Foundation Ground Research Articles

Study of effective location of shear wall in multi-storeyed buildings for optimum seismic response

In the seismic resistant design of high-rise structures, shear walls which are constructed along the height of the building are capable of transferring lateral forces from peripheral walls, floors, and roofs to the ground foundation. The main objective of the present study is to determine the effective location for shear walls in a multi-storey building for an optimum seismic response. The “Dynamic Response Spectrum method” of analysis of the building is done using ETABS. The effectiveness of shear walls has been studied by considering four different models. Model-I is a bare frame structural system without a shear wall and the other three models are dual-type structural systems with shear walls at different locations. In this study, a 16x16m plan with G+15 stories RC building with a total height of about 48m is analysed in zone V by providing shear walls of 250mm thick at different locations in the building. From the analysis results it is observed that the model with a shear wall placed at the centre of the building is more effective in resisting seismic forces when compared to other models.

The effect of Fernblock® in preventing blue-light-induced oxidative stress and cellular damage in retinal pigment epithelial cells is associated with NRF2 induction

Blue light exposure of the ocular apparatus is currently rising. This has motivated a growing concern about potential deleterious effects on different eye structures. To address this, ARPE-19 cells were used as a model of the retinal pigment epithelium and subjected to cumulative expositions of blue light. The most relevant cellular events previously associated with blue-light-induced damage were assessed, including alterations in cell morphology, viability, cell proliferation, oxidative stress, inflammation, and the induction of DNA repair cellular mechanisms. Consistent with previous reports, our results provide evidence of cellular alterations resulting from repeated exposure to blue light irradiation. In this context, we explored the potential protective properties of the vegetal extract from Polypodium leucotomos, Fernblock® (FB), using the widely known treatment with lutein as a reference for comparison. The only changes observed as a result of the sole treatment with either FB or lutein were a slight but significant increase in γH2AX+ cells and the raise in the nuclear levels of NRF2. Overall, our findings indicate that the treatment with FB (similarly to lutein) prior to blue light irradiation can alleviate blue-light-induced deleterious effects in RPE cells, specifically preventing the drop in both cell viability and percentage of EdU+ cells, as well as the increase in ROS generation, percentage of γH2AX+ nuclei (more efficiently with FB), and TNF-α secretion (the latter restored only by FB to similar levels to those of the control). On the contrary, the induction in the P21 expression upon blue light irradiation was not prevented neither by FB nor by lutein. Notably, the nuclear translocation of NRF2 induced by blue light was similar to that observed in cells pre-treated with FB, while lutein pre-treatment resulted in nuclear NRF2 levels similar to control cells, suggesting key differences in the mechanism of cellular protection exerted by these compounds. These results may represent the foundation ground for the use of FB as a new ingredient in the development of alternative prophylactic strategies for blue-light-associated diseases, a currently rising medical interest.

Introduction to the special issue: Allyship, advocacy, and social justice to support equality for marginalized groups in the workplace

Allyship is an important topic of growing interest in research and practice for management and organizations. However, research is still in its infancy, often fragmented across disciplines, and lacking conceptual clarity. The purpose of this special issue, “Allyship, Advocacy, and Social Justice to Support Equality for Marginalized Groups in the Workplace” is to enhance understanding of allies and allyship. We argue that allyship is a mechanism for centering social justice, reducing discrimination and inequality, and improving intergroup dynamics, inclusion, social cohesion, well-being, and organizational effectiveness. We note the importance of distinguishing between conceptualization of who is an ally and the different types of allyship in a brief review of the foundational grounding of the research stream. Next, we examine findings and insights from the eight papers in the special issue, examining how they move the field forward. These articles provide a springboard for understanding how to define, measure, and evaluate allyship, and for identifying key dynamics (e.g., marginalization, dominance, identity motivations), antecedents, consequences, contexts, and boundary conditions. We conclude by identifying future research opportunities that leverage this special issue’s content and gaps to address. We believe that improving understanding of how to be an ally, what they do, and the conditions under which allyship is effective, is valuable for enhancing social relationships between and within marginalized and dominant groups in organizations and society.

