Qianghui Song

The absence of national standards and theoretical guidance for fog zone lighting on expressways poses critical challenges to driver safety. This study investigates how pavement color and fog guidance light spacing jointly influence driver visual cognition and behavior in fog environments, addressing an important gap in understanding human-vehicle-road-environment interactions. A driving simulator experiment was conducted under varying pavement colors (yellow, red) and light spacings (20 m, 30 m, 40 m). Drivers' physiological responses (skin conductance, pupil diameter) and behavioral indicators (speed, acceleration) were collected to assess visual cognitive load and driving stability. Results reveal that the combination of yellow pavement and 30 m light spacing yields optimal driver performance: shortest speed stabilization time, fewest abnormal acceleration fluctuations, and most concentrated physiological responses, indicating reduced cognitive load and enhanced driving stability. Red pavement enhances visual contrast and induces physiological arousal, serving a strong warning function, while yellow pavement facilitates smoother deceleration and speed regulation. Light spacing modulates driver visual compensation by altering the continuity of roadside illumination. A neurothermodynamic evaluation further shows that the optimal configuration achieves the lowest entropy production rate and minimal neural disorder, reflecting more efficient visual information processing. These findings elucidate the coupling mechanism between pavement color and light spacing on driver perception and behavior, providing theoretical insights for designing fog zone infrastructure that supports safer driver-environment interaction.

To study the generation and dissipation process of agglomerate fog in mountainous expressways and deeply understand the hazard mechanisms of agglomerate fog sections in mountainous expressways, based on the analysis of the geographical location characteristics of mountainous expressways and the spatial and temporal distribution characteristics of agglomerate fog, the airspace constitutive model of agglomerate fog in mountainous expressways was constructed based on Newton constitutive theory. Firstly, the properties of the Newtonian fluid and cluster fog were compared and analyzed, and the influence mechanism of environmental factors such as the altitude difference, topography, water system, valley effect, and vegetation on the generation and dissipation of agglomerate fog in mountainous expressways was analyzed. Based on Newton’s constitutive theory, the constitutive model of temperature, humidity, wind speed, and agglomerate fog points in the foggy airspace of the mountainous expressway was established. Then, the time and spatial distribution of fog in Chongqing and Guizhou from 2021 to 2023 were analyzed. Finally, the model was verified by using the meteorological data and fog warning data of Liupanshui City, Guizhou Province in 2023. The results show that the foggy airspace of mountainous expressways can be defined as “the space occupied by the agglomerate fog that occurs above the mountain expressway”; The temporal and spatial distribution of foggy airspace on expressways in mountainous areas is closely related to the topography, water system, vegetation distribution, and local microclimate formed by thermal radiation. The horizontal and vertical movements of the atmosphere have little influence on the foggy airspace on expressways in mountainous areas. The specific manifestation of time distribution is that the occurrence of agglomerate fog is concentrated from November to April of the following year, and the daily occurrence time is mainly concentrated between 4:00–8:00 and 18:00–22:00. The calculation results of the foggy airspace constitutive model of the expressway in the mountainous area show that when there is low surface radiation or no surface radiation, the fogging value range is [90, 100], and the fogging value range is [50, 70] when there is high surface radiation (>200), and there is generally no fog in other intervals. The research results can provide a theoretical basis for traffic safety management and control of mountainous expressway fog sections.

To obtain the optimal driving visual guidance methods in sudden low-visibility fog environments, it is crucial to analyze the changes in visual characteristics and information demand under low-visibility foggy conditions. The paper constructs a driving visual information demand model for foggy environments based on visual information input and output, using Shannon’s theory and feedback control theory. Two types of foggy road sections with the same visibility, one with guidance lights and one without, were selected for real-vehicle experiments based on the driver’s blood pressure, heart rate, and driving gaze domain tests. The study found the following: (1) In sudden foggy environments, the amount of driving information obtained by drivers decreases instantly with a sudden drop in visibility, failing to meet the information demand for driving cognition, thereby disrupting the dynamic balance state of driving based on speed, visibility, and other road environment factors. The experiment also found that in low-visibility environments, the radius of the human eye’s visual gaze domain becomes smaller, with the gaze range mainly concentrated directly in front of the vehicle, and the lower the visibility, the smaller the gaze domain range; (2) Foggy conditions affect changes in drivers’ blood pressure and heart rate. Installing guidance lights with sufficient illumination at foggy sections to compensate for drivers’ visual information can effectively supplement the visual information required for safe driving; (3) The experiment indicates that the guidance effect of the lights is most pronounced when visibility is within the range of [50 m, 150 m]; however, when visibility is above 500 m, the presence of guidance lights can, to some extent, affect driving safety and increase the risk of accidents.

Through the application of SHPB (split Hopkinson pressure bar) test, the failure mode and dynamic stress-strain curves of marble samples were obtained. The dynamic constitutive model of marble was established with the fracture mechanical parameters (brittleness index), and the calculated curves were compared with the experimental curves. The evolution characteristic of damage variable was analyzed. The results show that there are three main stages of marble deformation under dynamic impact load, which are linear elastic deformation stage, crack growth stage, and macroscopic failure stage. The sample shows obvious brittleness in the macroscopic failure stage. It is found that with the increase of strain rate, the degree of damage is getting worse. The stress-strain curves obtained based on the constitutive model are in good agreement with the experimental curves. The damage variable can theoretically explain the evolution law of macroscopic failure of the sample. To some extent, there is a mechanism inside the rock to regulate the damage development of the rock, and the final failure degree of rock sample depends on and .

