Soil creep is a slow type of mass movement that, despite its low velocity, can significantly influence slope stability and landscape evolution over time. Understanding its mechanisms and spatial variability is essential for assessing slope stability. However, obtaining high-quality long-term data on creep activity remains a challenge. Dendrogeomorphic methods offer a promising approach to reconstruct past creep movements, but their application to shallow creep processes still requires further refinement. Therefore, this research undertakes a dendrogeomorphic analysis of shallow creep movements on flysch rock slopes, utilizing tree-ring eccentricity as an indicator of this geomorphic process. A total of 136 increment cores from 68 Norway spruce (Picea abies (L.) H. Karst.) trees were analysed, revealing the spatio-temporal dynamics of shallow creep and its relationship with slope morphometry and weathering mantle thickness. The eccentricity values were spatially interpolated to visualize the evolution of creep activity over decades, which showed its significant spatial variability. Statistical analyses, including Pearson's and Spearman's correlation coefficients, were employed to examine the relationships between tree-ring eccentricity and various environmental factors. Results indicated that tree age influences the sensitivity to creep signals, with older trees showing increased eccentricity, suggesting a heightened response to creep movements. The study also explored the impact of precipitation on creep activity, identifying a weak, non-significant positive relationship. This comprehensive analysis enhances the understanding of shallow creep mechanisms and contributes to the broader field of dendrogeomorphology.

Building structures located in saline soil areas are more vulnerable to damage due to the combined effects of loading and sulfate erosion. Polypropylene fibers lithium slag concrete (PFLSC) exhibits good corrosion resistance, which can mitigate damage to building structures in saline soil areas. However, the eccentric compression behavior of PFLSC columns under sulfate erosion and external loading remains unclear. Therefore, in this study, an eccentric compression test was conducted on 10 PFLSC columns after exposure to combined sulfate erosion and external loading, with corrosion time and stress ratio as the research variables. The failure modes, load-displacement curves, failure loads, and strains of rebars were investigated. The results indicate that polypropylene fibers and lithium slag can effectively inhibit the corrosive effects of sulfates and significantly enhance the ductility and ultimate axial capacity of the specimens. Additionally, taking into account the prior load levels and the damage caused by sulfates to the concrete, a damage factor has been introduced to determine the strength of the concrete after undergoing loads and sulfate exposure. Ultimately, a model has been proposed to calculate the ultimate axial capacity of PFLSC columns under the coupled effects of loads and sulfuric acid. The calculated results showed excellent agreement with the corresponding experimental results. It provides reliable guidance for the durability design of PFLSC columns.

This study presents a nonmodel-based machine learning framework for estimating engineering demand parameters (EDPs) of eccentrically braced frames with soil-structure interaction effects. The objective is to estimate residual and peak story drift ratio, peak floor acceleration, and develop fragility curves using traditional regression equations and advanced machine-learning techniques. Correction coefficients are developed to improve prediction accuracy by accounting for soil-structure interaction. A comprehensive database, including incremental dynamic analysis results of 4- and 8-story frames, is developed, consisting of 109,841 data points. The database includes fixed-base models and models with various soil-structure interaction values, subjected to 44 far-field ground motions. Four scenarios are introduced considering various input variables to compare the impact of soil-structure interaction. Findings reveal the effects of soil-structure interaction features on the performance of machine learning algorithms, increasing by up to 17.61% of the coefficient of determination. Utilizing the predicted story drift ratio, two types of fragility curves indicate more precise predictions, emphasizing the impact of soil-structure interaction effects at lower damage levels. A graphical user interface has been developed to predict fragility curves based on various inputs to promote the practical use of machine learning in engineering. Two new 4-story frames are used as case studies, subjected to unseen ground motions to assess the application of trained machine learning algorithms. Prediction errors in input-output scenarios considering soilstructure interaction range from 3% to 18% for new frames. The proposed approach for predicting EDPs is further acknowledged by evaluating a real instrumented five-story steel frame office building.

