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南水北调工程穿越黄河砂土地基的输水隧洞，拟采用盾构法施工．本文进行了两类离心模型试验，一类模拟隧洞开挖，一类模拟土—结构相互作用，对穿黄隧洞的开挖稳定问题和土—结构相互作用问题进行了初步的研究．试验结果表明：由于强烈的拱效应作用，隧洞周围的砂土能够在远小于原位土压力的支护压力下保持稳定；当隧洞衬砌与周围上体有一个初始间隙（盾尾间隙）时，土作经过位移和与结构发生相互作用，最后作用在衬砌结构上的土压力远小于原位土压力．
The South-to-North Water Diversion Project crosses the Yellow River sand-conveying tunnel and is intended to be constructed by the shield method. In this paper, two kinds of centrifugal model tests, one type of simulated tunnel excavation and one type of simulated soil-structure interaction, were conducted to study the problems of excavation stability and soil-structure interaction in the tunnel. The test results show that due to the strong arch effect, the sand surrounding the tunnel can be kept stable under a support pressure much smaller than the in-situ earth pressure; when the tunnel lining and the surrounding upper body have an initial clearance (shield tail clearance), The earthwork undergoes displacement and interacts with the structure. Finally, the earth pressure acting on the lining structure is much smaller than the original earth pressure.