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This method will become a new development trend in subgrade structure design for high speed railways.

This paper summarizes the structural types and design methods of subgrade bed for high speed railways in China, Japan, France, Germany, the United States and other countries based on the study and analysis of existing literature and combined with the research results and practices of high speed railway subgrade engineering at home and abroad.

It is found that in foreign countries, the layered reinforced structure is generally adopted for the subgrade bed of high speed railways, and the unified double-layer or multi-layer structure is adopted for the surface layer of subgrade bed, while the simple structure is adopted in China; in foreign countries, different inspection parameters are adopted to evaluate the compaction state of fillers according to their respective understanding and practice, while in China, compaction coefficient, subsoil coefficient and dynamic deformation modulus are adopted for such evaluation; in foreign countries, the subgrade top deformation control method, the subgrade bottom deformation control method, the subsurface fill strength control method are mainly adopted in subgrade bed structure design of high speed railways, while in China, dynamic deformation control of subgrade surface and dynamic strain control of subgrade bed bottom layer is adopted in the design. However, the cumulative deformation of subgrade caused by train cyclic vibration load is not considered in the existing design methods.

This paper introduces a new subgrade structure design method based on whole-process dynamics analysis that meets subgrade functional requirements and is established on the basis of the existing research at home and abroad on prediction methods for cumulative deformation of subgrade soil.

Large displacement misalignment under the action of active faults can cause complex three-dimensional deformation in subway tunnels, resulting in severe damage, distortion and misalignment. There is no developed system of fortification and related codes to follow. There are scientific problems and technical challenges in this field that have never been encountered in past research and practices.

This paper adopted a self-designed large-scale active fault dislocation simulation loading system to conduct a similar model test of the tunnel under active fault dislocation based on the open-cut tunnel project of the Urumqi Rail Transit Line 2, which passes through the Jiujiawan normal fault. The test simulated the subway tunnel passing through the normal fault, which is inclined at 60°. This research compared and analyzed the differences in mechanical behavior between two types of lining section: the open-cut double-line box tunnel and the modified double-line box arch tunnel. The structural response and failure characteristics of the open-cut segmented lining of the tunnel under the stick-slip part of the normal fault were studied.

The results indicated that the double-line box arch tunnel improved the shear and longitudinal bending performance. Longitudinal cracks were mainly distributed in the baseplate, wall foot and arch foot, and the crack position was basically consistent with the longitudinal distribution of surrounding rock pressure. This indicated that the longitudinal cracks were due to the large local load of the cross-section of the structure, leading to an excessive local bending moment of the structure, which resulted in large eccentric failure of the lining and formation of longitudinal cracks. Compared with the ordinary box section tunnel, the improved double-line box arch tunnel significantly reduced the destroyed and damage areas of the hanging wall and footwall. The damage area and crack length were reduced by 39 and 59.3%, respectively. This indicates that the improved double-line box arch tunnel had good anti-sliding performance.

This paper adopted a self-designed large-scale active fault dislocation simulation loading system to conduct a similar model test of the tunnel under active fault dislocation. This system increased the similarity ratio of the test model, improved the dislocation loading rate and optimized the simulation scheme of the segmented flexible lining and other key factors affecting the test. It is of great scientific significance and engineering value to investigate the structure of subway tunnels under active fault misalignment, to study its force characteristics and damage modes, and to provide a technical reserve for the design and construction of subway tunnels through active faults.

The estimation of market value of intangible benefits of afforestation has always been a challenging task, and the contingent valuation method is a popular method used in environmental assessment. The NTPC set up a coal-based power plant in Korba, India and planted 1.6 million trees on 19% of the project area.

The individual's mean and median willingness to pay (WTP) for four intangible benefits, namely, pollution control (PC), improvement in underground water level (IUGWL), soil conservation and remediation (SCR) in addition to total WTP from the afforestation program of NTPC were estimated using a customized procedure for logit model based upon respondent's age, education, occupation, income and bid amount asked to pay. Stratified multistage random sampling has been used to select the respondents.

