Numerical Analysis Method considering Coupled Effects of THMC Multifields on Unsaturated Expansive Soil Subgrade Treated with Lime

Abstract

The response model subjected to coupled effect of thermo-hydro-mechano-chemical (THMC) was built in the context of basic theories in the polyporous polyphasic medium mechanics, the mixture theory in the continuum mechanics, and the thermodynamic theories. The finite element discretization of the response model was implemented based on the Galerkin method. The processes of salt leaching and accumulating were analyzed in the numerical results. The results among the numerical results and measured results were compared and discussed. Finally, the solutes migration rule of the soil subjected to the atmosphere eluviations was revealed, and the reasonableness of the coupling model and the finite element method was proved. The agreement between the numerical and the measured results was good, which indicates that the THMC model and finite element program were useful in solving the coupling problems of unsaturated soil. Moreover, the salt dissolution process has a larger effect on the salt movement compared to that of the salt accumulation process. Comparing with the salt leaching effect caused by rainfall, the salt accumulation effect caused by evaporation was smaller.

The Conformal Finite-Difference Time-Domain Simulation of GPR Wave Propagation in Complex Geoelectric Structures

“…Through the analysis of computed geoelectrical echo signals, the propagation of GPR signals can be further understood. The method of finite-difference time-domain (FDTD) analysis is the most widely used numerical simulation technique of GPR [1], which has the characteristics of directness and generality, and electromagnetic parameters of the target are reflected in the electromagnetic field of every grid [2]. In order to produce numerical simulation of GPR, mesh generations of complex geoelectric structures were constructed, the extent of which will directly affect the computing accuracy of the calculated results [3].…”

Experimental Study on the Evaluation in Thermal-Hydraulic-Mechanical-Chemical Properties of Cement-Stabilized Clay

“…In view of the fact that the application of coupling processes plays a crucial role in solving practical engineering problems, some research efforts were performed to provide a deeper understanding of the coupled processes in the treated soil. Experimental studies and numerical modeling were performed on to have a deeper understanding on the MC 51,52 , HM 53,54 , THM 49 , HMC 41,55 , THCM 56 behavior of treat soil. Although the aforementioned studies have made a fundamental understanding of the THMC behavior of the treated soil, there are no comprehensive investigations that have tackled the THMC behaviour of the cementclay.…”