Municipal solid waste (MSW) is increasing rapidly, requiring more efficient and financially sustainable waste management systems. In Vietnam, MSW collection and treatment are still largely financed through flat household fees that are weakly linked to actual waste generation and depend heavily on public subsidies. This study applies a Full Cost Accounting (FCA) approach to design MSW tariffs for a ward in Da Nang City under three pricing scenarios: per capita/ household, weight based, and volume based. Excluding government subsidies, the estimated tariffs are 38,380 VND per capita per month (238,835 VND per household per month), 1,005 VND/kg, and 302 VND/L, respectively, all substantially higher than the current flat fee of 30,000 VND per household per month. The findings demonstrate FCA’s value in supporting the implementation of Pay-As-You-Throw (PAYT) schemes in Da Nang and other Vietnamese cities.
Interfacial cracks between dissimilar materials represent a critical failure mechanism in layered structural systems such as coatings, composite laminates, and micro-structured materials. However, classical elasticity theory cannot adequately capture the size-dependent behavior observed at micro- and nano-scales. This study investigates a pre-existing interfacial crack in a multilayered elastic medium using couple-stress elasticity and the displacement discontinuity method. The crack is modeled as a prescribed normal opening displacement discontinuity along the interface between two bonded layers resting on an elastic half-plane. The corresponding reaction tractions, stress fields, and couple-stress components are determined using Fourier transform techniques and Gauss-Legendre quadrature. The numerical results indicate that the material length-scale parameter and stiffness mismatch significantly influence the near-tip reaction stress field. For a prescribed crack opening, couple-stress effects enhance the microstructural resistance near the crack tip, highlighting the importance of size-dependent modeling in the analysis of layered interfacial fracture problems.
This study evaluates the accessibility of public bus stops in Da Nang's city center to examine the alignment between spatial distribution and actual user demand within the context of promoting a shift toward public transit. Utilizing GIS spatial distribution analysis (within a 300–500m radius) combined with user surveys, the results indicate that current accessibility remains limited, particularly within the alleyways of older residential areas. Regression analysis identifies that 'Roadside Amenities' (40.8%) and 'Accessibility' (30.4%) are the key factors determining passenger satisfaction. Consequently, the study proposes a 300–500m threshold (equivalent to a 5–10 minute walk) as the optimal service radius, while providing a practical basis for improving pedestrian infrastructure and "first-mile/last-mile" connectivity for the bus system in Da Nang.
This paper presents a finite element (FE) analysis of the flexural behavior of a semi-precast RC-UHPC panel during the construction stage. The panel consists of a prefabricated assembly comprising a bottom ultra-high-performance concrete (UHPC) layer, an expanded polystyrene (EPS) lightweight concrete core, and a steel truss mesh. The FE model employs flat triangular shell elements for the concrete layers and 3D bar elements for the steel truss, implemented using the CALFEM-Python framework. The model is validated against experimental data from the literature. A parametric study investigates the effects of the UHPC and EPS thicknesses as well as steel reinforcement diameters on panel deflection under self-weight and construction load. Results show that the EPS thickness is the dominant parameter governing flexural stiffness, while reinforcement diameter has a comparatively minor influence. Specific configurations satisfying practical deflection limits are identified, providing design guidance for this emerging slab typology in the construction phase.
Reliable precipitation data are critical for rainfall–runoff modeling and flood forecasting, yet rain gauge networks remain sparse in many developing regions. This study evaluates the suitability of three near-real-time satellite precipitation products—GSMaP-NRT, GPM-IMERG Early Run, and PERSIANN PDIR-Now—for forecasting reservoir inflow to the Ta Trach watershed in central Vietnam. A linear scaling bias-correction method was applied to reduce systematic errors before using the datasets as inputs to the HEC-HMS hydrological model. Performance was assessed using the Nash–Sutcliffe efficiency (NSE), coefficient of determination (R²), and relative volume error (RVE). Bias correction significantly improved rainfall estimates and streamflow simulations for all products. Among them, GPM-IMERG Early Run achieved the highest accuracy, with NSE = 0.85, R² = 0.84, and RVE = 4.95%. These findings demonstrate that bias-corrected GPM-IMERG Early Run provides reliable rainfall forcing for operational reservoir inflow forecasting and supports flood management in data-scarce basins.
