深层水泥搅拌桩（DCM）复合地基应用于沉管隧道工程在国内尚无先例，其在沉管隧道工程的适应性、受力特点及布置形式方面有待深入研究。针对深中通道沉管隧道深层水泥搅拌桩（DCM）的合理布置形式，通过建立三维有限元模型，研究出4种不同的布置形式，得出沉管隧道深层水泥搅拌桩（DCM）复合地基的合理布置形式，并开展现场载荷板试验验证。研究表明： 1）深层水泥搅拌桩（DCM）浅层成桩质量较差、桩身强度较低，采用壁式布置时，短桩部分质量难以保证； 2）在置换率相近的条件下，单桩式布置比壁式布置数值计算得到的沉降小，因此深层水泥搅拌桩（DCM）采用单桩式布置较壁式布置优； 3）横纵向桩间距3 m×4 m布置方案的复合地基容许承载力不小于158.3 kPa，横纵向桩间距3 m×3 m布置方案的复合地基容许承载力不小于211.1 kPa，试验结果与三维有限元计算结果规律一致； 4）根据沉管隧道基底荷载的分布模式及载荷板试验，3~5 m不等间距布置方案是深中通道沉管隧道深层水泥搅拌桩（DCM）复合地基最优布置形式。

The utilization of offshore composite foundations with deep cement mixing(DCM) piles in immersed tunnels lacks precedence in China. Further exploration of the adaptability, stress characteristics, and layout forms of DCM piles in immersed tunnels is crucial. Therefore, a case study is conducted on the ShenzhenZhongshan link immersed tunnel. A threedimensional finite element model is employed to assess four distinct layout forms of DCM piles. A rational layout form for DCM piles is indentified and validated through field load plate tests. Key findings include: (1) DCM piles with shallow cover exhibit subpar quality and low strength, while the quality of the short pile section under the bracket layout form cannot be guaranteed. (2) Under similar replacement rates, the simulated settlement of piles with a singlepile layout is smaller than that with a bracket layout. Therefore the singlepile layout is superior for DCM piles. (3) The allowable bearing capacities of the composite foundation, with pile spacings of 3 m × 4 m and 3 m × 3 m, are not less than 158.3 and 211.1 kPa, respectively. These values align well with the calculated results. (4) Considering the foundation load distribution pattern and load plate test results, a variable space DCM pile layout of 3~5 m is preferred for the ShenzhenZhongshan link immersed tunnel.