Vibrators are widely used in agriculture, such as for vibrating trees to harvest fruits and nuts, or for vibrating screens to separate different materials (e.g. plants and soil or grain and debris) in the harvesting process. Traditional vibrators are bulky and configured with fixed mechanical transmission, so they cannot be precisely controlled and cannot adapt to different conditions, causing negative effects such as ineffective vibration or damaging tree barks. In this paper, a full-directional and lightweight electric vibrator is designed. The unidirectional vibration force is produced through the utilization of two centrifugal forces that are generated by the eccentric mass rotation of two motors. Firstly, the vibration direction can be adjusted to any direction by adjusting the meeting position of the two centrifugal forces. Secondly, the vibration force can be adjusted by changing the motor speed, as the centrifugal force is proportional to the square of the rotation speed. The vibrator is tested with laboratory bench experiment and with agricultural application for vibrating a tree. The prototype vibrator can produce 680N with the weight of 7.2kg, the force can be further improved by increasing the eccentric mass, increasing the rotation speed or decreasing the rotation arm length. The vibrator can be applied to smart agriculture, such as nut and fruit harvesting, or adaptive vibration screening.

The cyclic loading of foundation structures in sand leads to an accumulation of plastic deformations in the structures. For shallow foundations of high and slender structures such as wind energy converters (WECs), an accumulation of the plastic rotations is expected under cyclic eccentric loading that is imposed by wind loads, which could be crucial for the proof of serviceability. A practical approach to predict the behavior of shallow foundations under high-cycle eccentric loading is under research. In this paper, a numerical approach, the cyclic strain accumulation method (CSAM), which has been validated for cyclically loaded monopiles, is adopted for shallow foundations under eccentric cyclic loading. Modifications to the CSAM are described, which are necessary to apply it to shallow foundations. The results that are gained with the modified method are compared with a medium-scale model test, in which the deformations of a footing with a diameter of 2.0 m under eccentric one-way cyclic loading were investigated. It can be concluded that the CSAM can make realistic predictions and shows satisfying agreement with the measured cyclic behavior. Although more experiments are needed to finally validate the method, the CSAM could be a promising numerical approach to account for the cyclic behavior of shallow foundations under eccentric cyclic loading in sand.

Although soil stabilization with cement and lime is widely used to overcome the low shear strength of soft clay, which can cause severe damage to the infrastructures founded on such soils, such binders have severe impacts on the environment in terms of increasing emissions of carbon dioxide and the consumption of energy. Therefore, it is necessary to investigate soil improvement using sustainable materials such as byproducts or natural resources as alternatives to conventional binders-cement and lime. In this study, the combination of cement kiln dust as a byproduct and zeolite was used to produce an alkali-activated matrix. The results showed that the strength increased from 124 kPa for the untreated clay to 572 kPa for clay treated with 30% activated stabilizer agent (activated cement kiln dust). Moreover, incorporating zeolite as a partial replacement of the activated cement kiln dust increased the strength drastically to 960 and 2530 kPa for zeolite ratios of 0.1 and 0.6, respectively, which then decreased sharply to 1167 and 800 kPa with further increasing zeolite/pr to 0.8 and 1.0, respectively. The soil that was improved with the activated stabilizer agents was tested under footings subjected to eccentric loading. The results of large-scale loading tests showed clear improvements in terms of increasing the bearing capacity and decreasing the tilt of the footings. Also, a reduction occurred due to the eccentricity decreasing as a result of increasing the thickness of the treated soil layer beneath the footing.

