New Method for Designing and Assembling Segmental Cut‐and‐Cover Tunnel Lining in High‐Speed Railway Based on Cross‐Sectional Dimensions

Based on the structural gauge of high‐speed railway and interior contour of high‐speed railway tunnel in which high‐speed trains travel at the velocity from 300 to 350 km/h on double tracks, and considering the characteristics of designing the cross section of arch‐shaped cut‐and‐cover tunnel lining (CCTL) with both curved haunches and invert, the novel formulae to calculate the dimensional parameters of precast segments in CCTL are presented using geometric and trigonometric functions among the arcs and radii of the segments in the cross section of CCTL. In addition, two modes to partition CCTL into segments are proposed to assemble segmental lining of cut‐and‐cover tunnel (CCT) with straight joints. Mode one is the combination of segments in type of 3A + 1B 1 + 1B 2 + 1C’. Mode two is the combination of segments in type of 2A + 1B 1 ’ + 1B 2 ’ + 1B 3 ’ + 1B 4 ’ + 1C’. As such, a novel method to design the precast reinforced concrete segments to assemble CCTL in double‐track high‐speed railway is validated by using a case study. Additionally, the method to assemble CCTL with straight joints and staggered joints is also presented by alternately using the novel segments in Modes one and two. When CCT in double‐track high‐speed railway is to be constructed in cut‐and‐cover foundation trench, optimized C’‐typed precast segment is to be erected initially to form the invert of CCTL, B‐typed segments or B’‐typed segments are to be assembled second to establish the springers of CCTL, and A‐typed precast segments are to be assembled to form the crown and haunches of CCTL eventually.