Numerical modeling of pile penetration in silica sands considering the effect of grain breakage

Summary To solve large deformation geotechnical problems, a novel strain‐smoothed particle finite element method (SPFEM) is proposed that incorporates a simple and effective edge‐based strain smoothing method within the framework of original PFEM. Compared with the original PFEM, the proposed novel SPFEM can solve the volumetric locking problem like previously developed node‐based smoothed PFEM when lower‐order triangular element is used. Compared with the node‐based smoothed PFEM known as “overly soft” or underestimation property, the proposed SPFEM offers super‐convergent and very accurate solutions due to the implementation of edge‐based strain smoothing method. To guarantee the computational stability, the proposed SPFEM uses an explicit time integration scheme and adopts an adaptive updating time step. Performance of the proposed SPFEM for geotechnical problems is first examined by four benchmark numerical examples: (a) bar vibrations, (b) large settlement of strip footing, (c) collapse of aluminium bars column, and (d) failure of a homogeneous soil slope. Finally, the progressive failure of slope of sensitive clay is simulated using the proposed SPFEM to show its outstanding performance in solving large deformation geotechnical problems. All results demonstrate that the novel SPFEM is a powerful and easily extensible numerical method for analysing large deformation problems in geotechnical engineering.

Section: Introductionmentioning

confidence: 99%

An edge‐based strain smoothing particle finite element method for large deformation problems in geotechnical engineering

Jin

Yuan

Yin

et al. 2020

“…Reliable predictions depend heavily on plausible constitutive models with reasonable parameters in geotechnical engineering . To achieve this purpose, many constitutive models have been proposed for soils .…”

Section: Introductionmentioning

confidence: 99%

“…Reliable predictions depend heavily on plausible constitutive models with reasonable parameters in geotechnical engineering. [1][2][3][4][5][6][7] To achieve this purpose, many constitutive models have been proposed for soils. [8][9][10][11] However, different constitutive models render dissimilar results in the process of numerical simulations, prompting variations in engineering decisions that affect the levels of safety, economy, and risk in construction.…”

Section: Introductionmentioning

confidence: 99%

Bayesian model selection for sand with generalization ability evaluation

Jin

Yin

Zhou

et al. 2019

Summary Current studies have focused on selecting constitutive models using optimization methods or selecting simple formulas or models using Bayesian methods. In contrast, this paper deals with the challenge to propose an effective Bayesian‐based selection method for advanced soil models accounting for the soil uncertainty. Four representative critical state‐based advanced sand models are chosen as database of constitutive model. Triaxial tests on Hostun sand are selected as training and testing data. The Bayesian method is enhanced based on transitional Markov chain Monte Carlo method, whereby the generalization ability for each model is simultaneously evaluated, for the model selection. The most plausible/suitable model in terms of predictive ability, generalization ability, and model complexity is selected using training data. The performance of the method is then validated by testing data. Finally, a series of drained triaxial tests on Karlsruhe sand is used for further evaluating the performance.

“…However, this type of conditioning agent is not cost‐friendly because of the requirement for the large‐scale equipment to apply . Water‐soluble polymer, such as carboxy methyl cellulose (CMC), can be employed to increase of soil viscosity and to form plastic flow of soil . But it is only suitable for cohesionless soils.…”

Section: Introductionmentioning

confidence: 99%

“…23 Water-soluble polymer, such as carboxy methyl cellulose (CMC), can be employed to increase of soil viscosity and to form plastic flow of soil. [24][25][26] But it is only suitable for cohesionless soils. Super absorbent resin (SAR) is employed for preventing water inflow by changing soils with high water content to gelation conditions.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of foam conditioning effect on groundwater inflow at tunnel cutting face

Liu

Shen

Zhou

et al. 2018

Summary This paper presents an analytical evaluation on the influence of foam conditioning on groundwater inflow at shield tunnel cutting face by the force‐equilibrium principle. Three key variables are highlighted, namely, the maximum foam infiltration distance, the critical infiltration distance, and the hydraulic conductivity of foam‐conditioned soil or rock fissure. To capture the variation of water level induced by foam injection, a dynamic water‐level equation is considered in the force‐equilibrium principle. The proposed analytical equations are employed to analyze a water inflow case during shield tunneling in a weathered mylonite fault. The results indicate that the hydraulic conductivity of foam‐conditioned mylonite and the infiltration distance decrease with an increase of shear stress of foam fluid. A three‐dimensional finite element model is employed to validate the analytical solutions. The comparison between the observed and calculated results confirms that the proposed method can predict groundwater inflow in foam‐conditioned soils.