To reduce the instability risk of open‐pit mine slopes, a stability analysis model for open‐pit mine slopes considering simplified weighting and data fluctuations is studied. First, identify the factors influencing the stability of open‐pit mine slopes from five aspects: hydrogeological factors, engineering geological factors, mining process factors, environmental geological factors, and other influencing factors, and establish an indicator system for these influencing factors. Second, classify the stability of open‐pit mine slopes by comprehensively evaluating stability conditions and establishing classification criteria. Furthermore, the six‐scale interval scoring (SSIS) method is proposed to determine the weights of influencing factor indicators. Considering the interval fluctuation characteristics of influencing factor indicator data, an open‐pit mine slope stability analysis model is constructed based on the interval approximation method. Finally, based on this model, an analysis was conducted on the stability of Slope #1 at a large open‐pit mine. And it was concluded that the stability state of this section of the slope was at level P 3 . The comprehensive analysis results of the slope stability state and numerical simulation combined with on‐site investigation are basically consistent. The study demonstrates that the slope stability analysis model for open‐pit mines, which accounts for simplified weighting and data fluctuations, is reliable and capable of accurately determining slope stability.
This study presents a comprehensive investigation into the axial load-bearing capacity of welded high-strength steel (HSS) I-shaped sections subjected to concentric compressive loading. Advanced nonlinear finite element (FE) simulations incorporating experimentally measured geometric imperfections, welding-induced residual stresses, and nonlinear stress–strain behavior were developed and validated against previously reported experimental data covering a wide range of nominal yield stresses, cross-sectional dimensions, and member slenderness ratios. The FE models demonstrated excellent predictive capability, when compared with experimental results. The experimental results were also employed to evaluate the predictive performance of 11 major international design code provisions: ASCE 10-15, AISC 360-22, AASHTO LRFD (2024), SSRC Guide, Eurocode EN 1993-1-1, BS 5950-1, Russian SP 16.13330, Australian AS 4100, Indian IS 800, Chinese GB 50017-2017, and the Japanese Code through comprehensive statistical analyses. The code predicted capacities showed some variations, with correlation coefficients between 0.92 and 0.95. IS 800, Eurocode 3, and the Chinese code were most conservative, underpredicting capacities by 20%–25%; AISC 360-22, AASHTO, BS 5950, AS 4100, the Japanese code, and the Russian code were moderately conservative (9%–15%); ASCE 10-15 and SSRC showed the closest agreement with test results. Classification of specimens by slenderness and steel grade revealed that prediction accuracy is governed primarily by each code’s inherent design philosophy rather than member slenderness, while conservatism increases systematically with steel grade, from conventional HSS (Q420–Q460) to advanced HSS (Q550–Q960). Compactness checks confirmed all specimens were non-slender, indicating that capacity discrepancies arise from global buckling behavior rather than local plate element instability. These findings provide a unified, cross-code benchmarking framework and practical guidance for engineers selecting design provisions for welded HSS I-section columns.
Asphalt pavements in cold regions are prone to early surface‐layer degradation under extreme temperatures, frequent freeze–thaw cycles, and strong UV radiation. Such degradation can alter material properties, induce stress redistribution within pavement structures, and increase fatigue risk. To quantify the transmission effect of surface‐layer degradation on structural response and fatigue performance, this study tested the strength and modulus of AC‐13 asphalt mixtures after freeze–thaw cycles and UV aging at a reference temperature of 20°C. The measured material parameters were then incorporated into a dual‐modulus mechanical model to calculate pavement load responses. Bottom tensile stress and equivalent stress‐strength ratio were used as structural indicators to evaluate comparative fatigue‐life changes under different early‐service degradation states. The results show that freeze–thaw cycles significantly deteriorate mixture properties, with the uniaxial compression (UC) modulus decreasing by 46% after 24 cycles, whereas UV aging increases mixture strength and modulus during the early aging stage. Under the investigated conditioning levels and modeling assumptions, the numerical results show that freeze–thaw‐induced surface‐layer property changes cause stress redistribution and reduce the calculated fatigue‐life indicators of the upper surface and subbase layers. Although UV aging increases the stiffness of the surface layer and alters the modeled stress distribution, sequential UV–freeze–thaw (UV–FT) conditioning still reduces the comparative fatigue‐life indicators of the critical structural layers. This study provides a material‐to‐structure analysis framework for evaluating early degradation effects and fatigue‐risk evolution of asphalt pavements in cold regions.