Water table elevation leads to saturation of the soil surrounding the foundation. Saturated soil loses its load-bearing capacity due to suction reduction, becoming less stable and more prone to settling. This phenomenon can result in differential settlement, leading to uneven stress distribution on the structure. Over the last few years, substantial research efforts have been dedicated to analyzing the bearing capacity of saturated reinforced sand when subjected to loading at the foundation center, with limited attention given to unsaturated reinforced sand under eccentric loading. Eccentric loading can also result in additional stresses and moments that need to be considered in the design of the foundation to ensure its long-term integrity and functionality, especially when subjected to wetting conditions. Hence, this study investigated this aspect experimentally and numerically using the discrete element method (DEM) to uncover the intricate interactions between soil-reinforcement conditions, applied stress, and wetting-induced settlement. The results reveal that the geosynthetic reinforcement influences the extent of collapse settlement. While the reinforcement reduces collapse settlement, the enhancement is particularly notable when subjected to eccentric loadings. For both semisaturated and fully saturated conditions, the bearing capacity ratio (BCR) not only increases with the number of geosynthetic layers but also exhibits a higher rate for fully saturated sand than for the dry and semisaturated states. Unlike unreinforced sand where load eccentricity increases collapse settlement and differential settlement, reinforced sand experiences reduced settlement as load eccentricity increases. Finally, an empirical relationship by assessing the effect of the interface between the soil and the reinforcement layer was derived from regression analyses to predict the eccentric bearing capacity of strip footing under conditions of upward seepage. Alterations in pore-water pressure can influence the bearing capacity of shallow foundations. When the ground beneath a foundation reaches complete saturation, the in situ stresses that usually act as confining pressure experience an abrupt decrease. This phenomenon can induce additional settlements, which is very critical in foundation design applications, especially for foundations with eccentric loading, e.g., foundations subjected to wind load. Many shallow foundations are rested on deposits in coastal regions and along riverbanks. The failure due to the accumulation of pore-water pressure occurs when the shear stress applied by the superstructure surpasses the shear strength of the compromised soil. However, in cases where failure does not emerge, there remain issues related to serviceability and the potential for excessive settlement. This research demonstrates that the geosynthetic layers not only enhance the bearing capacity of strip footing but also show a greater improvement for eccentrically loadings in fully saturated sand compared to dry and semisaturated states.

By incorporating the bedding orientation of soil, this paper numerically investigates the effects of soil's anisotropic and heterogeneous behavior on strip footing under eccentric loading. The lower bound finite element limit analysis in association with second order cone programming is implemented to carry out the analysis by modeling cohesive soil as spatially random field. In order to generate the spatially random discretized soil domain, the well-known Cholesky decomposition technique is utilized. The probabilistic response is obtained by using the Monte Carlo simulation technique. The mean bearing capacity factor, failure probability of the footing for wide ranges of eccentricity, and soil heterogeneity are provided in design charts with respect to different bedding orientations. With the increase of eccentricity, the magnitude of the bearing capacity factor decreases in deterministic as well as probabilistic cases. At lower magnitudes of correlation lengths and eccentricity having different bedding orientations, significant variations are observed both in the magnitudes of mean bearing capacity factor and probability of failure; however, the variations are found to be minimized with the increase in the magnitudes of correlation lengths and eccentricity. Based on the obtained results, required factor of safety is evaluated for corresponding target probability by varying different bedding orientations.

This study aims to explore the significant impact of soil fabric anisotropy on the ultimate bearing capacity of eccentrically and obliquely loaded shallow foundations overlying a geosynthetic-reinforced granular deposit. For this purpose, the well-established lower bound theorems of limit analysis (LA) in conjunction with the finite elements (FE) formulations and second-order cone programming (SOCP) are exploited to perform the bearing capacity estimations. The consideration of the soil mass's inherently anisotropic response in the granular layer involves the utilization of distinct internal friction angles in various directions. The lower bound FELA framework adopted in this study incorporates both the pull-out and tensile mechanisms of failure in the reinforcement layer. The marked contribution of soil inherent anisotropy to the impacts of ultimate tensile strength (Tu) T u ) and embedment depth (u) u ) of the geosynthetic reinforcement on the failure mechanism, bearing capacity ratio (BCR), BCR ), and failure envelope of the overlying obliquely/eccentrically strip footing is rigorously examined and discussed. It is generally concluded that for a given embedment depth, failure envelopes of the surface footing in both V-H H and V-M M planes shrink appreciably with the increase in the soil anisotropy ratio as well as the decrease in the geosynthetic ultimate tensile strength. Moreover, the influence of soil inherent anisotropy on the overall bearing capacity of shallow foundations is more evident in the case of using strong reinforcement compared to the weak geosynthetic. The findings of this investigation demonstrate that overlooking the soil inherently anisotropic behaviour in the numerical analysis of shallow foundations would give rise to undesirable non-conservative and precarious designs.