Search Results (184)

Based on urban subway foundation pit projects in typical limestone areas, this paper employs 3DEC numerical simulation to investigate the effects of the thickness and burial depth of weak interlayers on the deformation characteristics and stability of the dip slope and anti-dip sides of rock foundation pits. The results reveal asymmetric deformation responses between the two slope types. The anti-dip side undergoes bending and toppling deformation; the displacement within the weak interlayer is greater than that of the overlying rock mass, and the spatial position of the weak interlayer governs the maximum deformation of the anti-dip side. In comparison, the thickness and burial depth of the weak interlayer exert a significant influence on the horizontal displacement of the dip slope side. Two quantitative critical thresholds are identified: (1) an interlayer thickness threshold—when t ≥ 4 m, the extrusion displacement of the weak interlayer is distinctly larger than that of the adjacent hard rock, while t ≤ 3 m shows no obvious displacement difference due to the clamping effect of surrounding rock—and (2) a burial depth threshold—slope displacement rises sharply when interlayer burial depth reaches 22.66~26.15 m, while shallow-buried interlayers (12.20~19.18 m) only cause limited deformation. Additionally, the existence of weak interlayers leads to substantially larger displacement in the upper hard rock stratum relative to the lower stratum. These findings provide a reliable reference for the supporting optimization and stability design of rock foundation pits. Full article

The localized high hydraulic gradient at the bottom of concrete cutoff walls in deep overburden foundations poses a significant seepage failure risk. This stability is heavily influenced by the high-stress state, a critical factor often overlooked in conventional evaluations. Taking a specific engineering project as the research background, this study investigates the seepage stability of gravelly medium-coarse sand by simulating the coefficient of earth pressure at rest (K₀) condition. A comprehensive series of triaxial seepage tests was conducted across burial depths from 120 m to 260 m, supplemented by conventional zero-stress permeability tests as a baseline. The results indicate that the seepage failure mode is characterized by overall soil flow. For soil deeply buried at the wall bottom, the risk of seepage failure is relatively low, provided there are no significant geological defects or internal seepage outlets nearby. Compared to conventional tests, the K₀ stress condition significantly increases the failure gradient and reduces the permeability coefficient. Under the same gradation, variations in burial depth have a negligible influence on these parameters. However, at the same burial depth, particle gradation has a major effect; the mean envelope line is the most sensitive to stress, followed by the upper and lower envelope lines. Based on these findings, an allowable hydraulic gradient of 3.0 is proposed—approximately five times the traditional design value (0.6–0.65). This study provides a critical scientific basis for the seepage-control design and stability assessment of high dams on deep overburden foundations. Full article

The article deals with non-destructive methodologies for assessing and preventing corrosion of polymer-coated underground pipelines, advanced corrosion-barrier coating systems based on extruded three-layer high-density polyethylene (3LPE), corrosion control strategies for buried oil, gas, and water transmission infrastructures, and mechanisms and engineering approaches for corrosion prevention and mitigation. The quality assurance of newly polymer-coated underground pipelines, following construction (installation and backfilling), is vital for evaluating the polymer coating quality state and the efficiency of passive anti-corrosion protection, aimed at reducing corrosion risks and prolonging the pipeline’s service life. The evaluation relies on the coating average specific electrical resistance and the presence of coating defects (number, total area, and distribution) of inspected pipeline sections. In this study, based on extensive real data obtained from testing of newly installed underground water and oil/gas pipeline networks (60 projects with a total pipeline length of 260 km) with various technical characteristics, Drainage Test and DCVG (Direct Current Voltage Gradient) complementary non-destructive indirect methods have been investigated to determine the quality level and identify the location and severity of defects in polyolefin (polyethylene) coatings. The novel concepts and criteria were defined: the quantitative criteria for average specific electrical resistance are established; in addition, a new parameter related to the specific coating defects ratio is introduced, which has been shown to correlate with the criteria for the average specific electrical resistance of the polymer coating and consumed electrical current; finally, following DCVG measurements of the 3LPE coating system, a novel degree of relative defect sizes (%IR) for repairs has been suggested. The innovative and comprehensive approach can support the efforts of regulatory quality assurance, design, maintenance, safety, and research communities to ensure the long-term integrity and sustainability of underground polymer-coated steel pipelines. Full article

