前言双线铁路当采用自动闭塞、行车间隔时分为8～10min时,平行运行图通过能力可达144～180对,较单线铁路通过能力高2～3倍,是铁路能力最有效的加强措施。新中国成立以来,为适应国民经济的迅速发展,在有计划地发展新线建设和加强改造既有单线铁路的同 Preface The double-track railway when using automatic blocking, the traffic interval is divided into 8 ~ 10min, the parallel operation diagram through the capacity of up to 144 ~ 180 pairs of single-line railway through the ability of 2 to 3 times higher than the railway capacity is the most effective measures to strengthen. Since the founding of New China, in order to adapt to the rapid development of the national economy, it is necessary to develop the new line in a planned manner and to strengthen the transformation of the existing single-line railway