In performance-based design, it is crucial to understand deformation characteristics of geocell layers in soil under footing loads. To explore this, a series of laboratory loading tests were carried out to investigate the influence of varying parameters on the strain levels within the geocell layer in a sandy soil under axial strip footing loading. The results were analyzed in terms of maximum strain levels, strain variation along the geocell layer and the correlation between horizontal and vertical strains. In this study, the maximum observed strain levels for geocellreinforced strip footing systems reached 2.3 % for horizontal (tensile) strain and 1.4 % for vertical (compressive) strain. Furthermore, most strain levels were concentrated within a distance of 1.5 times the footing width from the axis of strip footing. In geocell-reinforced footing systems, the interaction between horizontal and vertical strains becomes a key factor, with the ratio of horizontal to vertical cell wall strains ranging approximately from 1 to 2.5. The outcomes of this study are expected to contribute to the practical applications of geocell-reinforced footing systems.

Tiered geosynthetic-reinforced soil (GRS) walls in transportation engineering are often applied in high-retaining soil structures and are typically subjected to traffic cyclic loading. However, there has been limited research on the dynamic performance of tiered GRS walls. Three reduced-scale model walls were conducted to investigate the dynamic performances of two-tiered GRS walls with different strip footing locations (d/H) under cyclic loading. The test results demonstrated that cyclic loading parameters such as average load P0 and load amplitude PA have a significant effect on the dynamic performance of the tiered walls. However, the change in loading frequency f has a minor effect on the settlement and lateral deformation when the GRS wall reaches a relatively stable state. Under the same P0 and PA, the measured maximum additional vertical stress Delta sigma v,max decreases with the increase of frequency f, whereas minimum additional vertical stress Delta sigma v,min increases. The stress distribution profile along the horizontal direction at the lower-tier wall crest is related to the strip footing location. The bearing capacity of the GRS wall increases and then decreases with increasing d/H within the reinforced zone of the upper-tier wall. The variation magnitude and distribution profile of the lateral deformations are influenced by the d/H and cyclic loading levels, especially for the upper-tier wall. When the strip footing remains in the reinforced zone of the upper-tier wall, potential slip surfaces go deeper as it moves away from the wall face. Finally, a power relationship between the calculated factor of safety and the maximum lateral deformation monitored from model tests for the two-tiered GRS walls under cyclic loading is established.

Tunneling-induced horizontal strains for buildings with discontinuous foundations are notable and may pose significant risks to the integrity of nearby structures. This paper presents results from a series of numerical models investigating the response of framed buildings on separated footings to tunnel construction in sand. The study examines a two-story, elastic frame with varying building transverse width, eccentricity, and first story height, subjected to tunneling-induced displacements; footing embedment depth and tunnel cover depth are also varied. Results show that tunneling-induced horizontal displacements for separated footings are significant, with greater footing horizontal displacements occurring at deeper footing embedment depths. Building width and eccentricity also influence soil-footing interaction, particularly in determining the values of footing displacements and the distribution of horizontal strains. An increase in footing embedment depth slightly increases shear distortion but significantly increases horizontal strains. The presented modification factors for angular distortion and horizontal strains align well with empirical envelopes, with the horizontal strain modification factor being sensitive to the relative soil-footing stiffness. This research highlights the importance of considering horizontal strains and realistic foundation embedment depth in the damage assessment for buildings with discontinuous foundations due to tunnel construction.

The aim of the present study is to assess the impact of rotational anisotropy on the undrained bearing capacity of a surface strip footing over an unlined circular tunnel on spatially variable clayey soil. The finite-difference method (FDM) is utilised to perform both deterministic and stochastic analyses. The Monte Carlo simulation approach is used to estimate the mean stochastic bearing capacity factor (mu Npro) and probability of failure (pf) of the entire system. The responses are evaluated for different geometric and spatially variable parameters and the strata rotation angle (beta). The failure patterns and the required factor of safety (FSr) corresponding to a specific probability of failure (e.g. pft = 0.01%) are determined for various parameters. The results obtained for the rotational anisotropy (beta$\ne \;$not equal 0) are observed to be significantly different from those for horizontal anisotropic structure (beta = 0), and considering only the horizontal anisotropic structure may lead to the overestimation or underestimation of the response of the structure.

This paper presents a comprehensive assessment of the accuracy of high-frequency (HF) earth meters in measuring the tower-footing ground resistance of transmission line structures, combining simulation and experimental results. The findings demonstrate that HF earth meters reliably estimate the harmonic grounding impedance (R25kHz) at their operating frequency, typically 25 kHz, for a wide range of soil resistivities and typical span lengths. For the analyzed tower geometries, the simulations indicate that accurate measurements are obtained for adjacent span lengths of approximately 300 m and 400 m, corresponding to configurations with one and two shield wires, respectively. Acceptable errors below 10% are observed for span lengths exceeding 200 m and 300 m under the same conditions. While the measured R25kHz does not directly represent the resistance at the industrial frequency, it provides a meaningful measure of the grounding system's impedance, enabling condition monitoring and the evaluation of seasonal or event-related impacts, such as damage after outages. Furthermore, the industrial frequency resistance can be estimated through an inversion process using an electromagnetic model and knowing the geometry of the grounding electrodes. Overall, the results suggest that HF earth meters, when correctly applied with the fall-of-potential method, offer a reliable means to assess the grounding response of high-voltage transmission line structures in most practical scenarios.