Earth–Air Heat Exchangers (EAHEs) are passive systems that use the thermal interaction between air and soil along buried ducts to moderate supply air temperature, thereby lowering building energy consumption and improving indoor comfort conditions. This device has been employed in several countries and under diverse climatic characteristics. The integration of EAHE systems with bioclimatic design strategies contributes to improved building energy performance and more efficient use of thermal resources. This study aims to computationally investigate the thermoenergetic performance of EAHE system, for both cooling and heating purposes, installed in Social Housing (SH) across different Brazilian bioclimatic zones, and to propose strategies that improve the energy efficiency of these built environments. The study involves the validation and verification of a computational model and the thermoenergetic assessments of an SH unit, investigating different solar orientations and the installation of EAHE. These evaluations are performed via dynamic simulations conducted with the EnergyPlus software. The results show that the installation of the EAHE system coupled to the SH improves the thermoenergetic performance of the indoor environment, mainly by enhancing thermal comfort across different Brazilian bioclimatic zones (BZ). In BZ2R, the EAHE increased the annual PHFT by 4.5%, corresponding to seventeen additional days per year within the acceptable operative temperature range. The highest monthly improvement was observed in BZ1M, where the PHFT increased by 14.3% in January, equivalent to more than four additional days of thermal comfort in that month. The system proved to be more effective in zones 1M, 2R, 3B, and 4B, particularly in climates with lower annual average dry-bulb temperatures. Regarding energy performance, the EAHE showed benefits in specific months and conditions, indicating that its feasibility should be assessed through monthly thermoenergetic analyses rather than only annual indicators. This work provides validated and verified references and parameters for future projects and contributes to the state of the art in this field, as there are still few studies evaluating EAHE systems integrated into buildings using this software, despite its widespread use in building performance analysis. Full article

Traditional methods for the structural analysis of tunnel linings are often hampered by complexity and significant time consumption, creating the need for a more efficient analysis workflow. To address this issue, this study develops an application oriented surrogate modeling framework centered on parametric design-driven MINN. The framework of PD-driven MINN leverages parametric design to systematically generate a comprehensive dataset of 2000 parameter groups from FEA, providing a robust foundation for model training. Meanwhile, the MINN architecture is tailored to process these diverse inputs, effectively capturing complex parameter interactions while balancing computational speed and modeling accuracy. To validate the proposed strategy, the model’s predictions were rigorously compared against real-world engineering data from pre-buried sensor measurements in an actual transportation tunnel project. The results indicate the reliability of a parametric design-driven MINN surrogate model. A comparative analysis demonstrates its superior fitting performance and convergence over traditional artificial neural networks. This study demonstrates the practical value of adapting existing neural network techniques and integrating them with parametric design to support more efficient tunnel lining structural analysis. Full article

In this paper, we provide new insight into the Quaternary tectonics of the Floridia Graben (southeastern Sicily) and develop 3D geologic and ground-flow models of its subsurface. The Floridia Graben is a structural depression bounded by NW–SE trending normal faults and represents the main water reservoir that supplies the city of Siracusa (southeastern Sicily) and its countryside. The knowledge of the subsurface geology and neo-tectonic evolution of the Floridia Graben, as well as the spatial distribution of groundwater volumes is crucial for the management and protection of water resources. Within the government project of the new Italian geological cartography (ISPRA-CARG, Sheet N. 646 Siracusa), field and well data (both publicly available and newly acquired) have been collected and reinterpreted. NW–SE and NE–SW buried tectonic–structural features, inferred in the sub-surface of the graben, are consistent with the orientations of Quaternary faults diffusely observed inside and outside the investigated area. The Quaternary tectonic activity of bounding and buried faults has had a strong influence on the control of the morpho-structural pattern and, consequently, the groundwater flow of the Floridia Graben. The study allowed for the redefinition of the timing of these structures as well as their tectonic–structural control on the graben’s architecture and related water flow. The study represents a valuable tool for the better prediction of the spatial distribution of geologic and hydrogeologic volumes, thus enhancing the efficiency in the management and protection of natural resources. Full article

