中文摘要：

在长江下游这种冲淤较大的河床上修建过江隧道,最大冲深是工程设计的关键参数之一。本文以长江下游南京河段拟建纬三路过江隧道为例,对最大冲深的确定方法开展探讨。首先针对研究河段来水沙特点,充分考虑三峡水库的影响,从工程安全角度出发,提出了水沙条件的确定方法,并确定了不利水沙条件;在此基础上,采用平面二维水沙数学模型,对工程位置的河床最大冲深进行模拟计算,并与物理模型试验结果进行对比,对比分析表明二者结果较为一致;最后,考虑三峡上游水库运行的影响,对以上结果进行了修正,并与地质勘测资料进行对比,结果表明以上方法确定的最大冲深是合理的,对工程而言是偏安全的,可为过江隧道的合理埋设提供科学依据。

英文摘要：

Maximum bed erosion depth near the location of a crossing tunnel under the lower reach Yangtze River of high aggradation and degradation rates is a key parameter of tunnel design,and its prediction method is discussed in this paper through a case study of the Weisanlu tunnel that is to be constructed in Nanjing.A method of calculating the flow and sediment series is proposed with consideration of the affects of the Three Gorges reservior＇s operation and the incoming flow and sediment conditions of the studied river reach,and the adverse conditions are determined to meet the project safety needs.A two dimensional numerical model is used to predict the maximum erosion depth,and its calculations agree well with the measurements in a scale model test.The simulated result is modified against the affects of the reservoir operation,and compared with the survey data of river bed drilling.The predicted maximum erosion depth by the proposed approach is shown reasonable and safe for design of the tunnel,and it would be a scientific basis for the design.