XIAO Chengzhi,SI Yu,WANG Zihan,et al.Test Study on Axial Mechanical Properties of Grouted Micro⁃steel⁃pipe⁃piles[J].Journal of Disaster Prevention and Mitigation Engineering,2021,41(06):1167-1176.
XIAO Chengzhi,SI Yu,WANG Zihan,et al.Test Study on Axial Mechanical Properties of Grouted Micro⁃steel⁃pipe⁃piles[J].Journal of Disaster Prevention and Mitigation Engineering,2021,41(06):1167-1176. DOI: 10.13409/j.cnki.jdpme.201907056.
Test Study on Axial Mechanical Properties of Grouted Micro⁃steel⁃pipe⁃piles
Studies on mechanical and deformation performance of grouted micro-steel-pipe-piles (MSPP) in pile engineering are relatively rare. In this paper, a series of tests were carried out to investigate the effect of the parameters, such as diameter
d
and wall thickness
t
of steel pipe, the length of pile specimen
H
, the water-cement ratio, and the layout mode of holes in steel pipes, on axial bearing capacity, deformation and failure mode of MSPP. The tests results showed that the diameter and the wall thickness of steel pipe play dominant roles in enhancing axial bearing capacity of MSPP. With the increase of diameter and wall thickness of steel pipe, the ultimate axial load of MSPP tends to increase linearly, and the failure mode of MSPP shifts from brittle failure to ductile fracture. Increasing the length of MSPP specimen or improving the water-cement ratio results in a decrease of axial ultimate bearing capacity; when the diameter ratio of steel pipe to MSPP,
d
/
D
, increases and falls in the range of 0.59 to 0.72, the length of MSPP specimen, the water-cement ratio and the layout of holes do not significantly affect the axial ultimate bearing capacity of MSPP. Furthermore, on the basis of comprehensive consideration on axial load characteristics and mechanical behavior and strain of steel pipe, a reasonable diameter ratio range of steel pipe to MSPP, 0.59≤
d
/
D
≤0.72, is presented herein, and an empirical expression on calculating the axial bearing capacity of grouted MSPP is put forth as well. The analytical results in this paper will be helpful in guiding design of MSPP in practical projects.
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references
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