This paper presents a workflow for the optimization of the shape of composite shells, where the shell model is parameterized by Splines. To achieve this, Gmsh API is used to establish the shell geometry using Splines passing through control points, where the coordinates of these points serve as the design variables. A self-developed module ‘geometry.py’ is built to ease the modeling task. The CALFEM-Python toolbox, supplemented with the CS-DSG3-A planar triangular shell element, is used as a tool for analyzing shell behavior depending on the geometry from Gmsh. The optimal shell shape is automatically sought through an improved differential evolution optimization framework. The entire optimization workflow is applied to isotropic and laminated composite shell models and evaluated.
Heavy rainfall across Central Vietnam in 2025 highlights the increasing intensity of extreme precipitation and the need for reliable regional climate projections. Although CMIP6 global climate models have improved climate simulations, their coarse spatial resolution limits basin-scale applications. This study uses high-resolution (10km) downscaled CMIP6-VN projections from 19 CMIP6 models to assess future rainfall, temperature, and hydrological changes in the Vu Gia Thu Bon River basin during 1985–2099 under four SSP scenarios (SSP1–2.6, SSP2–4.5, SSP3–7.0, and SSP5–8.5). Mean annual precipitation is projected to increase under all scenarios, reaching up to 6.7% above the historical baseline (1985–2014). Although rainfall and flood-season runoff increase, streamflow responses are substantially moderated by reservoir regulation, emphasizing the critical role of reservoir operations in future water management. These findings demonstrate the value of high-resolution climate projections for reducing uncertainty in hydrological impact assessments and supporting climate adaptation and water resources planning in regulated river basin.
Development, shaping children's learning, behavior, and social interactions. This paper establishes a theoretical framework linking preschool children's EI with kindergarten architectural design. In response to the growing emphasis on holistic education in Ho Chi Minh City (HCMC), the study synthesizes key EI theories (Mayer & Salovey; Goleman) and educational architecture principles. The proposed framework suggests that the physical environment of public kindergartens - including spatial layout, landscape, color, natural lighting, and functional spaces - can directly and indirectly influence four core EI components: Perceiving, Understanding, Managing, and Using Emotions. Based on these findings, the paper provides theoretical guidance for designing and renovating kindergarten environments that better support children's emotional development. The proposed framework contributes to integrating educational psychology and architectural design, thereby promoting higher-quality, child-centered early childhood education.
This study presents a nonlinear dynamic OpenSees framework for investigating the seismic progressive collapse response of three-dimensional reinforced concrete frames subjected to first-storey corner-column loss. The model incorporates material and geometric nonlinearities, distributed plasticity, rigid diaphragm constraints, and spatial force redistribution while maintaining computational efficiency for nonlinear time-history analysis. Two configurations, namely an intact frame and an initially damaged frame, were analyzed under earthquake ground motion. The results show that corner-column loss significantly increases compressive axial-force demand in the adjacent column, whereas the corresponding shear and bending moment responses increase only moderately. In the beam above the removed column, the response changes from slight compression to tensile axial force, while the bending moment decreases by approximately 50%, indicating a transition toward an axial tension-dominated catenary-like mechanism. The damaged frame also develops substantially larger lateral displacement demand, with peak roof displacement increasing by approximately 275% compared with the intact configuration.
The rapid growth of vehicle ownership in Vietnam has generated approximately 400,000 metric tons of waste tires annually, most of which are still disposed of through landfilling or incineration, exerting substantial environmental pressure. Within the sustainable development context, recycling waste tires into construction materials represents a promising resource recovery pathway. This study assesses the feasibility of incorporating recycled rubber into construction materials through a systematic literature review and field surveys at 20 tire facilities in Hanoi. Results indicate that replacing 5%-20% of concrete aggregate with recycled rubber improves impact absorption, acoustic insulation, and flexibility, though compressive strength tends to decline. The current collection and processing system remains fragmented, dominated by small-scale operators, with no established value chain linking waste tire flows to the construction sector. Technical standards and targeted policy instruments are needed to enable large-scale adoption and advance circular economy practices in Vietnam's waste management and construction sectors.