The procedure increases the number of respondents who are willing to pay as compared to conventional CVM. The finding of the study shows that the highest WTP was observed for PC (Rs. 462.84 per month per household) followed by SCR and IUGWL, whereas for total WTP it was Rs. 972.60.

The proposed customized procedure and the results thereof would be useful in improving the WTP estimates for other similar studies in order to conserve the environment.

This paper aims to review the known and anticipated medical geology problems in Ghana, to highlight the impact of some trace elements on human health and to reveal some essential aspects of medical geology on health.

Literature and empirical studies relating to medical geological issues in Ghana were reviewed. Secondary data were used in the present study such as case studies, reports, geological bulletins and published research studies.

High levels of heavy metals including arsenic, cadmium and mercury in gold extraction processes through artisanal small-scale mining have contributed to high concentrations of toxic elements in the environment. The distribution and availability of these elements in the environment are facilitated by the geological, chemical and local environmental activities that are irregularly spread exposing people mining areas to pollutions. Exposures to these elements in above and below baseline levels contributed to health implications including fluorosis, intellectual or developmental disability and death in some regions of Ghana. Cardiovascular and cerebrovascular diseases linked to mining activities were also presented in this study. Similarly, non-communicable diseases can affect many people if correct measures are not considered. Following the geometric increase in mining activities, it is anticipated that deleterious environmental and health impacts associated with mining may persist in mining areas in Ghana. Reported implications and continuous contamination of water bodies in mining areas could result in high pollution levels beyond treatment for human use or destroy aquatic habitats and aquatic lives through acid drainage. Above-threshold concentrations of heavy metals in soils could bio-accumulate in crops, and this could pose deleterious public health implications on consumers. Continuous effects posed on the environment and public health may prompt communities, regulatory institutions and government to reduce or ban mineral development.

This review has significantly revealed potential public health issues from the impact on the natural environment and recommends that medical geologists work together with medical workers to devise preventive and therapeutic techniques to address many geology-related-health issues in Ghana.

The purpose of this paper is to make the reader think about the consequences of food scarcity and how science would deal with the situation portrayed through Dr Spock's Food Festival set in Tokyo 2050.

The paper takes the form of a trends analysis perspective.

The authors explain the circumstances (or drivers) of how food scarcity would lead to particular future state. The paper portrays eight driving forces from increased urbanisation to a knowledgeable society.

What if it did occur as molecular gastronomy and the desire for new experiences are core values of today's restaurant industry.

The purpose of this paper is to analyze the rationale for using social engineering as a tool to impact the nationalization of workforce in the United Arab Emirates (UAE).

Interpretative and exploratory approaches have been employed for this research. Accordingly, the study has extensively reviewed government documents, reports of international organizations and relevant academic literature, including journal articles, conference papers and unpublished dissertations.

The findings show that the UAE Government has initiated multiple policies and programs to enhance participation of indigenous Emiratis in the burgeoning labor market which has been hitherto dominated by the expatriates. However, while the Emiratization programs are on the verge of fulfilling the targets in the public sector job market, significant gaps exist between the targets and accomplishments in the private sector, causing policy concern.

This paper links theoretical insights from the social engineering model used in the social sciences research to analyze the dynamics of workforce nationalization. The study will be helpful to inform further empirical research in this area.

Despite the growing importance of workplace spirituality, organisations have been reluctant to integrate spirituality into their workplaces; this paper discusses how to integrate spirituality into the workplace.

This is a theoretical paper that builds its arguments on the synthesis of workplace spirituality and contemporary management paradigms.

The study argues that workplace spirituality is an extremely important driving force for the sustainable and healthy growth of any organisation; however, infusing workplace spirituality into companies in the industrial and digital eras would be a futile effort, as industrial organisations are built on an ethos highly incongruent with spiritual principles. Therefore, in the post-digital era, spirituality-driven organisations (SDOs) will emerge, marking the beginning of a true “spiritual paradigm” for business and human society at large. The study also elaborates on the characteristics of the post-digital era and the nature of SDOs.

