⏺13-9 某I级铁路上一变坡点处的纵断面图如下图所示,变坡点A的设计高程为123.45m,试求Tsh、Lsh及竖曲线上每20m的施工高程(即图中1,2,3,…,7各点)。0‰12‰

解:由题意,I级铁路,RSH=10000m,TSH==5×12=60(m)

竖曲线长度LSH=2 TSH=120(m)

外矢距ESH==0.18 (m)

1点的施工高程为:HA-TSH×12‰=123.45-60×12‰-0=122.73 (m)

2点的施工高程为:HA-(TSH-20)×12‰-=123.45-40×12‰-0.02=122.95 (m)

3点的施工高程为:HA-(TSH-40)×12‰-=123.45-20×12‰-0.08=123.13 (m)

4点的施工高程为:HA-ESH=123.45-0.18=123.27 (m)

5点的施工高程为:HA-=123.45-0.08=123.37 (m)

6点的施工高程为:HA-=123.45-0.02=123.43 (m)

7点的施工高程为:HA-0=123.45 (m)