中文摘要：

宁沪杭高铁的开通缩短了长三角城市之间的交通时间。通过缩减交通时间拉近城市间空间距离，高速铁路的贯通对长三角城市群交通网络空间结构产生深远影响。城市间联系会因交通时间缩短而增强，以交通距离代替空间距离来研究城市群之间分形特征更具有科学性。从城市间高速时间距离和高铁时间距离对比角度，计算高铁开通前后长三角城市群交通空间聚集维数和空间关联维数，分析长三角城市群交通网络空间结构分形特征变化。结果表明：高铁下的长三角城市群交通网络空间向心性集聚分布更显著，空间关联性更强。不同级别交通网络相互叠加改变城市群交通网络分形特征。高铁开通优化了长三角城市群城市交通网络空间结构。

英文摘要：

The traffic time between Yangtze River Delta cities is shortened by the opening of the Shanghai- Nanjing, Shanghai-Hangzhou high-speed railway. Through the way of reducing traffic time, the space distance of cities become closer. The urban transportation spatial structure fractal characteristics of Yangtze River Delta City Group will be made great change due to the opening of high-speed rail. The contact among cities will be enhanced with the shortening of traffic time. Using transport distance instead of space distance to study the fractal characteristics of urban agglomerations is more scientific. From the angle of contrasting high speed time distance and high-speed railway time distance of Yangtze River Delta City Group, the traffic space aggregation dimension and spatial correlation dimension around the opening of high speed railway is calculated, in order to analyze its traffic space structure fractal feature. The results indicate that under the function of high speed railway, the transportation network spatial centripetal distribution of Yangtze River Delta City Group is more significant and the spatial correlation is closer. Different levels of traffic network stacking with each other changes the transportation network fractal characteristics of urban agglomeration. The opening of high speed railway optimizes the city transportation spatial structure fractal characteristics of Yangtze River Delta City Group.