According to the drawing load characteristics of horizontal rectangular anchor plate in red clay foundation, the vertical drawing model test of horizontal rectangular anchor plate in saturated red clay foundation is carried out by using a self-made visual drawing model test system combined with digital photographic measurement technology. The results show that the sliding surface of soil around the anchor shows different shapes with the change of buried depth ratio, but the initial Angle does not change with the change of buried depth ratio. The load displacement curve generally has obvious peak characteristics, but with the increase of the buried depth ratio, the characteristics gradually weaken. When the buried depth ratio is the same, the smaller the length-width ratio is, the more obvious the three-dimensional bearing characteristics of the anchor plate and the peak characteristics of the curve are. The bearing capacity coefficient increases with the increase of buried depth ratio, but the law is different under different aspect ratio. The bearing capacity coefficient decreases with the increase of length-width ratio, and the change law is consistent under different buried depth ratio. Conclusion: For test red clay, the anchor plate can be classified as shallow buried type at least within the range of buried depth ratio 4, and deep buried type if the buried depth ratio is greater than 8. Under the same conditions, under the influence of cohesion and dilatancy, the tensile strength coefficient of anchor plate in red clay foundation is between loose sand foundation and dense sand foundation.

In order to further study the connectivity and hydraulic connection between the injection and production wells in geothermal reservoir, a dual media model of fracture-porosity was constructed by using COMSOL Multiphysic.The effects of the aperture of the fissure group in fractured rock mass, the diffusion coefficient of the rock matrix, and the permeability on the tracer breakthrough curve (BTC) at different dip angles with the mainstream direction were analyzed.The results indicate that the convection of water in the fissure is the main factor influencing the concentration migration. With the increase of the fissure aperture, the migration rate and peak concentration of the tracer are enhanced, and the degree of the influence on the tracer migration by the fissure aperture decreases with the increase of the dip angle of the fissure group. The diffusion coefficient and permeability of the rock matrix have a significant impact on the temporal and spatial distribution of the tracer concentration. With the increase of the matrix diffusion coefficient, the delay effect of the tracer migration is elevated. With the increase of the matrix permeability, the anisotropy of the reservoir pressure and concentration distribution is reduced, and the concentration distribution at the outlet boundary becomes more uniform.

To investigate the deformation characteristics of tunnels under impact and blast loads, A combination of model testing and numerical simulation was proposed to analyze the damage behavior and patterns under various dynamic loading conditions. The Hailuogou Tunnel was studied, and a combination of model testing and numerical simulation was utilized. Initially, an impact test was performed on the scaled-down physical tunnel model. Subsequently, numerical analysis of the tunnel model was conducted and verified. Then, a comparison was made between the tunnel deformation results of the scaled model and the prototype model under impact load. Finally, the effect of blasting load on the deformation of the prototype tunnel was analyzed. The results indicated that the proposed method accurately reflected the actual impact load’s effect on tunnel deformation. Additionally, the numerical analysis results of the scaled tunnel model closely matched the test results. Moreover, the deformation of the top of the prototype tunnel under the impact load was approximately 10 times greater than that of the scaled tunnel model, and it aligned well with the deformation caused by a blasting load equivalent to 500 kg of TNT. The impact load effectively simulated damage to the tunnel vault. Increasing the depth of cover and reducing the impact load represented effective measures to mitigate significant tunnel damage. The challenges of on-site testing during surface blasting are surmounted by this study’s findings. Additionally, a cost-effective, safe, and dependable testing approach is furnished for analyzing the destructive behaviors and modes of tunnels under various dynamic loads. Furthermore, technical support is offered for the safe and economical design of tunnels with optimized blasting loads.

Previous studies on visual effects primarily focus on evaluating the overall urban environment, lacking specific research on historical districts within cities. In order to evaluate the visual effects of plantscapes in historic districts, street view images and machine learning methods were used. The ResNeSt model was selected to assess the coordination and health of plantscapes. The results show that the ResNeSt model performs best in classification and regression tasks. Its scores are consistent with expert evaluations and moderately to highly correlated with public evaluations. Additionally, the visual effects of plantscapes are significantly influenced by economic factors, with the visual effect scores of streets outside the historic districts generally higher than those inside. It is concluded that machine learning models are highly effective in evaluating the visual effects of plantscapes in historic districts. This provides a scientific basis for their protection and optimization, with important implications for urban planning and tourism.

