加筋土桥台承载特性的载荷试验研究

加筋土桥台作为承载结构,其承载力及其影响因素备受关注。以美国鲍曼桥为工程原型,通过大比例缩尺模型的静载试验研究加筋土柔性桥台的承载性能。试验研究中,以有纺土工织物为筋材,共设置3组加筋土柔性桥台模型的载荷试验,主要考察桥梁基座的位置,即桥梁承载区外沿与面板的水平净距对桥台承载力的影响及其变化规律。试验结果表明,水平净距是影响加筋土桥台承载性能的重要因素,承载能力随水平净距的增大而增大,但增幅快速递减;桥台面层水平位移和顶部沉降均随水平净距的逐渐增大而减小,且减小趋势表现出收敛特征;随着水平净距增大,筋材应变极值减小,桥台整体稳定性增强,表现出良好的复合体特性。试验研究结果还表明,美国现行规范关于加筋土桥台承载力计算方法可能仅限于特定的填料和加筋布置方式,因此在工程实践中宜结合工程实际。

Load test study of bearing characteristics of reinforced soil abutments

As a bearing structure, the reinforced soil abutment has attracted much attention for its bearing capacity and its influencing factors. Taking the Bowman bridge as the engineering prototype, this paper studies the bearing capacity of the reinforced soil flexible abutment by the scale model test. In the experimental study, three groups of load tests of the reinforced soil flexible abutment were set up, which uses the geotextile as the reinforcement material. This paper mainly studies the influence of bridge base position on the bearing capacity of the abutment. Test results show that the setback is an important factor affecting the bearing capacity of the reinforced abutment, and that the bearing capacity increases with the setback, but the amount of increase is rapidly diminishing. The horizontal and vertical settlements at the top of the abutment decrease with the increase of the setback, and the decreasing trend shows convergence. With the increase of setback, the maximum strain of reinforcement decreases, and the overall stability of abutment is enhanced, showing better complex characteristics. In addition, the results of this experimental study also prove that the calculation method of bearing capacity of reinforced abutments in the current US regulations may be limited to specific packing and reinforcement arrangement. Therefore, it should be combined with actual conditions in engineering practice.