A new simplified method is proposed to compute the active earth pressure acting on the backface of a rigid retaining wall undergoing horizontal translation. The effect of soil arching for cohesive backfill soil and friction mobilized along the wall–soil interface was considered. Analytical expressions to determine the slip surface angle and the coefficient of active earth pressure were obtained using the limit-equilibrium approach. These expressions were used for the horizontal flat-element method to obtain theoretical formulas for the active earth pressure, active thrust, and its point of application. Additionally, an implicit solution was derived for the depth of the tension crack in the backfill. A parametric study was undertaken to assess the effects of cohesion, unit weight, friction angle, surcharge pressure, and wall–soil friction angle on the active earth pressure, as well as the effects of the friction angle of backfill soil and wall–soil friction angle on the slip surface angle. The res...

In this study, a novel analytical approach is proposed to calculate the passive earth pressure against a rigid retaining wall subjected to the translation mode. Effects of arching in cohesive backfill soils as well as friction mobilized along the wall–soil interface are considered. Analytical expressions of the earth pressure, passive resistance, and its height of application on the backface of the retaining wall were derived based on static equilibrium of forces under passive conditions acting on the failure wedge. A parametric study was undertaken to assess effects of internal friction angle of backfill, wall–soil interface friction angle, surcharge pressure, cohesion, unit weight, and inclination angle of the slip surface on the active earth pressure as well as on the slip-surface angle. The results of the proposed method were then verified against the existing test data as well as the predictions by Coulomb theory and Rankine theory. The results show that the proposed method yields satisfactor...

In this paper, a simple and efficient fractal-based approach is presented for capturing the effects of initial void ratio on the soil-water characteristic curve (SWCC) in a deformable unsaturated soil. In terms of testing results, the SWCCs (expressed by gravimetric water content) of the unsaturated soils at different initial void ratios were found to be mainly controlled by the air-entry value (Ψ_a), while the fractal dimension (D) could be assumed to be constant. As a result, in contrast to the complexity of existing models, a simple and efficient model with only two parameters (i.e., D and Ψ_a) was established for predicting the SWCC considering the effects of initial void ratio. The procedure for determining the model parameters with clear physical meaning were then elaborated. The applicability and accuracy of the proposed model were well demonstrated by comparing its predictions with four sets of independent experimental data from the tests conducted in current work, as well as the literature on a wide range of soils, including Wuhan Clay, Hefei and Guangxi expansive soil, Saskatchewan silt, and loess. Good agreements were obtained between the experimental data and the model predictions in all of the cases considered.

Rheological characteristics are one of most important properties needed to be considered in the design and construction for the long-term stability and serviceability of underground structures in the rock mass. To date, although extensive studies on the rheological properties of rocks are available in the literature, most of the existing studies reported the strain-time data for the axial deformation through the compression rheological method and did not mention the lateral deformation, and mainly focused on the soft rocks at shallow depth. Thus, very limited attention has been paid to the rheological properties of deep and hard rock, neglecting the effects of structural anisotropy on the rheological properties. This paper presents a comprehensive, in-depth study of the rheological behaviors of super-deep hard rock, considering the effects of structural anisotropy by using the uniaxial and biaxial creep tests. The results revealed that significant creep behavior can be observed in the hard rock sp...

This paper proposes an efficient hybrid approach for analysis of the responses of piled-raft foundations subjected to coupled loads (combination of vertical loads, horizontal loads, and moments) in layered soils. The proposed method comprehensively accounts for pile–pile, pile–soil surface, soil surface–pile, and soil surface–soil surface interactions. Moreover, to capture the influence of embedment and active/passive effects of piles, a modified Vesic’s subgrade modulus for embedded piles and passive piles was adopted. To avoid a large number of time-consuming integration processes, the shear displacement method and elastic foundation beam method were employed to calculate the vertical and horizontal responses of a single pile, respectively, and the results were then extended for the pile group. The results calculated with the proposed method for piled-raft foundations in layered soils were found to have good agreement with those obtained from the more rigorous finite-element methods (FEMs) and ...