During the parallel operation of excavation and concrete lining construction in the diversion tunnel, the quality of construction was significantly affected due to the severe damage to the floor concrete caused by heavy truck crush. In response to the challenging problem of floor concrete protection caused by heavy truck crush during the “excavation-lining” parallel operation in the diversion tunnel, a numerical calculation model for floor protection was established using ABAQUS. Adopting the floor protection measure of overlaying “tunnel excavation debris-concrete” composite protection layer, a numerical simulation study on the protection of tunnel floor concrete was conducted. The influence patterns of the material characteristics of the protection layer and the bias distance of the heavy truck on the stress and deformation of the floor concrete were analyzed, and the effectiveness of protection under different working conditions was evaluated. The study results indicated that the floor protection measures could effectively improve the protection of the floor concrete. As the concrete grade of the protection layer increased, the stress and deformation of the floor concrete decreased, with the reduction rate reaching up to 17.5% and 12.4% respectively. Furthermore, as the bias distance of the heavy truck increased, the maximum deformation of the floor concrete increased, and the range of deformation expanded significantly. Moreover, stress growth was extremely pronounced at the edges, with a maximum growth rate of up to 222.6%. The research results can provide theoretical and technical guidance for the protection of the floor concrete against crush damage in the diversion tunnel.

In the winter water transfer process of the Northwest cold region long-distance water transfer project, channels and hydraulic structures such as gate piers are frequently subjected to damage from flowing ice impacts. To safeguard the stability and security of winter water transfer operations, it is imperative to investigate the mechanical response characteristics of gate piers under the influence of flowing ice impact. ANSYS/LS-DYNA finite element software was employed to establish a refined finite element model of the gate pier under ice-water coupling conditions using the arbitrary Lagrangian-Eulerian (ALE) fluid-solid interaction method. The accuracy and validity of the numerical model are were verified by comparing the impact forces of flowing ice against relevant standards. The mechanical response characteristics of flowing ice on the gate pier by varying models such as the ice-water coupling model, additional mass model, fluid-free model, and flowing ice characteristics (velocity and compression strength)was explored. The findings indicated that the impact damage from flowing ice on the gate pier primarily occurs at the collision contact area between flowing ice and the gate pier. The presence of the water medium significantly mitigates the damage caused by flowing ice, emphasizing its viscous effects. Comparing different collision condition models, the additional mass model exhibits the highest impact force and X-direction displacement peak values, followed by the fluid-free model, with the fluid-solid coupling model showing the least impact, thereby suggesting the suitability of the additional mass model for simulation calculations and structural design. Furthermore, the result revealed that both the peak and mean impact forces increase with higher flow ice velocities and compression strengths, underscoring the importance of considering these factors in impact force assessments. Practical measures such as installing ice stopping ropes are recommended to mitigate flow ice impact forces and ensure structural safety in real-world applications.

Variations in freezing and thawing of the roadbed are known to significantly influence the dynamic behavior of high-speed railway ballast tracks. This phenomenon potentially compromises the safety and efficiency of train operations. A comprehensive vehicle-ballastless track-roadbed spatial dynamic model was employed to examine the effects of different wavelengths, amplitudes, and velocities on track dynamics due to roadbed frost heave. It was found that, with a constant heave amplitude, an increase in wavelength initially boosted and then reduced the car’s vibration acceleration. Concurrently, the vertical wheel-rail force diminished as the wavelength extended, leading to a decrease in both the wheel load reduction rate and the risk of derailment. Conversely, when the wavelength was kept steady and the heave amplitude was increased, the car’s peak vibration acceleration escalated. At a 40 mm amplitude, the vertical wheel-rail force peaked at 198.642 kN before dropping to zero within 1.384 seconds, resulting in a brief airborne phase for the car. An increase in heave amplitude heightened both the wheel load reduction rate and the derailment coefficient, reaching critical safety thresholds at a 35 mm amplitude. Higher driving speeds intensified the dynamic indicators of the rail system.These insights provide crucial guidance for analyzing dynamic challenges in high-speed railway tracks and addressing structural issues effectively.

