Stone arch bridge is an important type in the early bridge construction process because of its beautiful shape, material saving and economic rationality. However, stone material will deteriorate after long-term operation, which results in a decrease in strength and bearing capacity of stone arch bridge. The vehicle load is increasing at the same time. Therefore, accurate evaluation of bearing capacity of stone arch bridge is essential to ensure safety. In this article, a three-span open-spandrel stone arch bridge was taken as research object. Firstly, the bridge damages were investigated and analyzed in detail, and bridge service state was evaluated. Then, based on the evaluation results of disease damages and considering stone material deterioration, a refined finite element model of stone arch bridge was established to analyze bending moment, axial force, strain and deformation. Finally, static load test was carried out to test vertical deformation and stress of arch ring, horizontal displacement of pier, settlement of foundation and development of cracks. The results show that static load test is the most accurate method for evaluating bearing capacity of stone arch bridge. The evaluation accuracy of finite element model based on material correction is in the middle, and the evaluation accuracy of disease damage assessment is the worst. In practical work, bearing capacity of stone arch bridge can be evaluated by combining the three methods with high accuracy and comprehensive results.

Stay-cable forces in cable-stayed bridges without backstays may deviate from their design values during service, compromising safety and motivating regulation. This paper reports an in-service cable-force regulation project for the Jinzhou Bridge. A previous study characterized the in-service state of the bridge, determined its reasonable target state, and established and calibrated the corresponding finite element (FE) models; these results are adopted here as the research baseline. The maximum measured cable-force deviation was 78.95%, occurring in cable C2. The present study focuses on the stage-by-stage transition between the prescribed in-service and target states. Two opposite regulation sequences were evaluated stage by stage through FE simulations: Scheme A (from short cable C1 to long cable C9) and Scheme B (from long cable C9 to short cable C1), with the intermediate cable-force redistribution and the corresponding stress and deformation responses of the girder and tower examined at each stage. After satisfying the prescribed strength and alignment constraints, Scheme B was selected for field implementation because of its smaller process-induced cable-force fluctuations. The effect of the regulation sequence was particularly pronounced for the long cables C8 and C9, whose standard deviations under Scheme A were approximately 3.5 and 5 times those under Scheme B, respectively. Under Scheme B, the reductions applied to individual cables at their regulation stages ranged from 1856 to 14,646 kN. The required anchor-cup pullout control values ranged from 16.6 to 383.9 mm. The proposed framework advances the analysis from prescribed-state determination to constrained transition-path design and provides an implementable approach for in-service cable-force regulation of cable-stayed bridges without backstays.

This study evaluates molybdenum tailings (MT) as a substitute for limestone filler (LF) in asphalt mixtures. MT replaced LF on an equal volume basis. The replacement ratio ranged from 0% to 100%. The study conducted wheel tracking tests, three-point bending tests, immersion tests, and indirect tensile splitting tests. A representative MT100 mixture was selected for industrial CT scanning with VGStudio Max. The maximum entropy method was used for image segmentation. The method quantified aggregate, mastic, and air void phases. The results show that MT improved rutting resistance. Dynamic stability increased from 1071 passes/mm at 0% replacement to 1548 passes/mm at 100% replacement. The flexural stiffness modulus increased by 73.60% relative to the control at 100% MT replacement. Residual stability reached 86.92% at 100% replacement. CT observations of the 100% MT specimens showed an asphalt mastic phase surrounding the aggregate skeleton and dispersed air voids. The observed vertical nonuniformity was interpreted as a compaction-related structural feature associated with Marshall mold boundary effects. In conclusion, MT shows potential as an alternative mineral filler for improving asphalt mixture performance.