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The purpose of this study was to investigate the likely causes of failure of some sections of road pavements in Ajaokuta, Northcentral Nigeria. This was achieved through a geotechnical assessment of subgrade soils in affected areas.

The methods entailed field and laboratory methods and statistical analysis. Subgrade soil samples were retrieved from a depth of 1,000 mm beneath the failed portions using a hang auger. The soils were analyzed for natural moisture content (NMC), Atterberg limit (liquid limit, plastic limit and linear shrinkage), grain size distribution, compaction and California bearing ratio (CBR), respectively.

The results of the geotechnical tests ranged from NMC (12.5%–19.4%), sand (84%–98%), fines (2%–16%), LL (16.0%–32.2%), PL (17%–27.5%), LS (2.7%–6.4%), PI (2.5%–18.4%), maximum dry density (1756 kg/m2–1961 kg/m2), optimum moisture content (13.2%–20.2%), unsoaked CBR (15.5%–30.5%) and soaked CBR (8%–22%), respectively. Pearson’s correlation coefficient performed on the variables showed that some parameters exhibited a strong positive correlation with r2 > 0.5.

Funding was the main limitation.

Comparing the results with Nigerian standards for road construction, and the AASHTO classification scheme, the subgrade soils are competent and possess excellent to good properties. The soils also exhibited very low plasticity, a high percentage of sand, high CBR and low NMC, which implies that it has the strength required for road pavement subgrades. The likely causes of the failures are, therefore, due to the use of poor construction materials, technical incompetence and poor compaction of sub-base materials, respectively.

This study aims to investigate the behavior of different types of stone columns, including the short and floating columns, as well as the ordinary and the geosynthetic encased stone columns (OSC and GESC). The effectiveness of the geosynthetic encasement and the impact of the installation using the lateral expansion method on the column performance is evaluated through a three-dimensional (3D) unit cell numerical analysis.

A full 3D numerical analysis is carried out using the explicit finite element code PLAXIS 3D to examine the installation influence on settlement reduction (ß), lateral displacement (U_x) and vertical displacement (U_z) relative to different values of lateral expansion of the column (0% to 15%).

The findings demonstrate the superior performance of GESC, particularly short columns outperforming floating counterparts. This enhanced performance is attributed to the combined effects of geosynthetic encasement and increased lateral expansion. Notably, these strategies contribute significantly to decreasing lateral displacement (U_x) at the column’s edge and reducing vertical displacement (U_z) under the rigid footing.

In contrast to previous studies that examined the installation effect of OSC contexts, this paper presents a comprehensive investigation into the effect of geosynthetic encasement and the installation effects using the lateral expansion method in very soft soil, using 3D numerical simulation. The study emphasizes the significance of the consideration of geosynthetic encasement and lateral expansion of the column during the design process to enhance column performance.

This paper aims to investigate the responses of single piles and pile groups due to tunneling-induced ground movements in a two-layered soil system. The analyses mainly focus on the additional single pile responses in terms of bending moment, lateral deflection, axial force, shaft resistance and pile settlement. Subsequently, a series of parametric studies were carried out to better understand the responses of single piles induced by tunneling. To give further understanding regarding the pile groups, a 2 × 2 pile group with two different pile head conditions, namely, free and capped, was considered.

Using the PLAXIS three-dimensional (3D) software, a full 3D numerical modeling is performed to investigate the effects of ground movements caused by tunneling on adjacent pile foundations. The numerical model was validated using centrifuge test data found in the literature. The relevance of the 3D model is also judged by comparison with the 2D plane strain model using the PLAXIS 2D code.

The numerical test results reveal that tunneling induces significant displacements and internal forces in nearby piles. The magnitude and distribution of internal forces depend mainly on the position of the pile toe relative to the tunnel depth and the distance between the pile and the vertical axis of the tunnel. As the volume loss increases from 1% to 3%, the apparent loss of pile capacity increases from 11% to 20%. By increasing the pile length from 0.5 to 1.5 times, the tunnel depth, the maximum pile settlement and lateral deflection decrease by about 63% and 18%, respectively. On the other hand, the maximum bending moment and axial load increase by about 7 and 13 times, respectively. When the pile is located at a distance of 2.5 times the tunnel diameter (Dt), the additional pile responses become insignificant. It was found that an increase in tunnel depth from 1.5Dt to 2.5Dt (with a pile length of 3Dt) increases the maximum lateral deflection by about 420%. Regarding the interaction between tunneling and group of piles, a positive group effect was observed with a significant reduction of the internal forces in rear piles. The maximum bending moment of the front piles was found to be higher than that of the rear piles by about 47%.

