Investigation on lateral instability of vehicles crossing urban viaducts excited by strong earthquake motions

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K18899
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Civil engineering and related fields
• Research Institution: Yokohama National University
• Principal Investigator: FUJINO Yozo 横浜国立大学, 先端科学高等研究院, 特任教員(教授) (20111560)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Keywords: 地震 / 走行自動車 / 転倒解析 / 交通

Outline of Final Research Achievements

The vehicle model including out-of-plane and in-plane motion along with effect of curved line with specific radius, camber angle and longitudinal grade is developed. The vehicle stability is evaluated by the rollover and sideslip stability. Numerical simulations were conducted using a highway junction consisting of four curved sections and two straight sections. Effects of curved bridge radii, level of earthquake, vehicle velocity and driver reaction on the vehicle stability were evaluated. It was found that vehicle moving on a curved bridge during large earthquakes has a larger possibility for rollover and sideslip stability than vehicle moving on a straight section for the same driving velocity and level of earthquake. Reduction of normal forces on vehicle’s wheels associated with curved bridge effect and steering angle, effect of road camber at the curved section all contributed to the higher risk of instability in addition to earthquake-induced acceleration of bridge deck

Free Research Field

構造工学

Academic Significance and Societal Importance of the Research Achievements

トラックの高架橋上での地震時転倒は1995年兵庫県南部地震において発生しているが，この問題を扱った研究は世界で皆無であった．都市内高架橋におけるトラックの転倒は地震後の交通機能低下につながる大問題であり，今回の研究でL2レベル地震では曲線部はもとより直線部でも転倒滑動の高い可能性が極めて高いこと，強度がL2の半分程度の地震でも曲線部では転倒の可能性が高いことが判明したことは極めて意義が高いと言える．