To investigate the sensitivity and significance of different morphological characteristics of plant root systems on vertical pullout resistance, this study considered four main influencing factors: the number of lateral roots, taproot length, the branching angle of the lateral root, and the unit weight of the soil around the root. PC plastic model roots were employed to conduct a vertical pullout orthogonal experiment. A comprehensive ${\mu }_X$ theoretical analysis method based on the whole root system pullout test was applied for a stress analysis on root segments. Based on the results, the factors affected the vertical pullout resistance of plant root systems in the order of number of lateral roots > taproot length > unit weight of soil around the root > branching angle of the lateral root. When the number of lateral roots increased from 2 to 3, the vertical pullout resistance increased by 64%. Also, when the taproot length increased from 50 to 60 cm, the vertical pullout resistance increased by up to 46%. Furthermore, the unit weight of soil around the roots had a positive linear correlation with vertical pullout resistance. Based on the results, the number of lateral roots and the taproot length were the primary factors affecting the magnitude of the root system’s vertical pullout resistance. When selecting plants for slope protection, plant types with a larger number of lateral roots and longer taproots should be considered as the two most significant factors for achieving a better slope protection methodology.

High risk of braking easily causes more safety accidents. In this paper, the driving experiments on G350 Gengda‐Yingxiu section containing continuous downhill tunnel group. Three‐axle trucks under standard load and overload conditions were considered. The research proposes a method for ensuring safe truck driving on continuous downhill sections of mountain roads based on the rise in brake drum temperature. The study collects data on brake drum temperature and braking duration from an experimental vehicle under the coupling action of human‐vehicle‐road‐environment. Through comparative analysis, theoretical derivation, and model construction, conclusions are drawn. The results indicate that the rise in brake drum temperature is influenced by the factors such as overload, alignment, road slope, and sections with bright and dark lines. The initial brake drum temperature, operating speed, and total vehicle mass are identified as the main controlling factors for the change in brake drum temperature. The study also demonstrates that water drenching can significantly reduce the rate of brake drum temperature rise, thereby ensuring driving safety. Furthermore, a model is constructed based on the relationship between brake drum temperature rise and various factors, which allows for the calculation of the corresponding safe slope length and average slope gradient. This model can be used for evaluating or designing overall load requirements. The research on brake drum temperature rise characteristics and braking behaviour under drenching conditions provides effective support for route design, traffic management, and the establishment of safety service facilities.

The existing conventional methods of subgrade disease assessment are not suitable for the existing lines. There are many research studies on the vibration response and attenuation law of the railway subgrade, but few research studies focus on the vibration response and attenuation law caused by the weak subgrade. In this study, vibration response tests were carried out at different positions and depths of the subgrade before and after reinforcement improvement. The results show that vibration response near the ballast is obvious, and it attenuates with the increase of the horizontal distance from the rail; the vibration acceleration response of the subgrade after reinforcement changes greatly; the vibration response curve of the reinforced section is spindle shaped, and the vertical vibration acceleration response attenuates obviously at the depth of 6.5 m, only about 10% to 30% of the surface; the vibration acceleration of the subgrade with reinforcement at the depth of 4.5 m attenuates to 60% of the surface; the vibration acceleration of the subgrade without reinforcement at the depth of 4.5 m attenuates to 50%–60% of the surface.