Deformation causes of the Embankment-Bridge transition section in warm permafrost: The case study of a dry bridge along the Qinghai-Tibet railway

Differential embankment settlement and expansion joint failure in the embankment bridge transition section (EBTS) are two main issues endangering the safety of the Qinghai-Tibet Railway (QTR) in permafrost. A better understanding of the causes of EBTS deformation can offer valuable guidance for engineering maintenance. In this study, a comprehensive field investigation and a series of simulations were carried out to reveal the formation causes. The results revealed significant permafrost degradation beneath the EBTS after 15 years of operation, with temperatures nearing the thawing point. Despite contact between the abutment and beam end, the expansion joint exhibited continuous narrowing, particularly during the cold season. Permafrost degradation was primarily attributed to the heating effect of adjacent bridge structures. Foundation ground settlement emerged as the primary cause of embankment settlement in the transition section, contributing up to 80 % of the total settlement. Differential embankment settlement of the EBTS primarily stemmed from the uneven warming or thawing of permafrost, induced by the thermal impact of the adjacent bridge structures. The weakening of the transition section had a concentrated impact on embankment settlement within a 12-meter span behind the abutment, inducing approximately 30 % to 50 % of the embankment settlement. The backfill soils near the abutment experienced severe lateral frost heave in cold seasons. Horizontal displacement of the abutment caused by the lateral frost heave was identified as the main reason for expansion joint failure. Additional cooling measures are necessary to ensure the long-term stability of the EBTSs along the QTR, considering the faster degradation of ambient permafrost than expected. The findings offer valuable insights for the maintenance and design of railways in permafrost regions.

Numerical Modelling simulation technology of Nonlinear Multi-Field Coupled Ground Foundation

Contemporary civil engineering practices demand sophisticated computational tools to navigate the complexities of structural systems and their interactions with the ground. This paper introduces a novel numerical modelling simulation technology tailored for nonlinear multi-field coupled ground foundations. Ground foundations, pivotal interfaces between structures and underlying soil, undergo intricate interactions influenced by various physical phenomena, including soil-structure interaction, soil-structure-fluid interaction, and thermal effects. Traditional analytical methods often falter in capturing the nuanced nonlinear behavior of these coupled systems. Consequently, this paper proposes a comprehensive numerical modelling framework integrating advanced computational techniques to accurately simulate the complex interplay of multiple fields within ground foundations. The methodology incorporates finite element analysis, multi-physics coupling algorithms, and advanced constitutive models to capture the nonlinear behavior of soil, structure, and fluid interactions. Through detailed case studies and validation against experimental data, the efficacy and accuracy of the proposed simulation technology are demonstrated, emphasizing its potential to revolutionize the design and analysis of ground foundation systems in civil engineering applications. This paper represents a foundational contribution towards advancing the state-of-the-art in numerical modelling simulation technologies for nonlinear multi-field coupled ground foundations, fostering innovation and optimization in civil engineering practice.

Numerical Simulation of Compensation Injection Problems Near Deep Excavations

The stress-strain state (SSS) of the “ground foundation – foundation pit under the protection of a fence – compensation injection zone” system is complex, multifactorial and transforming in space. Taking into account a wide range of phenomena when changing the SSS of the soil base is associated with significant difficulties, especially without the use of numerical modeling using software and computer systems. Numerical modeling in the implementation of the finite element method (FEM) for the problems of complex interaction of a soil basis with underground structures during compensatory grouting makes it possible to assign injection zones in any position in space (horizontally, vertically, at an angle), determine the necessary injection parameters to achieve the building lifting of the soil basis when solving the inverse problem. In this study, using examples of numerical modeling of compensation grouting problems near the pit fence with different locations of existing buildings, the authors identified the determining factors affecting the distribution of internal forces in the enclosing structures of the excavation, as well as on the existing structures of the underground structure. The results of comparison of calculations in two-dimensional and three-dimensional formulations are presented, an increase in the bending moment of the retaining wall when carrying out work on compensatory injection by 187-279% is shown for different parameters of the distance to the grouting horizon. The results of the conducted studies confirm the need to take into account the increase in internal efforts during the work on compensatory injection in the structures of the pit fences when assigning reinforcement. In addition, in some cases it is necessary to provide additional protective measures to prevent a negative impact on the constructed underground structures to reduce emergency situations.

