【摘要】 针对小环岛立交线形指标低、曲率曲折多、曲线参数多、整体连续性和安全性能差的特点,提出采用双纽曲线应用于小环道,并分析了其路用性能和综合效益。结果表明:双纽曲线由于曲率变化率均匀,除了进道和出道,不存在曲率突变情况,线形连续,整体性能好,而且离心加速度变化率小,行车舒适;当实际行车速度不超过设计速度的25%时安全性高;采用双纽曲线能够减少占地面积,当缓和曲线越长时越经济。在整体式小环道中,双纽曲线可以作为一种补充方法予以借鉴推广。更多还原

【Abstract】 Based on the characteristics of the small roundabout interchange of low linear indicator,many twists and turns and curves parameters,poor overall continuity performance and security,the paper proposed to use Lemniscates curve in the small ring road and analyzed its road performance and comprehensive benefits. The results showed that: because of the uniform rate of change of curvature,there is no curvature mutation,and the linear is continuous,so the overall performance is good in addition to the exit and the entrance. More importantly,the linear has small centrifugal acceleration change rate and the high-performance security. If the actual vehicle speed is below 25% of the design speed,the traffic safety is very satisfactory. Meanwhile,the curve can reduce the floor space requirements,and the longer the transition curve,the more economical efficiency. Therefore,the lemniscates curve can be used as a complementary method to reference and promote in integral small ring road.更多还原