求高手解读命令流，谢谢！

********************从15+12m处开始开挖与支护
*Step,name=Step-11,NLGEOM=YES
*Soils,consolidation
3600,3600
*MODEL CHANGE,REMOVE
st-excavation-14,st-clayfortuguan-14,st-clayforlining-14
TUGUANSUPPOT14
*MODEL CHANGE,ADD
TUGUANSUPPOT14
TUGUANSUPPOT11,LININGSUPPOT11
*End Step
********************从15+13m处开始开挖与支护
*Step,name=Step-12,NLGEOM=YES
*Soils,consolidation
3600,3600
*MODEL CHANGE,REMOVE
st-excavation-15,st-clayfortuguan-15,st-clayforlining-14
TUGUANSUPPOT15
*MODEL CHANGE,ADD
TUGUANSUPPOT15
TUGUANSUPPOT12,LININGSUPPOT12
*End Step