Soil is a complex material that shows differently in primary loading, unloading and reloading with stress-dependent stiffness. This general behavior was not possibly being accounted for in simple elastic perfectly plastic Mohr–Coulomb model which is often used to predict the behavior of soils. Thus, in the present study, the more advanced hardening soil model with small-strain stiffness (HSsmall) is used to model the non-linear stress–strain soil behavior. Moreover, unlike previous studies THAT are usually based on the assumption that the soil is homogeneous and using numerical methods by decoupled loadings under plane strain conditions; in this study, the pile responses have been exhaustively investigated in a two-layered soil system using a fully coupled 3D numerical analysis that takes into account the real interactions between tunneling and pile foundations. The paper presents a distinctive set of findings and insights that provide valuable guidance for the design and construction of shield tunnels passing through pile foundations.

The purpose of this paper is to review cases of artificial reefs built through additive manufacturing (AM) technologies and analyse their ecological goals, fabrication process, materials, structural design features and implementation location to determine predominant parameters, environmental impacts, advantages, and limitations.

The review analysed 16 cases of artificial reefs from both temperate and tropical regions. These were categorised based on the AM process used, the mortar material used (crucial for biological applications), the structural design features and the location of implementation. These parameters are assessed to determine how effectively the designs meet the stipulated ecological goals, how AM technologies demonstrate their potential in comparison to conventional methods and the preference locations of these implementations.

The overview revealed that the dominant artificial reef implementation occurs in the Mediterranean and Atlantic Seas, both accounting for 24%. The remaining cases were in the Australian Sea (20%), the South Asia Sea (12%), the Persian Gulf and the Pacific Ocean, both with 8%, and the Indian Sea with 4% of all the cases studied. It was concluded that fused filament fabrication, binder jetting and material extrusion represent the main AM processes used to build artificial reefs. Cementitious materials, ceramics, polymers and geopolymer formulations were used, incorporating aggregates from mineral residues, biological wastes and pozzolan materials, to reduce environmental impacts, promote the circular economy and be more beneficial for marine ecosystems. The evaluation ranking assessed how well their design and materials align with their ecological goals, demonstrating that five cases were ranked with high effectiveness, ten projects with moderate effectiveness and one case with low effectiveness.

AM represents an innovative method for marine restoration and management. It offers a rapid prototyping technique for design validation and enables the creation of highly complex shapes for habitat diversification while incorporating a diverse range of materials to benefit environmental and marine species’ habitats.

Present study aimed to integrate Geographic Information Systems (GIS) and Building Information Modeling (BIM) in conjunction with multicriteria decision-making (MCDM) to enhance infrastructure investment planning.

This analysis combines GIS databases with BIM simulations for a novel highway project. Around 150 potential alternatives were simulated, narrowed to 25 more effective routes and 3 options underwent in-depth analysis using PROMETHEE method for decision-making, based on environmental, cost and safety criteria, allowing for comprehensive cross-perspective comparisons.

A comprehensive framework proposed was validated through a case study. Demonstrating its adaptability with customizable parameters. It aids decision-making, cost estimation, environmental impact analysis and outcome prediction. Considering these critical factors, this study holds the potential to advance new techniques for assessment and planning railways, power lines, gas and water.

The study acknowledges limitations in GIS data quality, particularly in underdeveloped areas or regions with limited technology access. It also overlooks other pertinent variables, like social, economic, political and cultural issues. Thus, conclusions from these simulations may not entirely represent reality or diverse potential scenarios.

The proposed method automates decision-making, reducing subjectivity, aids in selecting effective alternatives and considers environmental criteria to mitigate negative impacts. Additionally, it minimizes costs and risks while demonstrating adaptability for assessing diverse infrastructures.

