首先阐述盾构始发和到达端头加固的目的，在简要介绍端头加固计算方法和设计现状后，对端头加固计算方法和设计现状存在的问题进行了详细论述，并结合不同地层情况对端头加固的合理范围进行了分析，认为盾构始发和到达端头加固范围应根据其端头的具体地层情况和盾构设备长度以及土体强度、稳定性等验算结果来综合确定。通过研究进一步明确端头加固的目的、作用和意义，为确定不同条件下盾构始发和到达端头合理加固范围提供参考。

With the introduction of the purposes of strata improvement for EPB TBM driving at its start and arrival, and the presentation of calculation method and design situation of strata improvement, the authors discuss the problems in calculation method and design situation for strata improvement in detail. Furthermore, they analyse the reasonable strata improvement scopes at the start and arrival of EPB TBM in various strata, and put forward their standpoint on strata improvement scopes determination. The strata improvement scope for EPB TBM driving at its start and arrival should be determinated in accordance with the strata situation, length of shield machine and strength and stability of ground. This paper gives a further definition of the purposes, effects and significance of strata improvement and can provide references for reasonable strata improvement scopes for shield driving at its start and arrival in different strata.