中文摘要：

文章对现有沉管隧道竖向沉降计算中采用的弹性地基梁法进行了修正，改进了对半柔半刚性接头的约束方式，提出了地基弹性抗力系数K的计算方法；建立了砂基础层的沉降计算方法，并提出采用土体回弹模苗计算地基土层沉降；以浙江舟山沈家门港海底沉管隧道工程为例，分别计算了正常工况和极限工况下沉管隧道产生的竖向沉降。算例分析结果表明：本方法可以较好地反映土层不均匀、回淤不均匀和不同接头形式对沉管隧道竖向沉降的影响，计算结果与实测值比较接近：沈家门港海底沉管隧道基础层产生的沉降较大，占总沉降的比例超过50％；不同的M端接头形式，对沉管隧道竖向沉降分布的影响非常大。

英文摘要：

In this paper, the elastic foundation beam method currently used in the vertical settlement calculation for immersed tunnels is modified, the restricted method of semi-flexible and semi-rigid joints is improved, the calculation of foundation elastic resistance coefficient K is put forward, the settlement calculation for sand founda- tions is established, and a soil mass rebound modulus is proposed to calculate foundation settlements. Using the construction of the Shengjiamengang immersed tunnel in Zhoushan of the Zhejiang Province as an example, the vertical settlements of an immersed tunnel under normal conditions and limited conditions were calculated respectively. The results show that： the given method can reflect well the effects of an uneven soil layer, uneven siltation, and different joint forms on the vertical settlement of immersed tunnels; the calculated results are close to the measured ones; for the Shengjiamengang subsea tunnel, the settlement in the foundation is relatively large, being more than 50% of the total settlements; and different joint forms at both ends have great influence on the vertical settlement distribution of immersed tunnels.