为了研究沿涵洞纵向不同位置的涵顶竖向土压力的分布规律,基于分布角法推导了距离涵洞口不同位置的涵顶竖向土压力的计算方法.选取图们至珲春高速公路桩号为RK365 +510的高填方涵洞作为试验涵洞,在涵顶埋设土压力盒测量当填土高度为12、16和20 m时,距离涵洞口不同位置的涵顶竖向土压力.分析了竖向土压力沿涵洞纵向的分布规律,探讨了拱效应,分析了基于分布角法推导的土压力计算值和实测值的误差.结果表明,基于分布角法的涵顶竖向土压力的计算和试验结果较接近.离涵洞口较近时,压力盒的应力集中使实测值大于计算值;随着纵向长度的增加,涵顶拱效应使实测值小于计算值.采用规范“土柱法”的计算值偏大造成结构设计过于安全而不经济.建议涵洞可分段设计并采用不同的尺寸.
To investigate the pattern of vertical earth pressure on longitudinal culvert,based on distributing angle method,the calculation method of vertical earth pressure in the different locations in the culvert was deduced.Earth pressure cells were buried on the top of test culvert located in pile number RK365 +510 in Tumen-Hunchun expressway to measure the vertical earth pressure in the different locations in the culvert under the heights of 12,16 and 20 m.The law of the vertical earth pressure in the different locations in culvert was analyzed and the arching effect was discussed.Meanwhile the errors between the calculations with distributing angle method and the measured results were carried out.The results show that the calculations were close to the measured results.When near to the culvert mouth,the testing vertical earth pressure is greater than the calculations due to the stress concentration effect of earth pressure cells ; with the increasing of longitudinal length,the testing vertical earth pressure is less than the calculations because of the arching effect.The result calculated by "soil column method" in code was large.Structure is not cost-efficient because design is too safe.It was suggested that the culvert can be divided into several sections with different size.