The current safety evaluation standards lack guidance on the alignment design specific to lower-grade highways, such as four-lane and non-standard highways. To address this issue, a method for assessing the driving safety of mountainous highways with low index and complex alignment was proposed. The method involved building a human-vehicle-road system simulation using the CarSIM/TruckSIM simulation software platform, selecting representative car models, and using realing vehicle driving data as simulation parameters to carry out virtual vehicle driving tests. Four categories of indicators, including speed, lateral stability, driver handling, and speed regulation, were used to examine and analyze the compliance of the tested highway’s geometric design, speed coordination, driving operation load, identification of accident-prone sections, and safety of continuous uphill sections. The feasibility of the “human-vehicle-road” simulation method was verified by running virtual simulation driving tests similar to the real-vehicle test, and one four-lane highway and one non-standard highway were selected as examples. The results demonstrate that this method can effectively identify alignment design combinations that are below the limit and inconsistent, as well as road sections with high driver handling loads and poor balance. It can also identify dangerous road sections, corresponding vehicle accident patterns, critical safety speeds, and positions and widths where heavy-duty trucks deviate from the travel lane when passing through hairpin curves. Based on the driving/accident conditions of dangerous road sections, targeted geometric parameter improvement measures can be proposed to enhance the trafficability and stability of vehicles on ordinary mountainous highways with low index and complex alignment, ultimately improving the quality of alignment design and driving safety for low-index highways in mountainous areas.

To solve the issue of insufficient durability for steel bridge deck pavement, two types of double-layer stone mastic asphalt (SMA) pavement structures were used as research objects. Firstly, the most unfavorable loading position of the typical bridge deck was determined through the finite element analysis method; and the mechanical response of the above two structures at this loading position was calculated, thus the optimal structural combination for steel bridge deck pavement and its design index requirements were proposed. Secondly, two types of high viscosity and elasticity modified asphalt (A and B) were prepared; and then, taking the road performance of asphalt binders and their mixtures as the evaluation criteria, effects of asphalt binder’s types on the road performance of steel bridge deck pavement asphalt mixtures were compared, thus the asphalt binder with the best properties was selected. Finally, the bonding performance between the pavement layer and the steel plate was evaluated by using the indoor pull-out and oblique shear tests. Meanwhile, the bonding performance of the pavement layer under the most unfavorable temperature conditions was tested with the actual engineering. Test results show that the middle position is the most unfavorable load position on the steel bridge deck. Therefore, the tensile stress, vertical displacement, and bottom shear stress of the pavement layer at this location can be selected as the main design indicators for steel bridge deck pavement. In addition, the two designed pavement structures exhibit the consistent mechanical response patterns, among which the vertical displacement and layer bottom shear stress of structure 2 (SMA-13+SMA-10+asphalt mortar) are relatively smaller. As for the asphalt binders, comparing with SBS (styrene butadiene styrene triblock copolymer) modified asphalt, the prepared high viscosity and elasticity modified asphalt (A and B) have the better road properties, among which the road property of A modified asphalt is the best. The pull-out test results show that, under the temperature conditions of 25 ℃ and 60 ℃, the bonding strength between the pavement layer and the steel plate can all meet the design requirements. The actual engineering test result show that temperature inside the pavement structure layer exhibits the periodic variation pattern, with the highest temperature not exceeding 60 ℃. Therefore, the design index based on the interlayer bonding strength at this temperature is scientific and reasonable, and meanwhile, the interlayer bonding strength of various structural layers in the actual engineering meets the design requirements under this unfavorable temperatures.

To achieve safe and efficient replacement of stay cables that exceeded their designed service life or suffer serious damage, a stay-cable replacement system (SRS) was proposed which used the existing cable-stayed anchor plate (ECAP) as a reaction force system. The scaled model of the typical main girder segment and the full-scale model of the SRS were designed and produced. The axial compression and eccentric compression static tests were carried out under the conditions of dry contact and adhesive contact between the steel anchor barrel (SAB) of SRS and the ECAP. The results show that, under dry contact conditions, the failure mode of the SAB is the buckling of the contact point between the eccentric compression side of the SAB end and the ECAP. Under adhesive contact conditions, the failure mode of the SAB is the buckling at the interface between the eccentric compression side of the SAB and the epoxy resin glue. After pouring of the epoxy resin glue, the displacement and maximum compressive stress of the SAB are smaller, and the compressive safety and stability of the SAB are better. The proposed SRS can be applied in stay-cable replacement.