Eastern Thailand serves as a critical case study for the escalating tension between agricultural preservation and urban expansion, a dynamic recently intensified by the COVID-19 pandemic. This study addresses a pivotal research question: To what extent do emerging socio-economic realities, such as policy shifts, labor fluctuations, and climatic extremes, alter the spatiotemporal continuity of urban expansion? Employing a mixed-methods approach, we integrated multi-stakeholder insights with quantitative spatial modeling to simulate context-specific land use futures through 2030. Qualitative findings indicate that while COVID-19 accelerated agricultural modernization, evidenced by increased mechanization and e-commerce integration, these shifts have limited long-term impact on land use patterns. Instead, regional policy, climate change, and technological innovation emerged as the primary drivers of landscape transformation. Quantitative simulations reveal that urban growth will concentrate in the western provinces bordering Bangkok and the southern coastal corridors of Chon Buri and Rayong. Crucially, across all scenarios, approximately 60% of new urban land is projected to be converted from existing croplands, followed by significant losses in natural forest cover. These results demonstrate that current growth-oriented policies may undermine regional food security and ecosystem services. This study provides a framework for balancing agricultural modernization with ecological preservation, offering essential evidence for developing the integrated, sustainability-focused land use frameworks required to meet 2030 development goals. Full article

Underground utilities form an essential part of urban infrastructure, yet their importance often becomes apparent only when service disruptions occur. Excavation activities for maintenance, relocation, or new construction carry considerable risks, including utility strikes, project delays, worker injuries, and even fatalities. These risks are largely driven by incomplete or inaccurate information about the location, depth, or material properties of buried utilities. To address this challenge, this study proposes a comprehensive Building Information Modeling (BIM)-based framework for managing underground utilities throughout their lifecycles. The framework is structured into five key stages: data acquisition, data processing, modeling, system application, and data updating. A highway project was used as a case study to validate the proposed approach. The study involved the integrated modeling and visualization of the highway corridor, underground gas pipelines, and overground high-voltage transmission pylons using Autodesk Civil 3D, InfraWorks, and Navisworks. The developed model and workflow were subsequently reviewed with the client department. Application of the framework to a 5 km highway corridor identified five utility-road conflict points (three subsurface gas pipeline intersections and two overground pylon encroachments) that were not detectable from existing 2D records. Expert review by the client department confirmed that the BIM-based visualization and 4D simulation improved construction planning clarity and supported proactive utility relocation decisions. By simplifying information workflows and enabling collaboration among stakeholders, the proposed framework demonstrates strong potential to improve excavation safety, enhance decision-making, and support the wider adoption of BIM for underground utility management. Full article

Deep-buried tunnels in urban environments require careful evaluation of their long-term interactions with the surrounding ground to ensure structural safety and sustainability. Taking the Beijing Eastern Sixth Ring Road renovation project as a case study, this research employs a fully coupled fluid–solid numerical approach to elucidate the long-term disturbance mechanisms associated with deep-buried shield tunneling. Specifically, the research quantifies spatio-temporal ground responses and characterizes the consolidation settlement mechanisms exacerbated by potential tunnel leakage. The results indicate that ground deformation is primarily governed by the intensity of tunnel leakage. When the waterproofing grade of the tunnel meets Grade I or II, leakage and surface settlement remain negligible. However, when a tunnel’s waterproofing grade deteriorates to Grade IV or lower, consolidation settlement increases significantly, becoming the dominant deformation mode. In addition, both the extent and severity of ground movement are highly sensitive to the geometrical boundaries of the strata and the relative depth of the tunnel. Larger permeable domains and deeper tunnels lead to wider pore pressure and stress disturbance zones, ultimately leading to more pronounced long-term settlement. Furthermore, soil permeability dictates the temporal evolution of the ground response, with poorly permeable layers exhibiting delayed fluid–solid re-equilibration. A critical threshold is observed when leakage rates align with or exceed the soil’s permeability, leading to a significant escalation in both the amplitude of subsidence and the time required to reach equilibrium. These findings offer valuable insights for the design, waterproofing, and long-term management of deep urban tunnels. Full article

To address the critical challenges of geological hazards, such as water and mud inrush, encountered during the construction of deep-buried tunnels in China, this study investigates the hydraulic properties of remolded mud-infill materials. A multi-scale approach, integrating indoor variable-head permeability tests with scanning electron microscopy (SEM), was employed to characterize the evolutionary patterns of the permeability coefficient (k). Specifically, the research evaluates the independent influences of moisture content, dry density, and confining pressure, alongside the synergistic coupling between dry density and hydration state. The results demonstrate the following: Under independent variable conditions, k exhibits a monotonic decline with increasing dry density and confining pressure while showing a positive correlation with moisture content, with the sensitivity varying significantly across different parameter regimes; under coupled effects, the permeability in both low- and high-moisture ranges manifests a distinct “increase–decrease–increase” fluctuation as dry density rises, reaching a local peak at 2.20 g/cm³. Notably, a relative minimum k (6.12 × 10⁻⁷ cm/s) is achieved at the optimum moisture content (5.8%); micro-mechanistic analysis reveals that low-moisture samples are characterized by randomized angular particles and well-developed interconnected macropore networks, facilitating higher k values. Conversely, high-moisture samples exhibit preferential plate-like stacking dominated by occluded micropores, resulting in a substantial reduction in hydraulic conductivity. This study elucidates the multi-factor coupling mechanism governing the seepage behavior of remolded mud, providing essential theoretical benchmarks for the prediction and mitigation of water–mud outburst disasters in deep underground engineering, thereby ensuring the structural stability and operational safety of tunnel projects. Full article