Indoor environmental quality during the operational phase of residential buildings plays a critical role in ensuring long-term occupant health and comfort. As part of the CAMaRSEC research project, a year-long measurement campaign of indoor microclimate conditions was conducted in 49 apartment units located within 15 high-rise residential buildings in Vietnam. Key parameters examined included temperature, relative humidity, indoor CO₂ concentrations, window orientation, and floor level. Apartments situated on lower floors and higher floors with naturally ventilated living rooms were selected to assess and compare indoor environmental quality by analysing thermal–humidity conditions, bioclimatic comfort, and temporal variations across units. Results reveal small differences in indoor microclimate conditions between low-rise and high-rise units. The high-rise units also show slightly higher indoor CO₂ concentrations due to prolonged periods of door-closing and tight seals. Based on these findings, the study proposes targeted recommendations aimed at improving indoor air quality.
The construction sector is increasingly exploring smart contracts (SCs) to resolve persistent operational challenges, such as payment delays and disputes. This study systematically analyzes SC and Distributed Ledger Technology (DLT) deployments globally and in Vietnam, identifying key legal, technical, and organizational constraints hindering domestic adoption. To bridge these gaps, a five-step implementation framework tailored to Vietnam's institutional and market conditions is proposed. The framework emphasizes incremental adaptation using regulatory sandboxes, a hybrid architecture integrated with Building Information Modeling (BIM), and fiat-based payment mechanisms. The findings highlight that successful adoption depends primarily on institutional readiness and regulatory alignment rather than the technology itself, advocating a phased approach aligned with local industry capabilities.
Geocell reinforcement has been increasingly applied in transportation infrastructure to improve the stability and serviceability of road embankments constructed on weak subgrades. The load transfer mechanism in geocell–soil systems involves complex interactions between soil confinement, lateral restraint, and membrane effects, which makes the design process challenging using conventional empirical approaches. This study presents a numerical and data-driven framework to investigate the performance of geocell-reinforced embankments subjected to static loading. Finite element simulations were conducted, considering variations in geocell location, geocell height, and distributed load. The simulations are automated through the PLAXIS Python API to generate a comprehensive dataset of embankment responses. A predictive model is then developed using Gene Expression Programming to estimate the settlement of reinforced embankments. A parametric study is subsequently performed to determine effective design configurations. The proposed framework provides a practical tool for improving the reliability and efficiency of geocell-reinforced embankment design.
The construction sector is a major consumer of natural resources and a significant source of emissions, making the transition toward a circular economy (CE) essential for sustainable development. Although Vietnam has introduced key policy commitments, including the Green Growth Strategy 2021–2030 and the Net Zero target by 2050, the implementation of CE principles in construction projects remains fragmented and lacks a unified assessment framework. This paper reviews the theoretical foundations of CE in the construction sector and examines the current state of application in Vietnam through literature review, policy analysis, and expert consultation. The findings indicate that existing practices mainly focus on waste management and recycled materials, while life-cycle-based design, supply chain integration, and governance mechanisms are insufficiently addressed. The study identifies critical research and practical gaps, providing a foundation for developing quantitative indicators and an assessment framework for CE implementation in construction projects in Vietnam.
The development of social housing is essential to meet the needs of low-income populations in rapidly urbanizing areas. However, in Vietnam, project licensing remains hindered by institutional, administrative, and technical barriers. This study examines key factors influencing the licensing process of social housing projects in Binh Duong Province using a mixed-method approach, including literature review, expert consultation, and survey data from 129 professionals. Five main factor groups are identified: stakeholder coordination, legal framework, technical infrastructure, land-use planning, and developer capacity. The results show that governance-related factors, especially stakeholder coordination and legal systems, have a stronger impact on licensing efficiency than technical and financial aspects. The study proposes policy recommendations focusing on institutional reform, improved coordination, and planning alignment, contributing practical insights for policymakers to accelerate social housing development in Vietnam and similar contexts.
