Research on visual model test of displacement distribute characteristics and load transfer model of root pile during uplifting

doi:10.13225/j.cnki.jccs.2019.0962

	Research on visual model test of displacement distribute characteristics and load transfer model of root pile during uplifting
	Zhang, Jilu 1; Huang, Xuefeng 1,2; Wei, Linhui 1; Zhou, Junpeng 3; Yuan, Jun 4; Wang, Xueming 4
	2020-10-01
会议录名称	Meitan Xuebao/Journal of the China Coal Society
卷号	45
期号	10
页码	3435-3445
出版者	China Coal Society
摘要	In order to explore the uplift bearing characteristics of the roots pile, the non-intrusive test was used to measure the roots pile, the belled pile and the equal section pile which had same size with the deformation visualization system consisting of PIV(particle image velocimetry) technology and transparent soil. The test measured the Q-S curves of each pile and collected the images of change in the displacement field around the pile in real time. Based on the above images, the area of pixels with different color scales in the contour map of displacement field was calculated and compared to make the precise comparison of displacement field and plastic region of soil come true. At last, the test inferred the calculation model of soil side resistance of small-scale transparent soil model test pile with the support of the existing triaxial test results of transparent soil. The result shows that under the test condition, although the bearing capacity of the belled pile with the same size to the roots pile is higher, the roots pile with multi-layer shows a better control ability to the foundation displacement under the middle and low load, and it is more suitable for the building foundation with strict requirements on the displacement. There are optimization problems in the setting of root key. In order to ensure the full play of the bearing capacity of soil and root key, the space between two layers of roots should install at 4~6L(L is the length of roots). When the number of layers of roots is small, the effect of roots on load diffusion is not obvious, and the range of soil displacement field is even slightly lower than that of equal section pile. With the increase of the number of layers of roots, the range of soil displacement field around pile is also significantly expanded. Under the test conditions, the area of soil displacement field driven by the roots pile with 4 layers of roots is about 113% of that belled pile, while the area of plastic area is only 58% of belled pile. The improvement potential of the bearing capacity of the root key pile is better than that of the belled pile. Under the ultimate load, the shape of all displacement field of soil around pile is "inverted triangle", and the angle between the displacement field and the horizontal plane is (45 °+φ/2). The calculation model of pile-soil side resistance can reflect the law of foundation load transfer in certain extent supported by the existing research results of transparent soil. According to the calculation and analysis, the setting of roots and expansion head increase the ultimate bearing capacity of soil by 1.27 and 1.18 times respectively, and the setting of variable section makes the bearing capacity of soil to play a greater role. The depth effect on the normal resistance of roots is far less than that on the side frictional resistance. © 2020, Editorial Office of Journal of China Coal Society. All right reserved.
关键词	Bearing capacity Friction Particle size analysis Soils Velocity measurementBearing characteristic Building foundations Foundation displacement Frictional resistance Optimization problems Particle image velocimetries Soil displacement fields Ultimate bearing capacity
DOI	10.13225/j.cnki.jccs.2019.0962
收录类别	EI
语种	中文
EI入藏号	20205009602684
EI主题词	Piles
ISSN	02539993
来源库	Compendex
分类代码	408.2 Structural Members and Shapes - 483.1 Soils and Soil Mechanics - 943.3 Special Purpose Instruments - 951 Materials Science
引用统计	无
文献类型	会议论文
条目标识符	https://ir.lut.edu.cn/handle/2XXMBERH/132640
专题	兰州理工大学
作者单位	1.School of Civil Engineering, Lanzhou University of Technology, Lanzhou; 730050, China; 2.School of Civil Engineering, Chongqing Jiaotong University, Chongqing; 400074, China; 3.Department of Military Installations Engineering, Army Logistical University of PLA, Chongqing; 401311, China; 4.Northwest Electric Power Design Institute Co., Ltd., China Power Engineering Consulting Group, Xi'an; 710075, China
第一作者单位	土木工程学院
推荐引用方式 GB/T 7714	Zhang, Jilu,Huang, Xuefeng,Wei, Linhui,et al. Research on visual model test of displacement distribute characteristics and load transfer model of root pile during uplifting[C]:China Coal Society,2020:3435-3445.