Resource-constrained IoT systems face a fundamental conflict between cryptographic security and energy efficiency, particularly in critical infrastructure monitoring requiring long-term autonomous operation. This study presents a hybrid framework integrating signal-adaptive compression with hardware-accelerated authenticated encryption to resolve this trade-off. The Dynamic Payload Compression with Selective Encryption framework classifies sensor data into three SNR regimes and applies adaptive compression strategies: 24.15-fold compression for low-SNR backgrounds, 1.77-fold for transitional states, and no compression for high-SNR leak detection events. Experimental validation using 2714 acoustic sensor samples demonstrates 5.91-fold average payload reduction with 100% detection accuracy. The integration with STM32L5 hardware AES acceleration reduces power–data correlation from 0.820 to 0.041, increasing differential power analysis attack complexity from 500 to over 221,000 required traces. Compression-induced timing variance provides additional side-channel masking, burying cryptographic signals beneath a 0.00009 signal-to-noise ratio. Projected on 19,200 mAh lithium thionyl chloride batteries, the system achieves 14-year operational lifetime under realistic duty cycles, exceeding industrial requirements for critical infrastructure protection while maintaining robust security against physical attacks. Full article

To explore the stress-bearing characteristics of the “inner tensioned steel ring–segment–surrounding rock” composite structure in TBM (Tunnel Boring Machine) pressurized water conveyance tunnels, a 3D refined finite element model for this composite structure was established, with the Class V surrounding rock section of the TBM pressurized water conveyance tunnel in the Rongjiang-Guanbu water diversion project selected as the research subject. The effects of the internal water pressure, surrounding rock type and tunnel burial depth on the mechanical properties of the composite structures are studied. The findings demonstrate that reinforcing the tunnel structure with an inner tensile steel ring can effectively constrain tunnel deformation, diminish the tensile stress of segments and the extent of tensile zones, and enhance the bearing capacity of the composite structure. Under the effect of internal water pressure, the compressive stress of segments, vertical deformation, joint opening degree, stress of connecting bolts, stress of the inner tension ring, and stress of anchor rods all exhibit a reduction compared to the scenario without internal water pressure. Under the combined action of external water–soil pressure and internal water pressure, variations in surrounding rock types lead to respective increases of 37.16%, 15.75%, and 15.12% in the stress of connecting bolts, segment joint misalignment, and anchor bolt stress. As the tunnel burial depth increases, the stress of connecting bolts and the vertical deformation of segment and the joint misalignment of the pipe segment increase by 140%, 107% and 60.61%, respectively. In addition, under the combined action of external water and soil pressure and internal water pressure, the load-sharing ratios of the surrounding rock, pipe segment, inner tension ring and anchor rod are 34.87%, 34.59%, 21.59% and 8.95%, respectively, and the load-sharing ratio of the inner tensioned ring is 85.80% higher than that observed in the absence of internal water pressure, indicating that internal water pressure effectively enhances the load-sharing performance of the inner tensioned steel ring. In the composite structure, the load-sharing ratio of surrounding rock decreases as the surrounding rock class increases (from Class III to Class V). Under the same load condition, the load-sharing ratio of Class III surrounding rock is 7.14% higher than that of Class V. As the tunnel burial depth increases, the inner tensioned steel ring and anchor rods function more prominently as reserve-bearing components. When the tunnel burial depth reaches 71 m, the load-sharing ratio of the inner tension steel ring and anchor rod increases by 19.91% and 55.72%, respectively, compared with that of the buried depth of 31 m. The research results can provide a theoretical reference for the lining design and late reinforcement measures of similar tunnel projects. Full article