Soil-water characteristics, which vary with hydrological events such as rainfall, significantly influence soil strength properties. These properties are crucial determinants of the bearing capacity of foundations. Moreover, shear strength characteristics of soils are inherently spatially variable, and considering them as homogeneous parameters can result in unreliable design. This paper presents a probabilistic study of the two-dimensional bearing capacity of a strip footing on spatially random, unsaturated fine-grained soil using Monte Carlo simulation. The study employs the hydro-mechanical random finite difference method through MATLAB programming along with FLAC2D software. The undrained shear strength under saturated conditions is modelled as random fields using a log-normal distribution. The generated random values are then made depth-dependent by correlating them with matric suction. Initially, matric suction is assumed to be under a hydrostatic condition and decreases linearly with depth to zero at the groundwater level. Afterward, unsaturated soil is subjected to rainfall with different durations, resulting in the non-linear distribution of matric suction and, consequently, the mean value of undrained shear strength in depth. The results showed that rainfall infiltration impacts the strength characteristics of near-surface heterogeneous strata, leading to significant effects on the bearing capacity and failure mechanism of footing.

This research presents a new mathematical framework for the optimal design of elliptical isolated footings under vertical load and two orthogonal moments. The suggested method considers the spatial variation of contact pressure between the footing and the supporting soil, facilitating an accurate representation of structural requirements. New formulations for bending moment, unidirectional shear, and punching shear are generated using volume integration, accurately representing the complex stress distribution beneath elliptical foundations. Lagrange multipliers are utilized to identify the crucial points of maximum and minimum contact stresses for elliptical and circular footing shapes. A thorough numerical analysis illustrates the benefits of the suggested strategy by contrasting its results with those of a conventional design methodology. The findings demonstrate that the newly created model produces more cost-effective designs while maintaining structural integrity and performance, underscoring its potential as a significant asset in engineering practice. A MATLAB code for design using new formulas is programmed and results obtained to those from literature and were more efficient and economic.

Rocking isolation is an effective method for reducing structural damage during earthquakes and aligns with a seismic design approach that aims to minimize damage to bridges. The seismic responses of rocking structures are significantly influenced by the soil-structure interaction and the soil characteristics. In this research, a shaking table test was conducted on a single-pier rigid-frame bridge model with an uplifting footing, considering soil-structure interaction. This test was used to validate a finite element model (FEM) developed using ABAQUS software. Subsequently, the seismic responses of the rigid- frame bridge with a pile foundation capable of rocking at the pier base were analyzed in detail. Four soil types, including silt, silt clay, sand, and clay, were examined, and two foundation types were considered: a fixed pile foundation and a rocking pile foundation. The results indicate that uplifting the footing can reduce the deck's acceleration and the pier's bending moment, while increasing the bridge's displacement, compared to a bridge with a fixed pile foundation.

The T-shaped strip footing is a good choice for building foundations because it effectively resists overturning forces and accommodates eccentric loading. The footing's embedded within the soil enhances its capacity to counteract the forces generated by eccentric loading, providing additional stability and support. This study presents a couple of finite element limit analysis (FELA) and regression machine learning models in predicting the bearing capacity of eccentrically loaded T-shaped footings on anisotropic clays. A numerical simulation of T-shaped strip footings in anisotropic clay under eccentric loading is performed using a FELA software, namely OptumG2. At the same time, the regression soft computing models employed four techniques, including the genetic programming (GP), age-layered population structure-genetic algorithm (ALPS-GA), offspring selection genetic algorithm (OSGA), and grammatical evolution (GE) models. The AUS yield criterion is utilized to govern the soil properties, while the footing is modeled as a rigid material. By emphasizing the stability of the surrounding soil, this study neglects the failure of the footing itself since the footing is assumed to be very rigid. Parametric analyses are conducted using a dimensionless approach. The influences of eccentricity (e/B), the insertion length ratio (D/B), the anisotropic strength ratio (re), and the adhesion factor (alpha) on the bearing capacity factor (N) are investigated. The impact of these dimensionless parameters on the shear dissipation of the model to monitor the failure pattern is discussed. The current results are compared with prior solutions, showing consistency. Moreover, predictive regression machine learning techniques (GP, ALPS-GA, OSGA, and GE models) are applied to develop empirical equations for N estimation, with the proposed OSGA model demonstrating superior performance, achieving coefficients of determination (R2) of 0.985 and 0.984 for the training and testing sets, respectively.

Numerical modelling of laterally loaded piles requires a robust pile-soil interface model. The conventional Coulomb friction model has limitations when predicting the soil-structure interaction at shallow depths for battered mini piles (BMPs) in cohesive (fine-grained) soils. This paper proposes an efficient pile-soil interface model to simulate laterally loaded BMPs in cohesive soils using three-dimensional finite element models (FEM). BMP systems have been commonly used to support lateral load-dominated lightweight superstructures. They are hybrid foundations with BMPs oriented at different inclinations and directions, mimicking tree root systems. FEM results indicate that the Coulomb model is unsuitable for simulating the pile-soil interface at shallow depth due to underprediction of shear resistance. The proposed interface model comprising a surface-to-surface cohesive damage interface with friction captures the lateral performance of BMPs accurately. The proposed model was implemented for a range of pile and soil properties to verify its suitability in understanding the behaviour of BMPs. The ultimate lateral capacity of BMPs increases with penetration length up to 1.5 m. While an increase in diameter and undrained shear strength increases the capacity, the lateral load eccentricity negatively impacts it. Interaction diagrams are developed to serve engineers estimate the ultimate lateral capacity of BMPs.