The California bearing ratio (CBR) is a key parameter for flexible pavement and airfield runway design; however, its laboratory determination is labor-intensive, time-consuming, and costly. This study developed a predictive model for soaked CBR values using compaction characteristics and some index properties of soil to provide a cost-effective estimation tool for subgrade soils in Seka Town, Ethiopia. A total of 39 fine-grained soil samples were collected from an ongoing roadway construction project. Thirty samples were used for model calibration, while the remaining nine samples were reserved for internal validation. Laboratory testing was conducted in accordance with ASTM and American Association of State Highway and Transportation Officials (AASHTO) standards to determine index properties, including percentage passing sieve No. 200, liquid limit (LL), plastic limit (PL), and plasticity index (PI) as well as compaction characteristics such as maximum dry density (MDD) and optimum moisture content (OMC) and CBR values. The investigated soils were predominantly classified as MH and ML under the Unified Soil Classification System (USCS) and A-7-5 and A-7-6 under the AASHTO classification system. Simple and multiple linear regression (MLR) analyses were performed using SPSS software. Among the developed models, the MLR equation, CBR = −12.124 − 0.077LL − 0.178OMC + 20.37MDD, demonstrated a strong correlation (adjusted R2 = 0.887) and the best predictive performance with low error metrics (MAE = 0.511, MAPE = 6.84%, and RMSE = 0.66). Internal validation confirmed good predictive accuracy, with an average variation of 3.64%. However, external validation using a secondary dataset resulted in a significant average variation with a low correlation (R2 = 0.381) and relatively high error metrics (MAE = 4.471, MAPE = 43.65% and RMSE = 4.76), indicating poor generalizability across different geographic regions. Therefore, the developed model should be considered preliminary and locally applicable to soils with characteristics similar to those of the study area. Further validation using larger, multiregion datasets and advanced modeling approaches is recommended before broader practical engineering application.
Chloride-induced deterioration compromises the seismic performance of reinforced concrete (RC) bridge piers, whereas the mechanical effectiveness of ultrahigh-performance concrete (UHPC) jacketing across different deterioration states remains insufficiently quantified. This study presents a fiber-section numerical framework to evaluate the cyclic response of UHPC-retrofitted rectangular RC bridge piers. Component-level validation against an uncorroded UHPC–RC composite column and corroded circular RC bridge piers produced peak-load errors of 3.03%–12.11% and captured the principal hysteretic trends. Parametric analyses considered jacket thicknesses of 30–50 mm, nominal UHPC compressive strengths of 100–150 MPa, service times from 45 years (T45) to 85 years (T85), and horizontal loading orientations from 0° to 90°. During 85 years, the normalized surviving residual yield force (SRYF) and peak force of the pier decreased by 23.3% and 18.7%, respectively. At 55 years and under, with a loading angle of 0°, increasing jacket thickness from 30 to 40 mm and nominal UHPC strength from 100 to 150 MPa increased the stiffness at 18.75 mm by 7.5% and 11.0%, respectively. Loading orientation produced pronounced nonmonotonic variations in cumulative energy dissipation. At the final plotted point, the value under 90° loading was 53.7% higher than that under 0° loading. In contrast, the value under 75° loading was 84.3% lower. The findings support a condition-based retrofit assessment that jointly considers the existing deterioration state, required jacket contribution, and direction-dependent seismic demand. Because the service-life cases represent independently assigned deterioration states, the results quantify the mechanical contribution of UHPC jacketing but do not demonstrate reduced chloride ingress or postretrofit corrosion rates.
