scholarly journals Numerical Analysis of Unsaturated Soil Slopes under Rainfall Infiltration Based on the Modified Glasgow Coupled Model

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Guoqing Cai ◽  
Mengzi Li ◽  
Bowen Han ◽  
Kenan Di ◽  
Qianqian Liu ◽  
...  
Keyword(s):  
Unsaturated Soil ◽  
Fluid Velocity ◽  
Coupled Model ◽  
Rainfall Infiltration ◽  
Secondary Development ◽  
Infiltration Process ◽  
Integration Algorithm ◽  
Soil Slopes ◽  
Implicit Integration Algorithm ◽  
Numerical Program

An ABAQUS UMAT subroutine was used for the secondary development of the established coupled hydromechanical constitutive model of unsaturated soil considering the effect of the microscopic pore structure. Combined with Euler’s backward implicit integration algorithm, a numerical program was established for simulating the proposed model. The developed numerical program was used to simulate the rainfall infiltration process of an actual slope engineering example, and the effects of rainfall intensity and rainfall duration on the pore pressure, fluid velocity, and displacement of the unsaturated soil slope were analyzed. The results show that the developed numerical program can reasonably analyze the changes in the seepage field and displacement field of unsaturated soil slopes under rainfall infiltration.

scholarly journals Numerical Implementation of a Hydro-Mechanical Coupling Constitutive Model for Unsaturated Soil Considering the Effect of Micro-Pore Structure

2021 ◽  
Vol 11 (12) ◽  
pp. 5368
Author(s):  
Guoqing Cai ◽  
Bowen Han ◽  
Mengzi Li ◽  
Kenan Di ◽  
Yi Liu ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Mechanical Behavior ◽  
Pore Structure ◽  
Unsaturated Soil ◽  
Fortran Program ◽  
Numerical Implementation ◽  
Numerical Application ◽  
Integration Algorithm ◽  
Mechanical Coupling ◽  
Numerical Program

An unsaturated soil constitutive model considering the influence of microscopic pore structure can more accurately describe the hydraulic–mechanical behavior of unsaturated soil, but its numerical implementation is more complicated. Based on the fully implicit Euler backward integration algorithm, the ABAQUS software is used to develop the established hydro-mechanical coupling constitutive model for unsaturated soil, considering the influence of micro-pore structure, and a new User-defined Material Mechanical Behavior (UMAT) subroutine is established to realize the numerical application of the proposed model. The developed numerical program is used to simulate the drying/wetting cycle process of the standard triaxial specimen. The simulation results are basically consistent with those calculated by the Fortran program, which verifies the rationality of the developed numerical program.

The Research of Slope Stability Based on Unsaturated Soil Theory

2014 ◽  
Vol 937 ◽  
pp. 590-593
Author(s):  
Chang Qing Shao ◽  
Nan Zhang ◽  
Feng Lan Lv
Keyword(s):  
Unsaturated Soil ◽  
Evaluation Methods ◽  
Rainfall Infiltration ◽  
Stability Factor ◽  
Analysis Method ◽  
Infiltration Process ◽  
Strong Activity ◽  
The Matrix ◽  
Matrix Suction ◽  
The Stability

With the deep landslide induced by rainfall or more in practice, the existing evaluation methods are not suitable for to explain this kind of landslide during rainfall, which is the phenomenon of strong activity. This paper tries to improve existing methods for analyzing the stability of the landslide, the article set up to consider soil stability analysis method of the matrix suction side article discusses rainfall infiltration process middle side matrix suction changes impacting on the stability of the landslide, the preliminary discussion on the effect of rainfall on deep landslide are studied. Considering soil of the side of the evaluation methods of matrix suction jettisoned traditional saturated unsaturated soil mechanics analysis method, it can well reflect the process of rainfall infiltration, the matrix suction decreases, and the inter-atomic forces, stability factor to reduce the process, providing a train of thought for landslides evaluation.

Application of a multilaminate model to simulate the undrained response of structured clay to shield tunnelling

2008 ◽  
Vol 45 (1) ◽  
pp. 14-28 ◽  
Author(s):  
H. Kien Dang ◽  
Mohamed A. Meguid
Keyword(s):  
Field Measurements ◽  
Soil Parameters ◽  
Explicit Integration ◽  
Integration Algorithm ◽  
Finite Element Program ◽  
Surface Displacements ◽  
Implicit Integration Algorithm ◽  
Element Program ◽  
Shield Tunnelling ◽  
Structured Clay

A constitutive model based on the multilaminate framework has been implemented into a finite element program to investigate the effect of soil structure on the ground response to tunnelling. The model takes into account the elastic unloading–reloading, inherent and induced anisotropy, destructuration, and bonding effects. The model is successfully calibrated and used to investigate the undrained response of structured sensitive clay in the construction of the Gatineau tunnel in Gatineau, Quebec. Numerical results were compared to the field measurements taken during tunnel construction. To improve the performance of the numerical model, an implicit integration algorithm is implemented and proven to be very effective when coupled with the multilaminate framework as compared to the conventional explicit integration methods. The effect of different soil parameters including bonding and anisotropy on the tunnelling induced displacements and lining stresses is also examined using a comprehensive parametric study. The results indicated that soil bonding and anisotropy have significant effects on the shape of the settlement trough as well as the magnitudes of surface displacements and lining stresses induced by tunnelling.

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