Abstract: Projects of excavation constructions of triple-span arch culvert are simulated using nonlinear finitee element analysis program. After two feasible construction projects are simulated, ground surface settlement, stress change of liner, plastic zone of surrounding soil and so on in the one project are relatively compared with those in the another project. An optimized project is then selected by using fuzzy evaluation after comprehensive consideration. Various risk situations in tunnel excavations are found from the simulation data, which reminds construction unit to adopt relevant provision for the risk area, has achieved high application value and can be used in similar construction for reference.

Key words: superficial layer shading excavation, triple-span arch culvert, side wall pilot culvert, side culvert CRD, project op- timization;