This study develops a data-driven framework using Extreme Gradient Boosting (XGBoost) to predict the Indirect Tensile Strength (ITS) of cement-treated clayey soils. Using 180 specimens with five input variables - cement content, curing time, curing temperature, plasticity index, and compaction energy - the model was trained (80%) and tested (20%), achieving strong accuracy (training R²=0.932, RMSE=55.41 kPa; testing R²=0.922, RMSE=81.98 kPa). SHapley Additive exPlanations (SHAP) analysis was applied for interpretability, showing cement content (39.3%) and curing time (30.1%) as the dominant predictors, followed by plasticity index (12.9%), while compaction energy (9.1%) and curing temperature (8.6%) had minor influence. K-means clustering combined with SHAP waterfall plots identified five distinct strength-development behavior groups, offering mechanistic insight into ITS variability. Overall, the XGBoost-SHAP framework proves to be a robust, interpretable tool for performance-based design and mixture optimization of cement-treated soils in infrastructure applications.
This study investigates the determinants of multi-dimensional Building Information Modeling (BIM-nD) adoption and its relationship with organizational performance among construction-related firms in Da Nang, Vietnam. An analytical framework integrating the Technology–Organization–Environment (TOE) framework and BIM maturity concepts was developed to conceptualize BIM adoption as a progressive capability-building process. Survey data from 102 firms were analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM) with bootstrapping. The results show that human competency is the strongest positive driver of BIM-nD adoption, whereas technological capability and external pressure exert significant negative effects. Organizational readiness and cost–benefit feasibility show no significant influence. BIM-nD adoption is also negatively associated with organizational performance, indicating short-term transitional challenges. The findings highlight the need to align human capability, organizational processes, and institutional support to enable effective BIM-nD implementation.
Rain–wind-induced vibration (RWIV) may produce large-amplitude, low-frequency oscillations in stay cables under combined wind and rainfall. This study presents a simplified analytical framework for estimating RWIV while explicitly considering axial pretension, bending stiffness, cable geometry, structural damping, and rivulet-induced aerodynamic effects. Based on quasi-steady galloping theory, the aerodynamic force is formulated by incorporating the initial position and harmonic motion of a water rivulet. The governing equation of a tensioned cable is solved using modal decomposition. Parametric analyses show that the predicted vibration amplitude increases with cable length and diameter, whereas greater axial pretension and natural frequency reduce the response. Bending stiffness has only a minor influence within the investigated range, confirming the tension-dominated behavior of slender stay cables. Application to an assumed cable-stayed bridge demonstrates that considerable RWIV may occur under unfavorable wind–rain conditions and highlights the need to consider cable dynamic properties in preliminary vibration assessment.
Fiber-reinforced polymer (FRP)-reinforced concrete beams have increasingly applied in construction. Accurate prediction of shear strength in FRP-reinforced concrete beams with FRP stirrups is essential for safe and efficient structural design. This study aims to improve prediction accuracy by developing an enhanced support vector regression (SVR) model with the aid of an optimization algorithm, and a reliable dataset was evaluated using a 10-fold cross-validation approach. The proposed model achieved strong predictive capability with low error values. The enhanced SVR model with 200 wolves and 100 iterations provides the best performance, with RMSE, MAE, and MAPE values of 28.14kN, 19.27kN, and 15.40%, respectively, along with a correlation coefficient of 0.955. Furthermore, the optimized models outperformed conventional SVR models with different kernel functions. These findings indicate that the enhanced SVR approach is a reliable and effective tool for predicting shear strength, thereby supporting improved structural analysis and design in engineering practice.
Unconfined compressive strength (UCS) and elastic modulus (E₅₀) are key parameters governing the load-bearing capacity and deformation behavior of stabilized soft soils. This study investigated the effect of NaCl salinity on clayey soil stabilized with a cement–fly ash–lime binder system. Two experimental schemes were conducted. In Scheme 1, cement and fly ash contents were fixed at 20% and 30% of dry soil weight, respectively, while lime content varied from 2% to 6%. In Scheme 2, NaCl contents of 1–4% were introduced into the corresponding mixtures. Specimens were cured under standard conditions and tested by unconfined compression after 7, 14, 28, and 56 days. The results were used to evaluate the influence of NaCl salinity on UCS and E₅₀, providing an experimental basis for mixture design and performance assessment of stabilized soft soils in saline environments.