The fracture behaviors of rocks under dynamic loading are significantly affected by flaws. Understanding regarding this fundamental mechanism of flaw-induced dynamic fracturing could aid in reducing dynamic geohazards in deep rock engineering. In this study, a series of dynamic loading experiments are conducted on conjugate flawed white sandstone specimens to study the effect of the geometric configuration of flaws on dynamic fracturing. The results show that the geometry configuration of flaws and the loading conditions both strongly affect cracking and failure behaviors. Two types of shear cracks and three types of tensile cracks are observed, four coalescence patterns are identified, and the global failure modes of rock are usually coupled with two or more coalescence patterns. The inhibiting and enhancing mechanism of flaws in regards to potential shear fracture are obtained. These two failure mechanisms depend on the angular relationship between the flaws and the potential shear strain field. The “guiding effect” of the flaws results in the deviation and deformation of shear cracks. Moreover, it is found that the loading condition dominates the fracture tendency of rock macroscopically, while the geometric setting of flaws significantly affects the fracture behavior and failure mode locally.

Investigations on rock dynamics have been comprehensively focused on when the dynamic impact is perpendicular to the trend of the flaws, while understanding the dynamic mechanical properties and failure characteristics of rock with pre-flaws parallel to the loading direction remains unrevealed. In this study, impact tests are performed to experimentally study the dynamic mechanical properties, failure characteristics, and energy evolution of pre-flawed sandstone using the split Hopkinson pressure bar (SHPB) apparatus, in which the pre-flaws are parallel to the loading direction. The results show that for specimens, the dynamic loading rate and the number of flaws greatly influence the dynamic strength, peak strain, energy absorption rate, and failure behaviors. The dynamic strength increases exponentially with an increase in loading rate and decreases with an increase in flaw numbers. The fractal dimension of triple-flawed specimens is the largest at the same loading rate range. The failure modes of different pre-flawed specimens show a transition from tensile failure to tensile-shear failure with the increase of dynamic loading rate.

Rock engineering is highly susceptible to cyclic loads resulting from shale gas exploitation; it is very important to study the failure mechanism of underground rock mass under cyclic load. To investigate the energy dissipation and damage evolution characteristics of shale under triaxial cyclic loading and unloading conditions, a series of triaxial incrementally cyclic loading and unloading tests under different confining pressures (10 MPa, 15 MPa, 20 MPa, and 30 MPa) were carried out. The variation of plastic strain of shale under four confining pressures was analyzed, and the evolution characteristics of dissipated energy and energy dissipation ratio were discussed. The results show that: the peak strength and peak strain of shale increase with the increase in confining pressures. Meanwhile, the plastic strain of rock under cyclic loading increases rapidly first, then develops steadily, and finally increases sharply with the increase in axial strain. The energy dissipation ratio-strain curve presents a spoon-shaped evolution feature, and can be divided into three stages: a linear decline stage, a steady development stage, and a rapid increase stage, respectively. However, the trend of elastic modulus of shale was opposite to that of the energy dissipation ratio. Accordingly, the energy dissipation ratio can be regarded as the damage factor to describe the degradation of shale. Based on the evolution of dissipated energy, a theoretical equation of shale stress-strain evolution was established. By substituting the test data into the formula, it is found that the calculated results are basically consistent with the test data, and the peak strains and peak stress calculated by the equation are in good agreement with the test data. The findings could provide important theoretical support for the energy dissipation and damage evolution analysis in the failure process of shale under cyclic stress conditions.

Informatization is the core of modern military development. It is necessary to pay attention to and strengthen the informatization construction of military key laboratory to win the information war. Based on the analysis of the traditional management mode of laboratory and its disadvantages, combined with the practice and exploration of information construction and management of military key laboratory of military underground construction engineering in recent years, this paper comprehensively analyzes and deeply discusses the achievements and experience of laboratory in information construction and management, as well as the existing problems and lessons. Practice shows that the laboratory has made significant progress and benefits in the information construction and management, but there are still some contradictions and problems to be solved.

Lijiadagou landslide and debris flow hazards chain in Yong’an Town of Fengjie county is one of the representative geohazards. By using satellite remote sensing technology, field investigation and observation, survey and analysis, mechanical analysis and other technical means, this paper makes qualitative or semi quantitative analysis on the hazard environment, instability probability, vulnerability analysis of elements at risk, risk loss, etc. The risk factors of Lijiadagou landslide and debris flow were identified. The conclusion shows that the unique landform and climate of Lijiadagou lay a foundation for the occurrence of multiple debris flows in the history. Under the alternate control of multiple factors such as the nature of the rock and soil mass, the stratum structure that controls the sliding, the complex geomorphic environment, continuous heavy rainfall and the rise and fall of the water level, there are high risks of landslides and debris flows, threatening about 6,000 residents in the middle and front range of Lijiadagou. The risk economic loss of hazards is about 80 million yuan, and will cause serious social impact. It is urgent to strengthen monitoring and early warning, and at the same time take targeted measures against the landslide source area to cut off the hazards chain from the source, so as to achieve a multiplier effect with half the effort.