Research On The Spatiotemporal Distribution Characteristics And Application Of Wind Speed Along High-speed Railways Based On W

The safe operation of high-speed rail is closely related to the meteorological environment around the train,and high wind is one of the main meteorological disasters affecting the safety of high-speed rail.At present,Chinese high-speed rail wind warning system has not yet achieved real-time prediction of wind speed alarm,while the deployment of wind speed monitoring points along the line is not scientific enough.For this reason,there is a need to carry out targeted analysis of the spatial and temporal distribution characteristics of wind speed along high-speed rail lines.On the one hand,it will help the railway department to deepen the understanding of the wind field environment along the high-speed rail line,and provide important references for the layout of windshield walls and the optimization of the layout of wind measurement stations along the line.On the other hand,the study can also provide an intrinsic antecedent basis for accurate positioning of the speed limit zone and the realization of advance prediction and warning of high winds along the high-speed rail line.In view of this,with the support of the key projects of the National Railway Group and the major projects of the National Railway Shanghai Bureau Group,this paper selects the typical areas(area A and B)of the Jiangsu section of the Beijing-Shanghai high-speed railway with complex terrain and prone to strong winds as the research object.By carrying out the research on the roughness model of the optimized hydrodynamic WT model,the digital simulation of the spatial and temporal distribution characteristics of wind speed in the study area is realized,and a crosswind index is proposed to characterize the coupling relationship between wind speed and direction along the high-speed rail line.Based on the crosswind index,a new site layout optimization method.The details are as follows.(1)The wind profile method and wind speed standard deviation method are used to calculate the seasonal roughness of town and farmland subsurface along the railroad lines in areas A and B,which is compared with the default value of WT model and existing research results,and specifically analyze the characteristics of the roughness of the lower bedding surface with wind direction and seasonal changes.The results show that the WT roughness model ignores the spatial and temporal variation characteristics of the roughness of different cover types and cannot meet the requirements of small-scale wind field simulation in complex environments.In order to improve the WT simulation accuracy,the WT roughness model was optimized respectively using the calculated four-season roughness values of town and farmland sub-bedding surfaces in the two regions,and the four-season wind speed data of the measured stations along the railroad lines in the two regions were simulated by the WT before and after the optimization respectively.The simulation data before and after optimization were compared and analyzed with the measured data to obtain three evaluation indexes of RMSE,MAE and R,which verified that the roughness model optimization could significantly improve the simulation accuracy of WT.(2)By analyzing the wind speed of the Jiangsu section of the Beijing-Shanghai high-speed railway for the past 40 years,we selected the A and B areas along the railroad line with complex topography and prone to high winds to carry out a study on the spatial and temporal distribution characteristics of wind speed.The optimized WT model was used to model the wind field and simulate the site fixation calculation in the two areas,so as to obtain the simulated site wind data and meteorological maps in these areas.The characteristics of wind conditions,spatial and temporal distribution of strong crosswinds and spatial distribution of wind shear index in the two areas were analyzed by means of mathematical statistics.According to the results of the study,specific protective measures such as the setting of wind break walls were proposed along the railroads in the two areas,and opinions such as the reasonable deployment of stations were given.(3)For high wind alarms along high-speed rail lines that do not take into account wind direction,this paper proposes a crosswind index(CWI)that characterizes the wind speed and wind direction coupling relationship,and through the analysis of CWI changes in specific high wind alarm events shows that overreporting can be reduced by judging the value of CWI.Moreover,the spatial and temporal distribution characteristics of strong crosswind index highlight the susceptibility of trains at some time nodes and spatial geographic locations,which provides a reference for the safety and operational efficiency of high-speed rail.In addition,this paper further proposes an optimization scheme of station layout along the railroad line based on the crosswind index.The program combines the spatial and temporal distribution characteristics,using the dichotomous K-mean method and Critic method to optimize the deployment of sites,and through the optimized deployment points and the actual deployment points along the railroad line comparison analysis,verify the program can effectively monitor the wind speed and direction characteristics of the Jiangsu section of the Beijing-Shanghai highspeed railway,but also reduce the site redundancy,to provide reference for the layout of wind measurement sites along the high-speed railway.