Analytical solution for consolidation of saturated soft clay under vacuum preloading with non-sand drainage system considering nonlinear drain resistance
NI Rui-si, XIAO Shi-guo, WU Bing, et al. Analytical solution for consolidation of saturated soft clay under vacuum preloading with non-sand drainage system considering nonlinear drain resistance[J]. 2025, 46(7): 2160-2178.
NI Rui-si, XIAO Shi-guo, WU Bing, et al. Analytical solution for consolidation of saturated soft clay under vacuum preloading with non-sand drainage system considering nonlinear drain resistance[J]. 2025, 46(7): 2160-2178.DOI: 10.16285/j.rsm.2024.1237.
Based on the basic characteristics of the sand-free air-boosted vacuum preloading
a radial seepage calculation unit model centered on the booster pipe
which is a non-ideal well
is established
taking into account the spatiotemporal nonlinear characteristics of the well resistance of drainage plates and the relationship between the booster load and its pipe length. The nonhomogeneous partial differential control equations are consequently derived. According to the Sturm-Liouville eigentheory
the analytical solution to the excessive pore water pressure is obtained using the eigenfunction expansion method. Further
analytical expressions for calculating the excessive pore water pressure and the average consolidation degree of the foundation are provided under three typical practical pressurization modes
including constant pressurization loading
constant pressurization loading in the later stage
and intermittent pressurization in the later stage
respectively. Some examples show that the excessive pore water pressure increases as the length of the pressurized pipe increases
and always shows a nonlinear distribution that gradually increases with depth. After the pressurization is initiated
the excessive pore water pressure increases instantaneously
with a more pronounced increase in the middle and lower parts of the foundation
and subsequently
its dissipation rate also increases. The total pressurization duration has a significant impact on the consolidation degree of the foundation. When the pressurization loads are 20 kPa and 40 kPa
the consolidation degrees increase by approximately 8% and 9%
respectively
for a total pressurization duration of 100 d compared to 50 d.