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The prediction of active earth pressure was generally implemented under the assumptions of two-dimensional conditions and cohesionless soils. However, in practice, the soils usually display a considerable level of cohesion, and the collapse of retained slopes exhibits a three-dimensional (3D) nature. Considering this fact, this paper intends to predict the 3D active earth pressure in cohesive soils based on the kinematic limit-analysis method and a 3D rotational collapse mechanism. The influence of cracks is considered, including a crack forming before the failure of retained soil masses (open crack) and a crack forming simultaneously with the failure (formation crack). The active earth pressure coefficient is estimated based on the work-energy balance principle. In order to facilitate direct application, several design charts are provided. It is shown that accounting for soil cohesion and 3D effects results in a notable decrease in the active earth pressure, whereas considering the existence of cracks would increase the pressure value. This paper develops the studies on active earth pressure, which considers the presence of cohesion, cracks, and 3D effects together for the first time. The results of this paper can offer references in designs of retaining structures for cohesive slopes. [ABSTRACT FROM AUTHOR]

This study proposes a procedure for predicting the required tensile strength of geosynthetics for three-dimensional (3D) geosynthetic-reinforced soil structures (GRSSs) comprised of cohesive backfills subjected to earthquake loadings. This procedure is undertaken using the kinematic approach of limit analysis together with a pseudo-dynamic approach. The influence of cracks is incorporated into the analysis by using a 3D horn-like failure mechanism that includes a vertical crack to characterize the collapse of GRSSs. Two different forms of cracks are considered: cracks forming prior to the collapse of GRSSs (open cracks) and cracks forming simultaneously with the collapse (formation cracks). Based on the work-energy balance equation, the amount of reinforcements needed to maintain the stability of GRSSs is determined. The results of this paper show that the required reinforcements significantly decrease when soil cohesion and 3D effects are considered, whereas accounting for the existence of cracks and seismic forces has an opposite effect. • The required strength of geosynthetics for seismic GRSSs in cohesive backfills is predicted. • The impact of both open cracks and formation cracks is considered. • A pseudo-dynamic approach is used to account for seismic effects. • The inclusion of 3D effects and soil cohesion leads to a significant reduction in the required amount of reinforcements. • Consideration of seismic effects and existence of cracks has an adverse effect. [ABSTRACT FROM AUTHOR]

Summary: Most of previous analyses on the active earth pressure were performed in two‐dimensional cases using the Mohr‐Coulomb (M‐C) failure function to describe the soil strength. However, all failures of retained slopes indicate a somewhat three‐dimensional (3D) feature, and the M‐C function is found to overestimate the tensile strength of cohesive soil. In this work, a kinematic limit analysis–based approach is developed for computing the 3D active earth pressure resulting from cohesive backfills. The concept of tensile strength cutoff is adopted to implement the reduction or elimination of tensile strength from the strength envelope. An extended 3D horn failure mechanism that is associated with the modified strength envelope is developed to characterize the collapse of retained slopes. The resultant of active earth pressure is evaluated from the work rate balance equation and expressed as an unfactored coefficient. The obtained results indicate that less support provided by the wall is required when allowing the existence of soil cohesion and 3D effects and that eliminating the tensile strength can observably increase the active earth pressure, especially for the backfill with a great level of cohesion. [ABSTRACT FROM AUTHOR]

This work presents a probabilistic analysis of three-dimensional (3D) seismic active earth pressures acting on rigid retaining walls that are designed to support cohesive-frictional soil masses. The analysis is implemented using sparse polynomial chaos expansions (SPCE) to represent the physical model responses. The deterministic evaluation of 3D seismic active earth pressures is conducted with the application of the kinematic approach of limit analysis combined with a pseudo-static method. All of the input parameters are deemed as random variables. After the SPCE metamodels are determined, the method of Monte Carle simulations is applied to perform the probabilistic analysis of 3D seismic active earth pressures. The effects of uncertainty levels and correlation relationships of input parameters are investigated. Several illustrative examples of the reliability-based design of retaining walls are shown. Results indicate that uncertainties in input parameters possess a notable effect on 3D seismic active earth pressures, suggesting the need to investigate the problem from a stochastic perspective. In most cases, the soil cohesion, internal friction angle, and seismic coefficient are found to be three of the parameters that affect the final response the most significantly. It is also indicated that considering 3D effects and soil cohesion has a favorable effect on increasing the stability of retained slopes. [ABSTRACT FROM AUTHOR]

The majority of extant analyses on slope stability assumed a two-dimensional plane-strain condition and/or an intact slope. However, slope failures typically exhibit three-dimensional (3D) characteristics and cracks are commonly present in cohesive slopes. This study develops a framework based on the kinematic limit-analysis method for static and seismic stability evaluation of 3D slopes with cracks. A pseudo-static approach is adopted to represent seismic effects. Two types of cracks are considered: cracks prior to slope failure (open cracks) and cracks forming contemporaneously with slope failure (formation cracks). A 3D horn-like collapse mechanism including a vertical crack is used to represent the slope collapse. A comparison with previous studies is conducted to validate the proposed approach. A series of stability charts is presented for the ease of direct use. Results show that consideration of seismic effects and existence of cracks lead to a significant reduction in slope stability, whereas the inclusion of 3D effects yields a greater safety factor. The influence of cracks becomes more significant for slopes with greater inclination angles and higher levels of soil cohesion. This study considers a more realistic situation, the results of which can serve as a reference tool in the seismic design of slopes. • Static and seismic stability of 3D slopes with cracks is studied. • The influence of both open cracks and formation cracks is included. • Considering seismic effects and existence of cracks will reduce slope stability • The inclusion of 3D effects yields a greater safety factor • The effect of cracks is more significant at greater inclination angles and higher levels of soil cohesion. [ABSTRACT FROM AUTHOR]