By integrating GIS and BIM data to support a MCDM workflow, this study proposes to fill the existing research gap in decision-making prioritization and mitigate subjective biases.

The purpose of this study is to conceptually integrate business to consumer (B2C) into business to business (B2B), with a holistic consumer-centric, technology-reinforced, long-term vision for tourism industries and companies to survive and succeed in the era of new technologies 4.0. The research suggests that the tourism-marketing-new technologies decision-making involves customers as the center of the design and decision process.

The research design includes a qualitative study with 94 in-depth interviews, a literature analysis and a conceptual proposition. The qualitative study follows the tourism consumer desire data analysis, from categorization to integration. The literature analysis applies a systematic literature review approach based on the 29 most up-to-date new-tech papers from peer-reviewed journals. The analysis compares qualitative research findings and literature analysis results and matches the new technology applications with consumer desire understanding. The conceptual framework of tourism marketing/advertising is proposed based on qualitative research and literature analysis.

The qualitative research deciphers that consumers, based on their imagination and memorization, desire therapy and sceneries and connect such desires to the empathetic and resonating advertising messages. The literature analysis synthesizes the new tech applications in tourism and matches the qualitative research findings with the deciphered desires in tourism. The conceptual model proposes that B2C should be integrated into B2B to provide value for both consumers and businesses and opens avenues of research on this topic.

This research has made the following theoretical contributions: it offers an in-depth understanding of consumer desire, often hidden or subconscious, in the field of tourism. Consumer desires regarding tourism are mostly subconscious and exist long before consumers are exposed to advertising messages. These desires reflect the search for therapy and sceneries and become “embodied” – they exist on multisensorial levels and become part of the body and life and will lead consumers into positive perceptions when marketing communications/advertisements resonate with them. In the latter case, they will subjectively judge advertising as “good,” regardless of the advertising design quality. The research also connects consumer research with a new technologies research review and proposes a conceptual framework to integrate business to consumer (B2C) with business to business (B2B). As such, the research makes theoretical contributions to the integration or the “boundary blurring” between B2C and B2B research and practical suggestions that involved industries and consumers may all benefit from such integration. Conceptually, there is a lack of discussions of the pitfalls of new technologies, a dearth of empirical verification of the applications of new technologies in the proposed fields and a shortage of discussions about ethical issues. Qualitative methods, offering an efficient tool for understanding consumer desires in the tourism industry, have their own limits, as discussed in previous research. The sample is limited to the state of New York population and may be influenced by geographic, demographic and psychological characteristics related to the region.

This research provides advertising practitioners, new technology innovators and tourism industries with a framework to face the combined challenges of understanding hidden consumer desires and applying adequate technologies that resonate with consumer desires to tackle relevant issues. The conceptual proposition of this research fills the gap between qualitative consumer research without concrete practical resolution and new technologies applications without in-depth consumer understanding. Through the conceptual framework, the author provides insights into how industries may benefit from consumer understanding. The business relationships among the industries of marketing, tourism and new technologies should be centered around consumers. Thus, B2C and B2B should be naturally integrated into business practices.

Social implications of this research include three major points: first, the understanding of consumer desire for therapeutic power in tourism, which invites more attention to tourism as part of social well-being design instead of a purely for-profit business. Second, a profound comprehension of what consumers need and desire, without which the applications of new technologies may cause severe societal problems. Third, a way to tailor to consumers’ individuality and desires for advertising/marketing that may be considered abusive, stressful and socially destructive if applied in a nonpersonal manner.

Conceptually, this research adds consumer desire, an originally B2C concept, to the B2B context regarding the new technology applications in tourism marketing/advertising. It contributes to the B2B literature by proposing a strong consumer-centric approach, especially the consumer desire understanding, that is not yet investigated in the B2B literature; and a combination of empirical study and literature analysis and the matching of the two for better practice of advertising/marketing, tourism and new technologies applications.

The study aims to investigate the effects of pre-loading histories (pre-shearing and pre-consolidation) on the liquefaction behaviour of saturated loose sand via discrete element method (DEM) simulations.

