中文摘要：

为了确定单箱双室箱梁有效翼缘宽度的取值,分别按照中国现有规范中对单箱单室箱梁以及美国AASHTO规范中对单箱多室箱梁有效翼缘宽度取值的规定,对箱梁的刚度进行折减并建立梁格模型。为了对比刚度折减精度,采用有机玻璃模型进行实测研究,建立基于实体单元的有限元数值模型。通过对比不同模型在集中荷载作用下的竖向变形和纵向应力可知,按中国规范刚度折减后的挠度值与试验值相对误差为-4.4%,按美国规范则为4.8%,按中国规范刚度折减后的梁格峰值应力与实体单元数值模拟值的相对误差为-25.0%,计算结果偏小;按美国规范则为-7.2%,在10%以内。当计算单箱双室箱梁的应力时,建议按美国AASHTO规范进行刚度折减。

英文摘要：

In order to get the effective flange width of single-box double-cell box girder, based on the code for effective flange width of single-box single-cell box girder in our country and that of single-box multi-cell box girder in American（AASHTO） , the stiffness of the box girder was reduced and a beam-gird model was established in this paper. In order to compare the accuracy of stiffness reduction, an organic glass model was used for experimental study and a finite element model based on the solid element was established. Through the comparison of the vertical deformation and the longitudinal stress of different models under the action of concentrated load, according to Chinese code, the relative error between the deflection value and the measured value is -4.4%, according to American code, the relative error is 4.8%. According to Chinese code, the relative error between peak stress of beam-grid model and numerical value of solid model is -25.0% , the calculation result is small. According to American code, the relative error is -7.2% ,which is less than 10%. The AASHTO code is recommended to reduce the stiffness when calculate the stress of single-box double-cell box girder.