On the use of dispersion curves to determine the critical speed of railway tracks. Application to case studies

Trains may reach a so-called critical speed at which, in the absence of damping, the dynamic response of the entire railway infrastructure would grow without any bound. A train will have less impact on the track the more its speed is lower than the critical speed. Therefore, in terms of track maintenance, it is of vital importance to know the critical speed along the track before its construction.Following the results mathematically proved by Kausel et al. (2020), we present a procedure —referred to as the “CSC method”— to determine the critical speed of railway tracks. It is based on the dispersive characteristics of the railway track system, which consists of the track bed layers (including the ballast, subballast and form layers among others), the embankment and the foundation ground (which can be arbitrarily layered). We validate the CSC method by using measurements from the well-known real case of Ledsgard (Sweeden). This method is easier to be implemented than dynamic FEM models and requires less geotechnical parameters and computational time.The CSC method is applied to some case studies: We use it to estimate the critical speed of a typical high-speed line and to study the influence on the critical speed of (i) the height of the embankment and (ii) the presence and thickness of an upper ground layer with low shear wave velocity. In addition, the critical speed inferred for the typical high-speed line is corroborated with experimental results from a railway testing facility at 1:1 scale, which can be interpreted as further validation of the CSC method. Moreover, the robustness of this method is demonstrated by the fact that the trend of results from the latter calculations (cases i and ii) agrees with the expected ones.

Small-scale regional engineering geological study of the Czech Republic evaluating the relationship between slope gradients and engineering geological zones

The aim of the small-scale regional engineering geological study of the Czech Republic was to evaluate the relationship between slope gradient and engineering geological zones. The research motivation was to determine the average slope gradient, 25%, 50% (median) and 75% quantiles related to the different engineering geological zones. This scientific information is critical from the perspectives of engineering geology, geotechnical engineering, and foundation engineering because an increasing slope gradient evokes the need to create a cut respectively foundation excavation or another excavation in the geological structure, which increases the probability of occurrence of the problem in terms of differential settlement and bearing capacity of the structures. The research was carried out in the territory of the Czech Republic in 8 Quaternary zones with soil foundation ground and 10 pre-Quaternary zones with rocks and semi-rocks and their eluvia. A significant difference in the statistical characteristics of slope gradients was found in the group of Quaternary engineering geological zones (evaluated group I) compared to the group of pre-Quaternary zones (evaluated group II). The value range of the average slope gradient was 1.65° (16.9%) to 5.89° (60.3%) for the Quaternary engineering geological zones (soil foundation ground), representing 43.4% difference. Whereas for the over-quaternary engineering geological zones (rocks, semi-rocks and their eluvia), the difference was much higher, 3.59° (36.8%) to 9.76° (100%—value determined as a referential because it was the maximum), which is also reflected in a more significant percentage difference of 63.2%.

Composite Foundation Settlement Prediction Based on LSTM–Transformer Model for CFG

Roadbed construction typically employs layered and staged filling, characterized by a periodic feature of ‘layered filling—filling interval’. The load and settlement histories established during staged construction offer crucial insights into long-term deformation under filling loads. However, models often rely solely on post-construction settlement data, neglecting the rich filling data. To accurately predict composite foundation ground (CFG) settlement, an LSTM–Transformer deep learning model is used. Five factors from the ‘fill height–time–foundation settlement’ curve are extracted as input variables. The first-layer LSTM model’s gate units capture long-term dependencies, while the second-layer Transformer model’s self-attention mechanism focuses on key features, efficiently and accurately predicting ground settlement. The model is trained and analyzed based on the newly constructed Changsha–Zhuzhou–Xiangtan intercity railway section CSLLXZQ-1, which has a CFG pile composite foundation. The research shows that the proposed LSTM–Transformer model for the settlement prediction of composite foundations has an average absolute error, mean absolute percentage error, and root mean square error of 0.224, 0.563%, and 0.274, respectively. Compared to SVM, LSTM, and Transformer neural network models, it demonstrates higher prediction accuracy, indicating better reliability and practicality. This can provide a new approach and method for the settlement prediction of newly constructed CFG composite foundations.

