求翻译：1、施工步骤：①开挖导坑上半断面 ○Ⅰ上导坑拱部初期支护 ②开挖导坑下半断面 ○Ⅱ下导坑边墙初期支护是什么意思？

1, the construction steps: ① guide excavation pit on the upper section ○ Ⅰ Heading arch supporting the initial pilot tunnel excavation ② half of the next guide section ○ Ⅱ initial support wall Kengbian

Step 1 : 1, construction digging up Anti-Ballistic Missile hang half 0 sessile I arch of the Hsuehshan initial support care 2dig Hsuehshan sessile half under the Hsuehshan II 0 wall support early care

1st, construction steps:①Excavates in the guiding hole half cross section ○ⅠOn the guiding hole arches the initial period supports and protections ②Excavates the guiding hole next half cross section ○ⅡNext guiding hole frontier wall initial period supports and protections

1, construction steps: ① excavation on the upper section of the drift 0 ⅰ heading excavation of arch primary supporting ② heading lower heading under the section 0 ⅱ sidewall early support

1st, construction steps:①Excavates in the guiding hole half cross section ○ⅠOn the guiding hole arches the initial period supports and protections ②Excavates the guiding hole next half cross section ○ⅡNext guiding hole frontier wall initial period supports and protections