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针对用于上海污水外排的黄浦江底隧道工程，通过土工离心模拟试验，探讨了上海粘土的成拱能力。对于无支护的情况，开挖双孔隧道时，洞底以上约８ｍ厚的灰色砂质粉土或粘土中不能形成稳定的天然拱。进一步研究表明，该层土所需的成拱厚度至少为１２ｍ；对于有混凝土管支护的情况，由于支护刚度较大，管顶上土压力基本上等于管顶以上土层的自重应力
In view of the Huangpu River tunnel project used for effluent discharge from Shanghai, the geotechnical centrifuge simulation test was used to discuss the arching ability of clay in Shanghai. For unsupported conditions, a stable natural arch can not be formed in a gray sandy silt or clay of about 8 m above the bottom of a tunnel when excavating a double-bore tunnel. Further studies show that the required arching thickness of this layer of soil is at least 12 m. For the case of concrete pipe support, the soil pressure on the top of the pipe is basically equal to the self-weight stress of the soil layer above the pipe top