Centrifuge model tests on the effect of soft foundation ground in block-type quay walls subjected to earthquake

Centrifuge model tests on the effect of soft foundation ground in block-type quay walls subjected to earthquake

A Study on Causes and Stability of Masonry Retaining Walls by Case Analysis

Masonry retaining walls, which have been used since long time, have recently been widely used in the construction of small complexesas an easy-to-purchase material and eco-friendly structure. Disasters owing to the collapse of these masonry retaining walls have frequently occurred over time. The purpose of this study is to quantitatively evaluate the causes for the collapse of masonry retainingwalls by collecting and analyzing collapse data using collapse phenomenon field trips, literature review, and search tools, and to use this analysis data, to suggest measures to prevent the collapse of masonry retaining walls. As a result of collecting and analyzing collapse case data, this study found that the main causes of masonry retaining wall collapse were the loss of foundation ground (scour), ground displacement owing to the excavation of adjacent land, settlement owing to ground softening because of rainfallinfiltration, poor drainage, and inclination of stonework. The causes for collapse were of eight types, including slope sliding additionalloading, and vibration, and 16 types when literature data were included. An analysis of the collapse frequency based on the causes for collapse revealed that the two causes for collapse, foundation and drainage, accounted for approximately 60% of the total cause,and measures for stability and Governing law of critical factor were proposed using this result.

A Practitioner Approach to Modeling and Teaching Servant-Leadership

Servant-leadership is increasingly being taught in colleges, universities, and elsewhere. Approaches to teaching vary, but often involve a combination of reading, writing, modeling and practicing it. As college professors, working primarily with graduate students, we have learned over the years that teaching servant-leadership includes a strong effort at modeling it for students. In this essay, we share our approaches in how we structure servant-leadership courses. Some elements include Community, Relevant Learning, Ethically-Driven, Coaching/Mentoring Focus, Humor, Growth over Product, and Mutual Respect of Intellectual Capital.
 The selection and structure of key learning materials is also a crucial aspect of teaching and modeling servant-leadership in courses. The inclusion of key texts by Robert K. Greenleaf, such as Servant-Leadership, and On Becoming a Servant-Leader provide an important foundation grounding, as does Journey to the East, by Hermann Hesse (the book that inspired Robert Greenleaf in coining the term, servant-leader. The practice of silence, as an aid to becoming a better listener, has also proven to be most helpful. The servant-leader classroom is so much more than creating a culture of ‘let’s all get along’. Diving into the literature on the topic, building examples and assignments into the course structure and content, and then modeling the principles of the discipline helps to facilitate a culture of care. Servant-leadership is certainly easier to talk about than to consistently do. But it’s more than worth it to try—as we open the minds and hearts of our students (and ourselves) to the lifestyle of serving.

Discussion on the Exploration of Grouting Construction Technology in Water Conservancy Engineeringe

At present, with the rapid development speed and development space of water conservancy projects in China, the foundation that can be used for the construction of water conservancy projects is less and less. As the foundation grouting technology has been applied in a wider range and more attention has been paid to the adaptability of the foundation grouting technology and geological conditions, the requirements on the foundation are usually very harsh in water conservancy projects, and their foundations must be strictly treated through special requirements in order to achieve the performance requirements of seepage prevention and stability that water conservancy projects must have. Therefore, it is very important to use the appropriate technology to deal with the foundation of the water conservancy project, and it is necessary to fully prepare and deal with the waterproofing of the ground foundation in the early stage of the water conservancy project construction, otherwise it will bring many difficult problems to the construction unit. Therefore, the foundation grouting construction technology plays a very important role in the construction of water conservancy projects. This paper aims to briefly analyze and discuss the foundation grouting construction technology of water conservancy projects.

