Pultruded glass fiber-reinforced polymer (GFRP) hollow sections are attractive lightweight structural members but are often limited by low transverse stiffness and local instability under bending. This study investigates the flexural behavior of carbon fiber-reinforced polymer (CFRP)-strengthened cross-laminated pultruded GFRP (CL-GFRP) hollow beams and develops a stage-dependent analytical framework to describe stiffness evolution before and after damage initiation. Four CL-GFRP beam configurations (60 × 200 mm cross-section and 1450 mm length) with different layer orientations and strengthening conditions were tested under four-point bending (one specimen per configuration). The experimental results were interpreted using a transformed-section analytical model combined with a bilinear elastic–post-damage representation. Beams with the longitudinal GFRP layer located at the tensile face exhibited approximately 28% higher load resistance at a displacement of 60 mm (span/20) than those with the transverse layer in tension. CFRP strengthening increased load-carrying performance by approximately 35% and initial stiffness by 44–58%, while increasing post-damage stiffness and modifying damage progression. Analytical predictions showed good agreement with experimental responses within the elastic stage, while the post-damage response was represented qualitatively. The proposed framework provides insight into the interaction between layer orientation, CFRP strengthening, and damage evolution in a novel CL-GFRP structural system.
The construction industry remains one of the most hazardous sectors, with Indonesia reporting a persistent increase in work accidents. Ineffective documentation and sharing of project knowledge may cause the loss of critical lessons learned, limiting opportunities to improve safety performance. Although previous studies have emphasized knowledge management in construction safety, limited attention has been given to assessing Safety Knowledge Management (Safety-KM) as an interconnected system that integrates organizational enablers, KM processes, causal relationships, and priority weights. This study aims to analyze causal relationships and relative priorities of a Safety-KM assessment model to support safety performance improvement in large construction companies in Indonesia. DEMATEL was applied to identify the cause-and-effect relationships among Safety-KM sub-dimensions, while ANP was used to determine their priority weights based on expert judgments. The findings show that organizational culture is the strongest causal driver, while organizational strategy has the highest prominence. The KM process (KMP) dimension obtained a higher weight than the KM enabler (KME) dimension, with knowledge transfer emerging as the highest-weighted sub-dimension. This study contributes by providing a structured, context-specific, and improvement-oriented Safety-KM assessment model for the Indonesian construction industry.
Harbor basins located near river mouths are highly susceptible to sedimentation, resulting in substantial maintenance dredging costs. Underwater sills (UWSs) have been widely recognized as an effective measure for reducing sediment intrusion into harbor basins. However, conventional concrete UWSs are costly, while alternative materials such as geobags often require sloped configurations that may affect sediment-trapping performance. This study investigates the effectiveness of stepped-slope UWSs using the meshless numerical model DualSPHysics. The numerical model was validated against a physical-scale experiment to ensure its reliability in reproducing the relevant hydrodynamic processes. The results show that DualSPHysics accurately captures the flow field and the complex flow structures around the UWS. Hydrodynamic analyses indicate that stepped-slope geometry significantly influences local flow patterns and the net vertical settling velocity of suspended sediment particles. Milder slopes generally reduce sediment-trapping efficiency, whereas steeper slopes promote greater sediment retention upstream of the structure. The influence of slope angle is more pronounced for sediment with higher settling velocities and decreases as settling velocity becomes smaller. These findings provide practical guidance for the design of geobag-based UWSs for harbor sedimentation management.
This study evaluates the effectiveness of biopore absorption holes (BAH) and infiltration wells (IW) in reducing surface runoff and flood peak discharge in the Upper Maros Sub-Watershed, Indonesia, where mixed dryland agriculture dominates runoff generation. Field experiments were conducted on three representative land-cover classes, namely mixed dryland agriculture, secondary dryland forest, and shrubland, under baseline and post-intervention conditions. Rainfall intensity was estimated using the Mononobe method, infiltration was analyzed using the Horton model, surface runoff was estimated using the SCS-CN method, and peak discharge was simulated using the Nakayasu Synthetic Unit Hydrograph. The results showed a very strong runoff-peak discharge relationship, with a correlation coefficient of approximately 0.98, confirming that direct runoff is the dominant control of flood peaks. The infiltration-based interventions reduced mean surface runoff by about 57.6%, raised the infiltrated share of the combined runoff-infiltration volume to 66.41% under BAH and 69.29% under IW (23.37% at baseline), and decreased peak discharge by 55.8-59.4% across return periods from Q2 to Q100. The novelty of this study lies in integrating field-based infiltration interventions, land-cover-specific runoff analysis, and return-period flood simulation to demonstrate how low-cost nature-based solutions can weaken runoff sensitivity, enhance infiltration storage, and improve flood adaptation in tropical agricultural watersheds.
This study aims to investigate the impact response of reinforced concrete (RC) beams under equal-energy mass–velocity combinations and combined axial compression and to compare the predicted responses obtained from different concrete constitutive models. Nonlinear finite element simulations were performed using LS-DYNA and validated against a published drop-weight impact experiment. Three concrete models, KCC (*MAT_072R3), CSCM (*MAT_159), and Winfrith (*MAT_084), were compared using consistent fundamental material properties. Five mass–velocity combinations, ranging from 50 kg–13.72 m/s to 1000 kg–3.07 m/s at a constant impact energy of approximately 4.7 kJ, and axial compression ratios of 0–30% were investigated. The results show that equal impact energy does not produce equivalent structural responses. Low-mass/high-velocity impacts generated higher peak forces, shorter contact durations, and localized shear-dominated damage, whereas high-mass/low-velocity impacts produced greater displacement and flexural behavior. Increasing axial compression generally increased peak force while reducing displacement and contact duration. The three models predicted similar global responses but showed greater differences in local impact responses, particularly peak force and damage localization. The novelty of this study lies in systematically comparing the predictions of different concrete constitutive models under varying mass–velocity combinations and axial compression, providing guidance for constitutive-model selection in RC impact simulations.
