Lithologic Structure of the Anninghe Fault Zone: Constraints From High-Pressure Wave Velocity Experiments

The P-wave velocities of typical rocks in the Anninghe fault zone under pressures of 50–600 MPa were systematically measured. The P-wave velocities of the felsic, intermediate, and mafic rock types under atmospheric pressure were 5.86, 6.06, and 6.50 km/s, respectively, with pressure coefficients of 2.19 × 10–, 3.80 × 10–4, and 4.03 × 10–4 km/s/MPa, respectively. The results were combined with deep-imaging seismic data to establish crustal rock composition models at different depths in the study area. The composition of the Anninghe crust is very different in the horizontal and vertical directions. The most notable feature in the vertical direction is that the lithologic compositional change is gradual rather than abrupt with increasing depth. In the middle and upper crust, shallower than 25 km, the lithologic difference between the southern and northern sections of the Anninghe fault zone is primarily that the rocks in the southern section (Xichang) are more felsic than those in the northern section (Shimian).</jats:p

Analysis of the Severity of Heavy Truck Traffic Accidents Under Different Road Conditions

The rising frequency of heavy truck accidents in China poses a significant public safety risk, endangering lives and property. However, current research based on data from heavy truck accidents in China remains limited, making it challenging to support the formulation of traffic management measures. To mitigate the severity of these accidents, this study analyzed five years of heavy truck accident data from a specific region in China and developed logistic regression models for different road conditions. The aim was to identify the key factors influencing accident severity and understand the underlying mechanisms. The findings revealed that, under urban road conditions, the severity of heavy truck accidents is significantly impacted by factors such as lighting conditions, road safety attributes, driver age, and vehicle driving status. On highways, accident severity is largely influenced by visibility, roadside protection measures, intersection and section types, vehicle driving status, inter-vehicle accident types, and road safety features. On expressways, critical factors include inter-vehicle accident types, driver violations, visibility, and road alignment. In conclusion, the factors contributing to the severity of heavy truck accidents vary according to road conditions, which necessitates tailored traffic management strategies. The study&rsquo;s findings offer theoretical support for more targeted approaches to preventing and controlling heavy truck traffic accident severity under different road conditions in China