Thermal performance of wedge pile slab foundation without frost protection insulation and highly insulated slab on ground floor – first year measurements

In the Nordic countries frost insulation is necessary if the foundation is above the frost-free depth. The thermal performance of the pile foundations is between a shallow ground foundation and a frost wall foundation. The pile ends extend below the frost line to help insulate the ground beneath a building’s foundation. The ends of the piles extend below the frost line to prevent the foundation of the building from frost heaving. However, there may be a risk that the ground below the slab on ground may freeze and frost heaving may occur there. The risk of frost below the slab on ground floor and/or basement increases because increasing thickness of floor insulation remarkable influences frost insulation dimensioning. In this study a 6.5 × 17-meter size uninsulated wedge pile slab foundation with highly insulated (U=0.07 W/(m2·K)) slab on ground floor was constructed for a heated building and equipped with temperature, soil moisture, relative humidity, and heat flux sensors. Seven temperature measurement piles below the building and one for reference 8 meters far from the building reached a depth of up to 3.2 meters, which is deeper than the usual 1.4 m depth to avoid freezing in foundation design. In three places, the temperature below the insulation of slab on the ground is measured at 0.5 meters step up to 3 meters from the outer wall of the building. The first-year measurement results showed that temperature did not drop below the zero degree below the foundation and floor. Even though during winter the daily average absolute minimum temperature was -24 °C the sum of degree hours below the zero degree was -7300 °Ch. The historic 50-year absolute sum of minimum degree hours below the zero degree was -28600 °Ch. In addition to real measurement results this three-dimensional temperature sensor field helps to calibrate and validate dynamic model for temperature simulation of thermal performance of wedge pile slab foundation without frost protection insulation and highly insulated slab on ground floor.

The dynamic analysis of fixed deep-water platform

The industrial progress is closely related with active using of hydrocarbons more than half of reserves of which lie in rock formations beneath seabed or ocean floor. For oil production at the great depth of immersion oil production fixed platforms are used most often. But using of such technological structures is not limited only to interest of oil and natural gas industry whereas they are important for navigation and military purposes. Offshore fixed platforms are exposed to effects of a high seismicity, wind, waves, strong undercurrents and an impulse impact during the movement of ice fields especially when exploitation in northern seas. The impact of different factors on the value of the period of natural oscillations ofthe offshore fixed deep-water ice-resistant platform with the depth of immersion 120 m that rests on the pile foundation was researched. Two discrete idealized models of the platform were used for the analysis: the first model that was implemented without taking into account the flexibility of the foundation and the second model where the flexibility of the pile foundation and the action of ground foundation were taking into account by the addition of elastic links that simulate the elastic connection between joints. Also, impacts of the connected mass of water media that was modeled in the form of additional distributed joints mass and the impact of the ice field that was modeled by the addition of additional links were investigated. The analysis showsthat values of periods of natural oscillations form increase by 8-20% when the flexibility of the pile foundation was taken into account; increase by 9-100% when the impact of the connected mass of water media was taken into account; decrease by 9-100% when the impact of the ice field and water media were taken into accountthat is significant when analyzing of stress-strain state of members of the structure.

Clayey Soil Improvement with Polyethylene Terephthalate (PET) Waste

Population expansion and the development of technology have led to an increase in construction activities. In many cases, foundation grounds do not have a high enough bearing capacity and are not capable of ensuring the safe exploitation of the construction. A soil with poor mechanical characteristics must be improved using various methods, such as adding hydraulic binders (lime and cement), natural fibres, or more recently, plastic waste materials. This work aims to study the behaviour of plastic waste materials made from polyethylene terephthalate (PET) in soil improvement. Thus, the mechanical characteristics of a clay improved with shredded PET were studied. PET was added in relation to the dry mass of the clay, in percentages of 2%, 4% and 6%. The studied clay was collected from a construction site around Cluj-Napoca, Romania, from a depth of 1 ÷ 10 m. PET was provided by a local plastic waste repository. It comes from recycled water, beer and soda bottles and was cleaned using specific methods for cleaning and recycling plastic waste. PET was shredded into irregular shapes with sizes ranging from 3 mm to 12 mm and was randomly distributed in the test specimens. Compression and direct shear tests were carried out to study the compressibility and shear parameters of the improved soil (internal friction angle and cohesion). The experimental results showed an improvement in the mechanical characteristics of the clay even at a low PET addition of 2% and 4%. This method can contribute to solving two current problems of the modern world: reducing pollution by recycling plastic waste materials and using them to improve the mechanical characteristics of soil.

