Research On Multi-scheme Evaluation Method Of Underground Road Considering Longitudinal Slope Index

With the continuous growth of China ’s economy,increasing vehicle ownership,the existing road infrastructure capacity tends to be saturated,the road has been difficult to meet people ’s travel needs.In recent years,underground roads have been widely used in China.For new roads,whether the selection of longitudinal slope scheme is reasonable will affect the design quality,operation and engineering cost of roads.Therefore,it is necessary to study the evaluation methods of different longitudinal slope index schemes of underground roads from multiple perspectives.Firstly,this paper discusses the project background and engineering overview that this paper relies on,and then consults relevant research results at domestic and abroad.On the basis of fully understanding the influencing factors of longitudinal slope at domestic and abroad,this paper research the evaluation method of underground roads from four aspects : truck dynamics,exhaust emissions,parking sight distance and traffic capacity.Considering the speed attenuation of vehicle in the process of climbing,based on Truck Sim simulation software,the speed reduction of vehicle in the longitudinal section is studied.Considering the poor ventilation in the closed environment of underground road,the exhaust emission was studied based on Moves.Based on UC-Win Road simulation software,the real scene model is established,which can be used to study the vertical section sight distance.Based on VISSIM traffic flow simulation,the road traffic situation is studied.Based on the engineering practice,this paper studies the evaluation methods of different longitudinal slope index schemes of underground roads,demonstrates the rationality of different design schemes of underground roads,finds the hidden defects in the design process and the factors that cause accidents and pollution hazards,and reduces the potential risk of traffic safety.At the same time,it can provide theoretical reference for the evaluation of multiple schemes of underground roads in the future.