水下长距离顶管是直接在地下水位以下的土层中长距离顶进管道的一种施工方法。采用这种方法敷设管道无须挖槽或在水下开挖土方,并可避免为疏干和固结土体而采用降低地下水位等辅助措施,从而大大加快了施工进度,降低造价,并能克服在穿越江河、通向湖海等无法降水的特殊环境下施工的困难。一个世纪前“顶管法”问世以来,其独特的优越性使该施工方法在世界许多国家中被广泛应用。“长距离顶管法”从理论上讲是一种顶进距离不受限制的施工方法。采用这一方法,在美国1980年曾创造9.5小时顶进 Underwater long-distance pipe jacking is a method of constructing long-distance jacking into a pipeline in a soil layer below the water table. Pipes laid in this way do not require trenching or excavation of earth under water, and can avoid the use of auxiliary measures such as lowering the groundwater level for draining and consolidating soil, which greatly speeds up the construction schedule, reduces the cost, and can overcome Difficulty in construction under special circumstances such as crossing rivers and leading to lakes and seas where precipitation is impossible. Since the advent of the “pipe jacking method” a century ago, its unique superiority has made this construction method widely used in many countries in the world. The “long distance pipe jacking method” is theoretically a construction method with unlimited jacking distance. Using this method, in the United States in 1980 created 9.5 hours into the top