The article presents the development of tunnel infrastructure in the world. Then, the hazards occurring in fires occurring in underground rail transport are characterized and several incidents that have occurred are described. It is also noted that a large role in improving fire safety in tunnels is played by conclusions drawn from experience from incidents that have occurred and by predicting new threats and possibilities of preventing them. Despite equipping tunnels with increasingly modern safety systems, fires, accidents and disasters still occur, as is shown by the given number of fires in tunnels in German-speaking countries that occurred in the years 2013–2023. In addition, the article discusses the current EU requirements aimed at ensuring an optimal level of safety in tunnels in the most economical way. They were developed taking into account scenarios of the most probable events. Ensuring that residual risk is reduced to a low level requires combining all safety layers in the following order: prevention, mitigation, evacuation and rescue. It was also emphasized that the proper selection of non-metallic materials for the construction and equipment of rolling stock and tunnel infrastructure is an important element of effective fire protection. Nevertheless, the required systematic inspections of the condition of vehicle and tunnel equipment, as well as rescue operations exercises according to various scenarios provided for in the Tunnel Emergency Plan, play an important role.
The analytical models for calculating the longitudinal deformation of existing high-speed railway tunnels when a shield tunnel passes beneath them mostly consider the underlying soil as a homogeneous foundation and neglect the variability of the strata. Taking into account the inherent spatial variability of the strata parameters, this study constructs a new mechanical model for the shield tunnel passing beneath existing high-speed railway tunnels, considering the influence of spatial variability in foundation stiffness, and derives the corresponding finite element solution. Through engineering case studies, the reliability of the established mechanical model for the shield tunnel passing beneath existing high-speed railway tunnels is verified. A stochastic analysis method is used to analyze the longitudinal deformation and internal forces of existing high-speed railway tunnels caused by the shield tunnel passing construction. The research results indicate: (1) For single-line shield tunnel construction, once the stratum loss rate exceeds 0.36%, the probability of exceeding the standards rapidly increases. When the loss rate reaches 0.96%, the probability of high-speed railway tunnel deformation exceeding the standards is already at 97.5%. For double-line shield tunnel construction, once the stratum loss rate exceeds 0.18%, the probability of high-speed railway tunnel performance exceeding the standards rapidly increases, and the risk of shield tunnel passing construction sharply rises. (2) The stratum loss rate during single-line shield tunnel passing beneath high-speed railway tunnels should be kept within 0.36%, while for double-line shield tunnel passing, the loss rate should be controlled within 0.18%.
Rural landscape design and sustainable development are deeply interconnected, requiring a multifaceted approach that involves scientific design principles, effective resource management, and the active participation of diverse stakeholders. This paper provides a comprehensive examination of the relationship between rural landscape design and sustainable development, focusing on the integration of ecological preservation with sustainable resource utilization. Through a detailed analysis of theoretical foundations, current challenges, and strategic design interventions, this research highlights the socio-economic benefits that arise from well planned rural landscapes, including improved aesthetics, enhanced biodiversity, and increased resource efficiency. The findings emphasize the necessity of balancing environmental conservation with human activity to foster long-term rural resilience and sustainability. This study offers a valuable framework for policymakers, designers, and researchers, supporting future efforts to implement sustainable practices in rural landscape design. By advancing practical strategies and theoretical insights, this research contributes to the development of sustainable rural environments that harmonize ecological health with socio-economic growth, ensuring a sustainable future for rural communities.
Dams are among the largest structures constructed by human. Their disasters result in numerous casualties and large material losses. The statistical analysis of the reasons for dam disasters was carried out by the International Commission on Large Dams (ICOLD). The analysis included large dams, i.e. dams that are higher than 15 meters or taller than 5 meters and form a reservoir with a capacity of more than 3×106 m3. ICOLD’s study took into account dams built up to 1986 regardless of the type of construction and the material used. The hazard function h(t) and next, the reliability function R(t) were calculated based on that data, using the fitting of the power function in the initial mortality period and a constant function in the useful operation period. The knowledge of the reliability function allowed for calculating the mean time to failure which was 112957 +/-12443 years. It was also demonstrated that in the operation period the annual dam failure ratio is 8.719×10−6 +/- 0.297×10−6. It is a value that is proximate to the recommendations of the U.S. Army Corps of Engineers which suggests the tolerance for the annual dam disaster risk not to exceed 10−6 failures per year for newly-constructed dams and 10−4 failures per year for already existing ones.
The subject of this paper is a simply supported functionally graded beam in three variants: (A) without rigid partitions, (B) with two rigid partitions, and (C) with four rigid partitions. The mechanical properties, specifically Young’s modulus, vary symmetrically in the depth direction of these beams. An analytical model of the beam, considering the individual nonlinear shear deformation of a plane cross-section, has been developed. Two differential equations of equilibrium for the beam, based on the principle of stationary total potential energy, were derived. This system of two equations was approximately solved for each beam variant, and the critical forces were determined with the distinguished shear effect coefficient. Detailed calculations were performed for exemplary beams with selected dimensionless sizes and mechanical properties. The results of these calculations are presented in tables and figures. The main goal of the research is to develop an analytical model of this beam and investigate the impact of rigid partitions placed within the beam on the critical force.
