为解决传统明挖法、矿山法、盾构法和顶管法在综合管廊施工中存在的不足和局限，根据国内管廊工程建设环境特点，通过分析传统管廊施工方法的优点和不足，结合装配式建筑的发展趋势，创新性地提出U型盾构机械化施工工法。该工法将明挖法开挖与在盾壳内完成主体预制拼装结构相结合，通过研制相应装备将传统固定支护结构转变为刚性可移动支护结构，实现了明挖法管廊施工的机械化、标准化和规范化。介绍U型盾构工法的原理、适用范围、工艺流程、操作要点和节点处理，对比U型盾构与传统明挖支护结构的受力特点和对周边环境的影响，分析U型盾构适用范围及其工法优势； 通过海口市椰海大道管廊试验，验证了该工法在明挖综合管廊施工中具有较高的进度优势、经济优势和推广应用价值； 最后探讨该工法在小曲线半径、矩形或U型断面工程以及明挖框架结构工程中的应用前景，以期为综合管廊及类似工程提供一种新的设计理念和施工工法。

There are limitations in utility tunnel construction by traditional methods such as cutandcover method, mining method, shield tunneling method and pipejacking method. In this paper, innovative Ushaped shield mechanized construction methods are put forward according to the characteristics of domestic utility tunnel construction environment, by analyzing the advantages and disadvantages of traditional utility tunnel construction methods and development trend of prefabricated construction. The abovementioned method combines the advantages of prefabricated assembly technology in shield tunneling method with the cutandcover method, and transforms the traditional fixed support structure into a movable rigid support structure by corresponding equipment; and hence, the mechanization and standardization of the construction of utility tunnels are realized. The principle, applicable scope, process and operation keys of the Ushaped shield construction method are introduced. The force characteristics of Ushaped shield and traditional cutandcover support structure and their influences on the surrounding environment are compared; and the applicable scope of Ushaped shield and its advantages are analyzed. And then the test results of method in utility tunnel on Yehai Avenue in Haikou verify the superiority of the method in terms of schedule, economy and popularizing value. Finally, the applicable prospect of the method in the field of small curved radius, rectangular or Ushaped crosssection and the frame structure of cutandcover method is discussed, so as to provide a new design idea and construction method for the utility tunnel and similar projects in the future.