This systematic review synthesizes passive and passive-first cooling strategies for greenhouses in hot–arid climates, organizing evidence across four domains: Airflow & Ventilation, Shading & Radiative Control, Thermal Storage & Ground Coupling, and Structural Design & Geometry. Drawing on the project corpus, we analyze 10–13 distinct techniques including ridge and side natural ventilation, windcatchers and solar chimneys, external shade nets, NIR-selective and transparent radiative-cooling films, and dynamic PV shading; earth-to-air heat exchangers (EAHE/GAHT), rock-bed sensible storage, phase-change materials (PCMs), and sunken or buried envelopes; as well as roof slope and shape, span number, and orientation. Across studies, cooling outcomes are reported as peak or daytime indoor air temperature reductions, defined relative either to outdoor conditions or to a control greenhouse, with the reference frame and temporal aggregation specified in the synthesis. Typical outcomes include ≈3–7 °C daytime reduction for optimized ventilation, ≈2–4 °C for shading and spectral covers while preserving PAR, ≈5–7 °C intake cooling for EAHE with winter pre-heating, and up to ≈14 °C peak attenuation for rock-bed storage under favorable conditions. Structural choices consistently amplify these effects by sustaining pressure head and limiting thermal heterogeneity. Performance is strongly context-dependent—governed by wind regime, diurnal amplitude, dust and UV exposure, and crop-specific light and temperature thresholds—and the most robust results arise from stacked, site-specific designs that combine skin-level radiative rejection, buoyancy-supportive geometry, and ground or latent buffering with minimal active backup. Smart controllers that modulate vents, shading, and targeted fogging or fans based on VPD or temperature differentials improve stability and reduce water and energy use by engaging actuation only when passive capacity is exceeded. We recommend standardized composite metrics encompassing temperature moderation, humidity stability, PAR availability, and water and energy use per unit yield to enable fair cross-study comparison, multi-season validation, and policy adoption. Collectively, the synthesized techniques provide a practical palette for improved greenhouse climate management under hot and arid conditions. Full article

This article examines public preferences for a proposed West Coast submarine high-voltage direct current (HVDC) transmission network in South Korea, installed by trenching and burying the cables in the seabed, which is essential for facilitating renewable energy integration and ensuring a stable electricity supply to the Seoul Metropolitan Area. The purpose of this study is to estimate South Korean households’ willingness to pay (WTP) for the proposed West Coast submarine HVDC network using contingent valuation (CV), thereby assessing its social acceptability amid renewable energy integration challenges. Employing a CV survey with a nationally representative sample of 1000 households conducted from late May to late June 2025, the research applies the one-and-one-half-bound spike model to address zero WTP responses and incorporates socio-demographic covariates to account for preference heterogeneity. The analysis estimates an average monthly WTP of KRW 1832 (USD 1.33) per household for the HVDC infrastructure. Results demonstrate statistically significant public support for the submarine HVDC project despite its high capital investment and potential electricity rate increases. These findings underscore notable consumer acceptance and provide valuable welfare insights for policymakers, reinforcing the prioritization of this project within South Korea’s energy transition framework. This paper contributes to the field of energy infrastructure valuation by advancing methodological approaches and offering policy-relevant recommendations for sustainable grid expansion. Full article

The safety of the deep-buried, long tunnel at the active fault is a crucial issue in the Yangtze River to Hanjiang River Water Diversion Project, which crosses the Tongcheng River Fault. This study presents the first systematic investigation into the behavior of large deep-buried water diversion tunnels crossing active faults. Based on an analysis of the geostress field, numerical simulations were conducted to evaluate the response of the lining without adaptive measures. Subsequently, a method for estimating hinged design parameters was proposed, and reasonable design values were determined. Furthermore, the effectiveness of the adaptive hinged structure in improving anti-dislocation performance was assessed using a self-developed evaluation framework for tunnel lining. The results show that (1) Geostresses include a 35° angle between horizontal principal stress and the tunnel axis, with horizontal stresses of 20 MPa (axial) and 21 MPa (perpendicular), and vertical stress of 18 MPa. (2) Without adaptive measures, tunnel deformation peaks in the fault zone, showing vault-floor convergence; maximum principal stresses and liner damage concentrate there. (3) The proposed hinge-type adaptive design suggests a 6 m segmented section length and 2–4 cm hinge width initially; sensitivity analysis recommends 6 m and 5 cm, respectively. (4) Adaptive measures reduce tensile stress in the fault zone, significantly mitigating deformation, stress, and liner damage, proving their efficacy in enhancing anti-fault-rupture performance. Full article