Test Research on Negative Skin Friction of Pile Foundation Under Special Immersion(PDF)
《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]
- Issue:
- 2018年04期
- Page:
- 105-112
- Research Field:
- Publishing date:
Info
- Title:
- Test Research on Negative Skin Friction of Pile Foundation Under Special Immersion
- Author(s):
- ZHU Yan-peng; YANG Kui-bin; WANG Hai-ming; YANG Xiao-hui
- School of Civil Engineering, Lanzhou University of Technology
- Keywords:
- special immersion; collapsible loess; pile foundation; negative skin friction; test research
- PACS:
- -
- DOI:
- -
- Abstract:
- In order to solve the problem of bearing capacity decrease of pile foundation caused by negative skin friction in collapsible loess areas, taking the elimination of collapsibility of loess around the pile as the starting point and exploring with new ways and methods, the field tests of concrete filled pile and micro steel pipe mortar composite pile were carried out respectively by using non-traditional special immersion methods. The results show that the immersion mode of water injection hole combined with test pit has a large amount of soaking water when the pile top is loaded. The negative skin friction of the pile side of soaking section is dominant, the max value is 319.62 kPa, and the local positive frictional resistance appears. The immersion mode of slurry circulation has a small amount of soaking water in the process of pile formation. The soil around the pile is partially collapsed before the pile top is loaded. The positive frictional resistance of the pile side is dominant after the pile top is loaded, the negative skin friction occurs on part of the pile side, and the value is smaller, the maximum value is 32 kPa. Under the special immersion condition, the soil around the pile will collapse discontinuously along the pile body. Multiple negative skin friction peaks and neutral points occur on the pile side, and the positive and negative frictional resistances are staggered. The negative skin friction of pile foundation is mainly affected by the mode of immersion, the mode of loading and the time of immersion consolidation. In order to avoid the decrease of the bearing capacity of the pile caused by the change of the groundwater environment, it is suggested to use reasonable construction technology to presoak the soil slightly around the pile to eliminate some loess collapsibility during the construction of pile foundation.
Last Update: 2018-07-18