Workplace spirituality has been a research topic for years but has never gained sufficient momentum. The Covid-19 global pandemic has made workplace spirituality a more pertinent issue on corporate agendas. Therefore, this paper provides the theoretical foundation to embed workplace spirituality in contemporary management thoughts and practices.

This study reviews the extent of application of artificial intelligence (AI) tools in the construction industry.

A thorough literature review (based on 165 articles) was conducted using Elsevier's Scopus due to its simplicity and as it encapsulates an extensive variety of databases to identify the literature related to the scope of the present study.

The following items were extracted: type of AI tools used, the major purpose of application, the geographical location where the study was conducted and the distribution of studies in terms of the journals they are published by. Based on the review results, the disciplines the AI tools have been used for were classified into eight major areas, such as geotechnical engineering, project management, energy, hydrology, environment and transportation, while construction materials and structural engineering. ANN has been a widely used tool, while the researchers have also used other AI tools, which shows efforts of exploring other tools for better modelling abilities. There is also clear evidence of that studies are now growing from applying a single AI tool to applying hybrid ones to create a comparison and showcase which tool provides a better result in an apple-to-apple scenario.

The findings can be used, not only by the researchers interested in the application of AI tools in construction, but also by the industry practitioners, who are keen to further understand and explore the applications of AI tools in the field.

There are no studies to date which serves as the center point to learn about the different AI tools available and their level of application in different fields of AEC. The study sheds light on various studies, which have used AI in hybrid/evolutionary systems to develop effective and accurate predictive models, to offer researchers and model developers more tools to choose from.

Transfer relations represent analytical solutions of the linear theory of circular arches, relating each one of the kinematic and static variables at an arbitrary cross-section to the kinematic and static variables at the initial cross-section. The purpose of this paper is to demonstrate the significance of the transfer relations for structural analysis by means of three examples taken from civil engineering.

The first example refers to an arch bridge, the second one to the vault of a metro station and the third one to a real-scale test of a segmental tunnel ring.

The main conclusions drawn from these three examples are as follows: increasing the number of hangers/columns of the investigated arch bridge entails a reduction of the maximum bending moment of the arch, allowing it to approach, as much as possible, the desired thrust-line behavior; compared to the conventional in situ cast method, a combined precast and in situ cast method results in a decrease of the maximum bending moment of an element of the vault of the studied underground station by 46%; and the local behavior of the joints governs both the structural convergences and the bearing capacity of the tested segmental tunnel ring.

The three examples underline that the transfer relations significantly facilitate computer-aided engineering of circular arch structures, including arch bridges, vaults of metro stations and segmental tunnel rings.

This review aims to give a critical view of the wheel/rail high frequency vibration-induced vibration fatigue in railway bogie.

Vibration fatigue of railway bogie arising from the wheel/rail high frequency vibration has become the main concern of railway operators. Previous reviews usually focused on the formation mechanism of wheel/rail high frequency vibration. This paper thus gives a critical review of the vibration fatigue of railway bogie owing to the short-pitch irregularities-induced high frequency vibration, including a brief introduction of short-pitch irregularities, associated high frequency vibration in railway bogie, typical vibration fatigue failure cases of railway bogie and methodologies used for the assessment of vibration fatigue and research gaps.

The results showed that the resulting excitation frequencies of short-pitch irregularity vary substantially due to different track types and formation mechanisms. The axle box-mounted components are much more vulnerable to vibration fatigue compared with other components. The wheel polygonal wear and rail corrugation-induced high frequency vibration is the main driving force of fatigue failure, and the fatigue crack usually initiates from the defect of the weld seam. Vibration spectrum for attachments of railway bogie defined in the standard underestimates the vibration level arising from the short-pitch irregularities. The current investigations on vibration fatigue mainly focus on the methods to improve the accuracy of fatigue damage assessment, and a systematical design method for vibration fatigue remains a huge gap to improve the survival probability when the rail vehicle is subjected to vibration fatigue.

The research can facilitate the development of a new methodology to improve the fatigue life of railway vehicles when subjected to wheel/rail high frequency vibration.