8月7日,历经51h,世界最大海底沉管——港珠澳大桥岛隧工程首段沉管成功浇筑。此次浇筑的海底沉管为E2-S5段,长22.5m,宽37.95m,高11.4m,重约9 000t,浇注混凝土3 281m3,采用两孔一管廊截面形式,具有截面尺度大、预制精度要求高、钢筋预埋件密集、混凝土连续浇筑量大,供应保障级控裂要求高等特点,沉管规模和施工难度均居世界首位。施工中,为确保首节 August 7, after 51h, the largest submarine immersion pipe - Hong Kong-Zhuhai-Macao Bridge Island Tunnel project successfully poured the first tube. The submarine immersed pipe for the pouring is E2-S5 section, length 22.5m, width 37.95m, height 11.4m, weighs about 9 000t, cast-in concrete 3 281m3, using two holes and a pipe gallery cross-section form, High precision requirements, intensive embedded parts of steel, continuous pouring of large quantities of concrete, the supply of high-level crack control requirements, the size of the immersion pipe and the difficulty of construction ranks first in the world. Construction, in order to ensure the first section