multi-arch dam连拱坝
multi-arch tunnels连拱隧道
multi-arch bridges连拱
multi-arch beam拱梁分载
multi-arch bridge多跨拱桥
multi-arch tunnel连拱隧道
double multi-arch双连拱
double multi-arch tunnel双连拱隧道
Foziling multi-arch dam佛子岭连拱坝