【摘要】 为了克服大型沉井设计和施工控制中存在的问题,对大型沉井侧壁摩阻力的计算模式进行了研究.根据马鞍山长江大桥南锚碇沉井侧壁土压力的现场监测数据,反推出不同下沉深度条件下沉井侧壁摩阻力的统计结果,并研究了大型沉井下沉期侧壁摩阻力的分布特征.分析结果显示:当沉井下沉深度小于某一特定深度H0时,井壁侧阻力基本上随着入土深度呈线性增长;而当沉井刃脚入土深度大于H0时,沉井侧壁摩阻力分布呈现上下小、中间大的分布,上部可近似为线性段,下部则近似为双曲线段;而且随着沉井入土深度的不断增加,沉井侧壁摩阻力峰值基本呈线性增长,且峰值发生的位置也逐渐下移.最后,建立了一种大型沉井侧壁摩阻力的修正计算模式.与现场实测数据的对比结果表明,所提出的修正计算模式是可行的.更多还原

【Abstract】 To overcome the problems in design methodologiesand construction control measures for the large open caisson,systematic research was conducted on the side friction calculation mode of the large open caisson. Based on the field monitoring data of lateral soil pressure on the side wall of the open caisson for the southernanchorage of the Maanshan Yangtze River Highway Bridge, the statistical result of the side friction under different buried depths of the cutting edge of the open caisson was back-analyzed;and the side friction distribution of the large open caisson was underlined. Theanalysis results indicate that w hen the buried depth of the cutting edge is smaller thana certain depth H0, the side friction linearly increases w ith the increase in the buried depth.How ever,as the buried depth of the cutting edge is larger than H0, the side friction show sa distribution w ith smallat both endsand large in the middle. The top of the distribution can be regardedasa linear curve, w hile the bottomasa hyperbolic curve. As the buried depth of cutting edge increases continuously, the peak value of the side friction linearly increasesand the location of the peak value gradually moves dow n. Based on theaforementioned conclusions,a revised calculation mode of the large open caisson is presented. Then,the calculated resultsare compared w ith the field monitoring data, w hich verifies the feasibility of the proposed revised calculation mode.更多还原