Analysing The Diverse Perspectives On Balance Of Power

The concept of the Balance of Power has long been a significant factor in the realm of international politics. This article examines the evolution of power dynamics across time, starting with its inception in the early modern European state system and extending to its expansion on the global scale. The study delves further into the intricate dynamics of power equilibrium by examining the impact of various perspectives on its implementation and perception. The Peace of Westphalia, which was created in 1648 after the end of the Thirty Years' War, introduced a framework whereby governments aimed to prevent the dominance of a single power and maintain peace via the formation of alliances and the division of power. This event served as the foundational ground for the concept of the balance of power in historical context. The notion, which was originally centred in Europe, ultimately evolved into a fundamental principle of international law. The article also investigates several perspectives on power dynamics, with a specific emphasis on the realism paradigm that prioritizes state-centred evaluations of power and self-interest. The examination also includes an analysis of the liberal perspective, which prioritizes international institutions and collaborative endeavors aimed at maintaining stability. Furthermore, it engages with the constructivist paradigm, which emphasizes the significance of ideas, identities, and norms in shaping international power dynamics and conduct.

Internal force and damage analysis of foundation of steel–concrete wind turbine tower

The internal cavity of the foundation of a steel–concrete composite wind turbine tower (WTT) is designed to facilitate prestressed construction. The load-bearing mechanisms of this type of foundation are different from those of ring-type and anchor-type foundations commonly used in steel WTTs. Based on a real project, an integrated model of a prestressed tower–foundation–ground was built using the finite-element software Abaqus. The internal force and damage in the foundation of a steel–concrete WTT under extreme load conditions were studied using the static loading method. Under extreme load conditions, prestressed reinforcements were found to have little impact on the local pressure at the anchor end of the foundation. Prestressing the reinforcement effectively prevented concrete cracking and tower deformation. For areas experiencing extreme loads on both sides, simplified calculations for stress and reinforcement can be performed using calculation formulae for the bracket.

The Prediction of Transmission Towers’ Foundation Ground Subsidence in the Salt Lake Area Based on Multi-Temporal Interferometric Synthetic Aperture Radar and Deep Learning

Displacement prediction of transmission towers is essential for the early warning of transmission network deformation. However, there is still a lack of prediction on the ground subsidence of the tower foundation. In this study, we first used the multi-temporal interferometric synthetic aperture radar (MT-InSAR) approach to acquire time series deformation for the transmission lines in the Salt Lake area. Based on the K-shape clustering method and field investigation results, towers #95 and #151 with representative foundation deformation characteristics were selected for displacement prediction. Combined with field investigations and the characteristics of saline soil in the Salt Lake area, the trigger factors of transmission tower deformation were analyzed. Then, the displacement and trigger factors of the transmission tower were decomposed by variational mode decomposition (VMD), which could closely connect the characteristics of the foundation saline soil with the influence of the trigger factors. To analyze the contribution of each trigger factor, the maximum information coefficient (MIC) was quantified, and the best choice was made. Finally, the hyperparameters of the long short-term memory (LSTM) neural networks were optimized using a convolutional neural network (CNN) and the grey wolf optimizer (GWO). The findings reveal that the refined deep learning models outperform the initial model in generalization potential and prediction precision, with the CNN–LSTM model demonstrating the highest accuracy in predicting the total displacement of tower #151 (RMSE and R2 for the validation set are 0.485 and 0.972, respectively). Given the scant research on the multifactorial influence on the ground subsidence displacement of transmission towers, this study’s methodology offers a novel perspective for monitoring and early warning of ground subsidence disasters in transmission networks.

Assessment of the technical condition of bridges and their ground foundations using the electrical resistivity tomography and the passive seismic standing wave method

The results of geophysical studies are presented, the purpose of which was to assess the technical condition of two railroad bridges and their ground foundations in permafrost areas. It is shown that the passive seismic standing wave method makes it possible to determine the frequencies and shapes of several flexural modes of the bridge's natural vibrations, which can be used to assess its technical condition. This method is reduced to the recording of acoustic noise on the surface of the study object and accumulating the amplitude spectra of a large number of noise records. This makes it possible to extract from the noise standing waves formed in the study object under its influence and determine their parameters. The electrotomography of the soil foundation makes it possible to identify zones of thawed soils in the permafrost, which, together with the analysis of the bridge's natural modes, makes it possible to assess the potential danger of stability loss of its supports.