TITLE:
Study on Optimization of Design Parameters for Precast Pipe Pile Treatment of Soft Soil Subgrade on the Jianghan Plain
AUTHORS:
Yajun Wang, Yifeng Li, Jinzhou Chen
KEYWORDS:
Expressway, Weak Soil Roadbed, Prefabricated Tubular Pile, Numerical Simulation, Settlement Calculation
JOURNAL NAME:
Open Journal of Civil Engineering,
Vol.13 No.3,
September
22,
2023
ABSTRACT: The soft soil in the Jianghan Plain is characterized by a high water
content, liquid limit, sensitivity, porosity ratio, and organic matter content
and low strength and is commonly known as “five highs and one low” soft soil.
Thus, the construction of expressways in this area is likely to cause subgrade
settlement. The manuscript investigated the influence of the design parameters
of precast pipe piles on the soft ground treatment in the Jianghan Plain based
on the case of the soft soil subgrade project of the Xiaogan south section of
the Wuhan city ring expressway, China. Midas GTS NX 2019 finite element
software was used to analyse the settlement pattern of the subgrade under the
variations in pile length, pile spacing and pile diameter. The results show
that precast pipe piles are effective in reducing the settlement of soft soil
subgrades with a high compressibility and water content; the soft foundation
settlement decreases with increasing pile length and pile diameter and
decreasing pile spacing. As the pile tip is embedded in the bearing stratum,
the settlement of the soft foundation is greatly affected by the variations in
pile length and pile spacing while slightly influenced by the variation in pile
diameter; in combination with the curve fitting obtained from the real-time
monitoring data, the analysis concludes that the soft foundation treatment plan
with a pile length of 15 m, pile spacing of 1.2 m to 1.5 m and pile diameter of
0.6 m can better contain the soft soil subgrade settlement in this section.