CONSTRUCTION METHOD OF UNDERGROUND CONSTRUCTION AND UNDERGROUND CONSTRUCTION

PROBLEM TO BE SOLVED: To shorten a construction period.SOLUTION: A construction method of an underground construction comprises: a shield tunnel construction process for constructing a plurality of shield tunnels 11 between one end part 1a and the other end part 1b of an underground construction scheduled region in a peripheral direction; an outer shell skeleton construction process for constructing an outer shell skeleton 12 which is formed by connecting the plurality of shield tunnels 11; and an excavation process for forming an underground cavity 4 by excavating an internal peripheral side region of the outer shell skeleton 12. In the shield tunnel construction process, a full-length shield tunnel 13 is extended up to the other end part 1b, and a cross section area of the outer shell skeleton scheduled region 12A is reduced toward the other end part 1b from one end part 1a without extending a short-length shield tunnel 14 up to the other end part 1b.SELECTED DRAWING: Figure 1 【課題】工期の短縮を図る。【解決手段】地下構造物予定領域の一方端部１ａと他方端部１ｂとの間に複数のシールドトンネル１１を周方向に構築するシールドトンネル構築工程と、複数のシールドトンネル１１を連結してなる外郭躯体１２を構築する外郭躯体構築工程と、外郭躯体１２の内周側領域を掘削して地下空洞４を形成する掘削工程と、を備え、シールドトンネル構築工程では、全長シールドトンネル１３を、他方端部１ｂまで延伸し、短尺シールドトンネル１４を、他方端部１ｂまで延伸せずに、外郭躯体予定領域１２Ａの断面積を、一方端部１ａから他方端部１ｂに向けて小さくする。【選択図】図１