为明确沉管隧道干坞深大基坑开挖格形连续墙的力学响应特征，以典型工程实例为依托，借助有限元软件建立基坑开挖支护的三维计算模型，揭示格形连续墙的力学特性，开展方案评价及优化，探索格形连续墙变形对不同影响因素的敏感性。研究结果表明： 1）实例基坑2种支护形式衔接处位移存在明显的突变，有必要对原有支护方案衔接位置局部加强； 2）格形连续墙阳角两侧均向坑内移动，导致盖板阳角处出现了明显应力集中，诱发结构局部开裂且发展，存在渐进破坏的趋势； 3）对应力集中的局部区域，增加预埋受拉钢筋，以抑制裂缝的形成与扩展； 4）格形连续墙变形受盖板厚度的影响较为明显，但受墙内搅拌桩加固范围的影响很细微； 5）随墙间连接接头刚度的折减，格形连续墙围护结构整体空间刚度减小，位移逐渐增大，当刚度减小到一定程度时趋于稳定。

In order to clarify the mechanical response characteristics of cellular diaphragm wall for drydock foundation pit excavation of immersed tunnel, a threedimensional calculation model is established by the finite element software based on a typical engineering example. The mechanical characteristic of cellular diaphragm wall is revealed. The support scheme evaluation and optimization are carried out, and the sensitivity of deformation to different influencing factors are explored. The results show that: (1)Displacement catastrophe occurs at the joint between the two support forms in the foundation pit, so it is necessary to strengthen the joint on the basis of the original support scheme. (2)Positive angle on both sides of the cellular diaphragm wall move toward to the pit, which results in obvious stress concentration at the positive angle of the cover plate and local cracking with a tendency of gradual failure. (3)Add tensile steel bars at the stressconcentrated region so as to restrain the formation and expansion of crack. (4)Deformation of cellular diaphragm wall is obviously affected by the thickness of cover plate, while it is slightly affected by the reinforcement range of the mixing pile. (5)With the reduction of joint stiffness between walls, the overall space stiffness of cellular diaphragm wall decreases, and the displacement increases gradually. When the stiffness decreases to a certain extent, it tends to be stable.