scholarly journals Semi-analytical solutions to consolidation for unsaturated soils by vertical drains under arbitrary time-dependent loading

Author(s):  
Aifang Qin ◽  
Lianghua Jiang ◽  
Tianyi Li ◽  
Weifang Xu
2021 ◽  
Vol 147 (9) ◽  
pp. 04021055
Author(s):  
Deqiang Chen ◽  
Pengpeng Ni ◽  
Xinlei Zhang ◽  
Zheng Chen ◽  
Guoxiong Mei ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Pyol Kim ◽  
Hyong-Sik Kim ◽  
Yong-Gun Kim ◽  
Chung-Hyok Paek ◽  
Song-Nam Oh ◽  
...  

This paper presents analytical solutions for nonlinear radial consolidation of soft soil with vertical drains under various cyclic loadings. By considering the nonlinear variations of compressibility and permeability expressed by the logarithm relations (e−log σ′ and e−log kh), the governing equation for nonlinear radial consolidation of the soil under equal strain and time-dependent loading is established. The analytical solutions are derived for nonlinear radial consolidation under haversine cyclic loading, trapezoidal cyclic loading, rectangular cyclic loading, and triangular cyclic loading. The presented solution is verified through the degeneration into the existing solutions for nonlinear radial consolidation under constant and ramp loadings, which shows the solution proposed in this paper is more general for nonlinear radial consolidation under time-dependent loading. The nonlinear radial consolidation behavior of the soil with vertical drains subjected to various cyclic loadings is investigated using the solutions developed. The proposed solutions can be effectively utilized in the analysis of nonlinear radial consolidation under various cyclic loadings.


2001 ◽  
Vol 37 (4) ◽  
pp. 1091-1093 ◽  
Author(s):  
Jiann-Mou Chen ◽  
Yih-Chi Tan ◽  
Chu-Hui Chen ◽  
J.-Y. Parlange

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Feng Zhou ◽  
Zheng Chen ◽  
Xudong Wang

Developing an analytical solution for the consolidation of unsaturated soils remains a challenging task due to the complexity of coupled governing equations for air and water phases. This paper presents an equal-strain model for the radial consolidation of unsaturated soils by vertical drains, and the effect of drain resistance is also considered. Simplified governing equations are established, and an analytical solution to calculate the excess pore-air and pore-water pressures is derived by using the methods of matrix analysis and eigenfunction expansion. The average degrees of consolidation for air and water phases and the ground surface settlement are also given. The solutions of the equal-strain model are verified by comparing the proposed free-strain model with the equal-strain model, and reasonably good agreement is obtained. Moreover, parametric studies regarding the drain resistance effect are graphically presented.


Author(s):  
M. Fakoor-Pakdaman ◽  
M. Andisheh-Tadbir ◽  
Majid Bahrami

A new all-time model is developed to predict transient laminar forced convection heat transfer inside a circular tube under arbitrary time-dependent heat flux. Slug flow condition is assumed for the velocity profile inside the tube. The solution to the time-dependent energy equation for a step heat flux boundary condition is generalized for arbitrary time variations in surface heat flux using a Duhamel’s integral technique. A cyclic time-dependent heat flux is considered and new compact closed-form relationships are proposed to predict: i) fluid temperature distribution inside the tube ii) fluid bulk temperature and iii) the Nusselt number. A new definition, cyclic fully-developed Nusselt number, is introduced and it is shown that in the thermally fully-developed region the Nusselt number is not a function of axial location, but it varies with time and the angular frequency of the imposed heat flux. Optimum conditions are found which maximize the heat transfer rate of the unsteady laminar forced-convective tube flow. We also performed an independent numerical simulation using ANSYS to validate the present analytical model. The comparison between the numerical and the present analytical model shows great agreement; a maximum relative difference less than 5.3%.


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