以某铁路枢纽配套工程新建客线为背景。货线已沿坡脚间隔设置桩板式挡土墙，新建客线左线需拆除货线，在原位置修建左线，并在右侧位置增建右线，由于用地宽度有限，需在既有支挡工程范围以内设置支挡工程收坡。于里程内6根既有桩桩顶设高1.20 m、宽2.0 m、长31.5 m的冠梁，用既有桩板墙增加冠梁这种新旧支挡结构，联合支挡新建的客线荷载，运用MIDAS GTS-NX有限元软件，研究在货线作用下和拆除货线新建客线作用下既有桩的受力特性对比分析。既有桩的墙背土压力增大幅度不明显，桩身最大剪力出现在距离桩顶2 m位置，桩身最大弯矩出现在距离桩顶4 m位置。
The background is the new passenger line of a railway hub supporting project. Pile and plate retaining wall has been set up along the foot of the freight line. The left line of the new passenger line shall be dismantled, the left line shall be built at the original position, and the right line shall be added at the right position. Due to the limited width of the land, the slope of the retaining project shall be set up within the scope of the existing retaining project. Crown beams of 1.20 m in height, 2.0 m in width and 31.5 m in length were set at the top of six existing piles within the mile. The existing pile slab wall was used to add the new and old retaining structure of crown beam, and the newly built passenger line load was combined with the newly built passenger line load. MIDAS GTS-NX finite element software was used to study the comparative analysis of the stress characteristics of the existing piles under the action of cargo line and the action of the newly built passenger line when the cargo line was removed. The increase of soil pressure on the wall back of the existing pile is not obvious. The maximum shear force of the pile appears 2 m away from the pile top, and the maximum bending moment of the pile appears 4 m away from the pile top.
