction Co. Ltd., Guangzhou 510507, Guangdong, China; 5. Guangdong Province Communications Planning & Design Institute Co. Ltd., Guangzhou 510507, Guangdong, China
- Keywords:
- bridge engineering; loess cave; bridge pile foundation; vertical bearing characteristics; centrifuge model test
- PACS:
- U443.15
- DOI:
- -
- Abstract:
- Due to the lack of enough reference on design calculation method and construction technology of bridge pile foundation in loess region with underground caves, loess caves are blindly treated before construction on the condition of bridge pile foundation with loess underground caves, which can not guarantee the security of pile and is also uneconomical. According to the centrifugal model test with Aluminum tube simulating pile and expandable polystyrene (EPE) plastic foam simulating loess cave, the influence of loess underground caves on vertical bearing characteristic of bridge pile foundation was studied. Under the action of vertical load, the effect of some factors on vertical bearing capacity of bridge pile foundation, axial force of pile shaft and pile side friction resistance were analyzed. These factors include the horizontal spacing between pile and cave, the depth of cave development and the vertical spacing between pile bottom and cave. The results show that when the depth of cave development is less than 20 m and the horizontal spacing between pile and cave is larger than 1.0 times of the pile diameter, or the horizontal spacing of pile and cave is larger than 20% of pile diameter and the depth of cave development is less than 5 m, or the vertical spacing between pile bottom and cave exceeds 8 m, the vertical ultimate bearing capacity is less affected by the cave. With the increase of horizontal spacing between pile and cave, the vertical ultimate bearing capacity of pile foundation is gradually increased. The smaller the horizontal spacing, the smaller the pile side friction resistance and the larger the axial force of pile shaft. With the gradual increase of vertical spacing between pile bottom and cave, the vertical ultimate bearing capacity of pile foundation also increases. The smaller the vertical spacing, the bigger the pile side friction resistance, and the smaller the axial force of pile shaft. Under the same load, the smaller the horizontal spacing between pile and cave, the deeper the depth of cave development and the smaller the pile side friction resistance. The smaller the load of pile top, the smaller the vertical spacing between pile bottom and cave and the bigger the pile side friction resistance. The results can provide design technical basis for bridge pile foundation in loess region with underground caves.
Last Update: 2017-04-07