The pre-shearing history is mimicked under drained conditions (triaxial compression) with different pre-shearing strain levels ranging from 0% to 2%. The pre-consolidation history is mimicked by increasing the isotropic compression to different levels ranging from 100 kPa to 300 kPa. The macroscopic and microscopic behaviours are analysed and compared.

Temporary liquefaction, or quasi-steady state (QSS), is observed in most samples. A higher pre-shearing or pre-consolidation level can provide higher liquefaction resistance. The ultimate state line is found to be unique and independent of the pre-loading histories in stress space. The Lade instability line prematurely predicts the onset of liquefaction for all samples, both with and without pre-loading histories. The redundancy index is an effective microscopic indicator to monitor liquefaction, and the onset of the liquefaction corresponds to the phase transition state where the value of redundancy index is one, which is true for all cases irrespective of the proportions of sliding contacts.

The liquefaction behaviour of granular materials still remains elusive, especially concerning the effects of pre-loading histories on soils. Furthermore, the investigation of the effects of pre-consolidation histories on undrained behaviour and its comparison to pre-sheared samples is rarely reported in the DEM literature.

This research aims to propose a model for the complex decision-making involved in the ecological restoration of mega-infrastructure (e.g. railway engineering). This model is based on multi-source heterogeneous data and will enable stakeholders to solve practical problems in decision-making processes and prevent delayed responses to the demand for ecological restoration.

Based on the principle of complexity degradation, this research collects and brings together multi-source heterogeneous data, including meteorological station data, remote sensing image data, railway engineering ecological risk text data and ecological restoration text data. Further, this research establishes an ecological restoration plan library to form input feature vectors. Random forest is used for classification decisions. The ecological restoration technologies and restoration plant species suitable for different regions are generated.

This research can effectively assist managers of mega-infrastructure projects in making ecological restoration decisions. The accuracy of the model reaches 0.83. Based on the natural environment and construction disturbances in different regions, this model can determine suitable types of trees, shrubs and herbs for planting, as well as the corresponding ecological restoration technologies needed.

Managers should pay attention to the multiple types of data generated in different stages of megaproject and identify the internal relationships between these multi-source heterogeneous data, which provides a decision-making basis for complex management decisions. The coupling between ecological restoration technologies and restoration plant species is also an important factor in improving the efficiency of ecological compensation.

Unlike previous studies, which have selected a typical section of a railway for specialized analysis, the complex decision-making model for ecological restoration proposed in this research has wider geographical applicability and can better meet the diverse ecological restoration needs of railway projects that span large regions.

This paper aims to formally conceptualize service mega-disruptions as any far-reaching and unforeseen general environmental stressor or threat that impacts a service organization’s ability to provide a desired level of service. The authors differentiate sudden large-scale general environmental threats from traditional service failures in scope and scale of impact via number of customers and sectors affected and duration and speed of the disruption.

This paper draws from service recovery theory to build a conceptual model of service mega-disruptions. The resulting conceptual model maps service failure recovery strategies against a service mega-disruption recovery approach to examine consumer response to changes in service value. This work further articulates additional research needs including conceptualization, measurement and methods as traditional drivers of service recovery and the value of the service experience change in response to service mega-disruptions.

This work proposes a research agenda to investigate whether service mega-disruptions can bypass the need for service recovery due to a consumer self-moderating process. As past research shows, the less control a service provider has over a failure, the more customers attribute fault to the situation and transfer blame away from an organization. This paper suggests that this self-moderating process disrupts the need for service providers to court forgiveness for a failure with perceptions of similarity and controllability providing an alternate pathway to customer forgiveness. Similarly, it is suggested that service mega-disruptions play a role in transforming service ecosystems into tighter, more contractual systems with less agency for service providers and poorer ability to adjust to market conditions. The duration and longevity of effects on service providers’ control, agency and ability to adjust following a service mega-disruption must be researched further.

This paper builds theory to develop a conceptual model of service mega-disruptions and their role in customer engagement and reshaping the service ecosystem. This paper culminates in the proposition of a research agenda that aims to build research capacity among services marketing scholars as service providers’ coordination and market conditions are challenged by service mega-disruptions.