symmetrie balanced incomplete block design

The flag-transitive and primitive automorphism groups of ( v, k ,3)- symmetric designs;

(v,k,3)-对称设计的旗传递本原自同构群

The feasibility is proved by theory,which is instructive for the unsymmetrical design on initial support structure of double-arch tunnel in partial pressure.

依托江西景婺黄(常)高速公路白洋冲一号隧道工程,采用数值模拟方法对偏压连拱隧道在Ⅴ级围岩浅埋段初期支护结构进行了优化分析,从理论上证实了偏压连拱隧道初期支护结构不对称设计的可行性。