Active Earth Pressure against Rigid Retaining Walls Subjected to Confined Cohesionless Soil

Owing to the arching effect caused by stress transfer, the lateral pressure of confined granular material will be influenced by both the wall movement and the confined material width. In this paper, the lateral pressure of confined granular material is studied through the numerical and theoretical analysis. Discrete element-based numerical simulations of different widths are conducted to model the transition of the resultant lateral force. Based on numerical results, an analytical model for estimating the lateral pressure at limit state is proposed by the use of the horizontal slice element method. Moreover, the mobilization models of the granule–wall interface friction angle and the internal friction angle of the granular material are introduced to yield the lateral pressure at nonlimit state. Both numerical and theoretical results indicate that the transition of the lateral pressure can be divided into two stages based on the magnitudes of wall movements, at which the interface friction angle and internal friction angle are fully mobilized. For models with smaller width, the pressure decreases more rapidly in the first stage and eventually reaches smaller lateral pressure at active state, because the vertical stress of the material is transferred to the walls and the stress in the material is redistributed due to the superimposition of the arching effects.

Arching effect on lateral pressure of confined granular material: numerical and theoretical analysis

In this paper, the bearing capacity of strip footings on rock masses has been studied in the seismic case. The stress characteristics or slip line method was used for analysis. The problem was analyzed in the plane strain condition using the Hoek–Brown failure criterion. First, the equilibrium equations along the stress characteristics were obtained and the rock failure criterion was applied. Then, the equations were solved using the finite difference method. A computer code has been provided for analysis. Given the footing and rock parameters, the code can calculate the stress characteristics network and obtain the stress distribution under the footing. The seismic effects have been applied as the horizontal and vertical pseudo-static coefficients. The results of this paper are very close to those of the other studies. The seismic bearing capacity of weightless rock masses can be obtained using the proposed equations and graphs without calculating the whole stress characteristics network.

https://cyberleninka.org/article/n/574375.pdf

Seismic bearing capacity of strip footings on rock masses using the Hoek–Brown failure criterion

Discretization-based kinematical analysis of three-dimensional seismic active earth pressures under nonlinear failure criterion

The hyperbolic function proposed by Abbo–Sloan was employed not only to approach the Mohr–Coulomb criterion but also to express the plastic potential function. A better approximation to the Mohr–Coulomb yield and potential surfaces was achieved by increasing the transition angle and proven to be highly efficient in numerical convergence. When a Gaussian integral point goes into plastic state, two cases on yield stress adjustments were introduced. They may avoid solving the second derivative of the plastic potential function and the inverse matrix compared with the existing subroutine. Based on the above approaches, a fully implicit backward Euler integral regression algorithm was adopted. The two- and three-dimensional user subroutines which can consider the associated or non-associated flow rule were developed on the platform of the finite element program—ABAQUS. To verify the reliability of these two subroutines, firstly, the numerical simulations of the indoor conventional triaxial compression and uniaxial tensile tests were performed, and their results were compared with those of the embedded Mohr–Coulomb model and the analytical approach. Then the main influential factors including the associated or non-associated flow rule, the judgment criteria of slope failure, and the tensile strength of soil were analyzed, and the application of the two-dimensional subroutine in the stability analysis of a typical soil slope was discussed in detail through comparisons with the embedded model and the limit analysis method, which shows that this subroutine is more applicable and reliable than the latter two.

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Numerical implementation of a modified Mohr–Coulomb model and its application in slope stability analysis

The slip-line method is commonly used to solve the limit earth pressure on retaining walls, but to date there are still a number of problems that have not yet been solved. Based on limit equilibrium theory, the backfill is considered to be an ideal elastic-plastic material, which obeys the Mohr–Coulomb yield criterion, and is assumed to be an ideal continuous medium that is isotropic, homogeneous and incompressible (or non-expansive). Various factors of influence are considered in the calculation model. An elastic overburden is proposed as a replacement for traditional tension cracks. A new concept – stress singularity – and its stress boundary conditions are introduced, and a statically determinate and solvable mathematical model for the limit equilibrium problem is established without considering the stress–strain relationship of the soil. The slip-line stress field in the plastic zone of the backfill is solved by using the slip-line method, following which the active earth pressure on retaining walls a...

M.X. Peng

Papers

Slip-line solution to active earth pressure on retaining walls