The scouring effect is widely acknowledged as a primary contributor to the weakening in the bearing performance of offshore piles; it often results in asymmetric scour patterns around the pile. To meticulously examine the impact of three-dimensional asymmetric local scour on the lateral bearing performance of a single pile, the Boussinesq solution is employed to determine the effective stress within the soil encompassing the pile, considering the presence of a three-dimensional asymmetric local scour hole. Utilizing the strain wedge model, the calculation method for the lateral bearing performance of a single pile under the condition of three-dimensional asymmetric local scour is established. The validity of this approach is established, and parameter analysis unveils the effect of varying sizes of three-dimensional asymmetric scour holes on the mechanical properties and displacement performance of a single pile. The analysis reveals that, as scouring dimensions around the pile escalate, the impact of scouring on single-pile lateral displacement and internal forces intensifies, leading to a decrease in the lateral bearing performance of a single pile. At a constant scour depth, the bottom area of the upstream scour hole significantly influences the displacement performance of a single pile. When the bottom length S_wb1 of the upstream scour hole grows by 1 time, 4 times, and 8 times, the lateral displacement of a single pile at a buried depth of 6 m is augmented by approximately 0.41%, 1.65%, and 2.06%, respectively. The simplified model obtained via the modified strain wedge model and Boussinesq solution can provide a theoretical basis for the preliminary design of a single pile under asymmetric scour hole conditions.

To investigate the mechanical behaviors of steel fibre reinforced concrete (SFRC) segments which are firstly used in the test section of the Shanghai Rail Transit Project Line 6, and to propose some useful suggestions for design and construction, a numerical analysis and field test are conducted. The contents of this study involve: (1) the behaviors of the segments against the jacking force, (2) the occurrence and development of cracks, the distribution of stress and strain of segment body, and (3) the distribution of stress and strain in circumferential joints of lining. The results show that safety against the jacking force of shield and the distribution of tensile strain in segment body and joint meet the requirement of design and construction. No cracks have been found in segments under the construction load. This indicates that the steel fibre provides the concrete of the segment with an improved crack resistance. It should be noticed that, although there is no cracks, the maximum tensile strain of rabbets of circumferential joints is much larger than the critical strain of the concrete. It is suggested that the rabbets should be reinforced in design.

A mechanical model of a laterally loaded long pile in layered soils was established to accurately calculate the lateral load-bearing performance of the pile foundation, and attention was paid to the influence of the complete separation of the pile–soil contact surface in a certain part of the pile on its lateral load-bearing performance. Based on the modified Vlasov foundation model, the displacement equation of the laterally loaded long pile embedded in layered soils was derived by the separation variable method. Using the solution method presented in this study, the deformation and internal force of the free-fixed pile were obtained. Then, the effects of the slenderness ratio of the pile and the complete separation of the pile–soil contact surface on the lateral load-bearing performance of the long pile in layered soils were analyzed. The results show that the deformation of the pile body increases with the increase in the slenderness ratio under the lateral load. Meanwhile, the position of the maximum bending moment and the negative shear force moves upward along the pile as the slenderness ratio increases. When the contact surface of the pile–upper stratum is separated, the deformation of the pile top doubles, and the negative shear force increases by three times compared to the case without the effect of separation of the pile–soil contact surface. When the contact surface between the pile and the middle layer soil is separated, the deformation and bending moment of the pile increase by 25%, and the maximum negative shear force decreases.

Preservation and revitalization of historic districts are critical for quality urban development and renewal. Accurately assessing what drives district vitality is essential for sustainable historic area development. Current research often uses cross-sectional data and single models, limiting understanding. This study uses Xigong District, Luoyang, and integrates multi-source data—street view imagery, points of interest, road networks, and nighttime lighting—from 2014 to 2021. MGWR and XGBoost models create a dynamic framework for analyzing how the built environment affects street vitality over time. Results: (1) Spatial effects: Physically, green exposure, functional mix, and road network access are highly spatially sensitive. Morphological indicators—commercial frontage, street continuity, complexity, and building texture—show reduced local variation over time. Perceptually, the influence of abstract color narrows each year, and subjective preference broadens. (2) Nonlinear effects: Green exposure and openness dominate but show negative inhibition and diminishing returns. Morphological, functional, and road network indicators have moderate explanatory power with clear thresholds. Perceptual importance shifts from abstract color to architectural texture, which now rises while color influence steadies. Renewal should go beyond basic greening and surface color. Instead, focus on refined, threshold-based control of form and function, and preserve authentic historic texture. This approach enables scientific, sustainable vitality.