In order to study the influence of the space linkage system on the stability of the straddle-type monorail vehicle with single-axle bogies, the sensitivity analysis of the space linkage system is identified based on the Pearson coefficient method to determine the importance of each component of the single-axle bogies. The dynamics model of straddle-type monorail vehicle with single-axle bogies is established by the multi-rigid body dynamics. The Pearson analysis method is used to identify the key parameters of the space linkage system. Based on that, dynamic response optimization model of space bar system is developed to carry out a multi-objective suspension design optimization process. The results show that the maximum sensitivity parameter for the RMS value of yaw acceleration and pitch angle acceleration is the length of the longitudinal tow bar; there is a correlation of approximately 0.088 between the stiffness K and the damping coefficient C of the hydraulic shock absorber. After optimization the root mean square of lateral acceleration of the optimized single-axle bogie vehicle is reduced by 6.0%.

The erosion of the seabed around offshore structures has emerged as a critical factor impeding the operational safety of offshore engineering facilities. Prompt and precise identification and monitoring of the water–soil interface hold significant importance in mitigating the seabed erosion challenges facing offshore structures. To tackle this issue, a monitoring framework for the water–soil interface is proposed, grounded in heat transport theory. This framework exploits the thermodynamic variances between seawater and the seabed soil to examine the temperature changes in linear heat sources in water and soil under a constant power. In this study, a typical metallic material—iron (Fe)—and non-metallic material—polyvinyl chloride (PVC)—are considered the linear heat sources, and their temperature variations are analyzed within this framework. The findings reveal that the temperature of the linear heat sources rapidly stabilizes, with the ultimate temperature exhibiting a logarithmic correlation with the convective heat transfer coefficient. To further test the practicability of the framework, an indoor test is conducted. The errors between the theoretical calculation results and the experimental results are less than 14% in water and 19% in soil. The results of the framework and the indoor test have a high degree of coincidence. This framework has proved that it can be used in practical engineering.

The erosion and sedimentation of bank slopes are important factors affecting the safety of wharf operations. The essence of bank slope monitoring is to identify the water–soil interface. This paper proposes a model for soil-and-water interface identification and monitoring equipment buried on the bank slope of the wharf, based on the difference in thermodynamic heat transfer between water and soil media, and presents the results of multi-condition numerical simulation. The comparison between numerical simulation results and indoor experimental results shows that the overall patterns are consistent, with an error of less than 11.4%, which is lower than the deviation between theoretical calculation results and indoor experiments. Based on the accuracy of the numerical calculation results, the temperature rise and propagation characteristics of linear heat sources made of iron and PVC in eight types of cohesive soils and six types of non-cohesive soils were studied. The results indicate that there are significant differences in the temperature distribution of linear heat sources made of iron and PVC in both water and soil media. The monitoring equipment model based on the difference in heat transfer between water and soil can be applied in practical engineering. This provides a foundation for the design and application of subsequent monitoring equipment.

The scouring and sedimentation of wharf bank slopes significantly impact port safety and efficiency. To overcome the limitations of existing monitoring technologies in real-time capability, adaptability, and precision, this study introduces an innovative device based on distributed fiber optic sensing technology. By analyzing changes in the temperature gradient at the water–soil interface, the device enables dynamic monitoring of the results of scouring and sedimentation processes. It employs a modular design, integrating a linear heat source with fiber optic temperature sensing to capture high-resolution changes. Laboratory experiments evaluated variables such as heating duration, pipe material, pipe diameter, and fiber winding pitch. Results show optimal performance with a 20-min heating duration, with PVC sensors offering higher sensitivity and steel sensors providing greater stability. This study presents a high-precision, real-time solution for monitoring wharf bank slopes, offering insights for equipment optimization and engineering applications.