高填方钢波纹管涵土-管共同作用测试与分析

Test and Analysis on Soil-pipe Interaction of High-filled Steel Corrugated Pipe Culvert

为了探究高填方大跨钢波纹管涵变形、应力和土压力特征以及土-管共同作用的机理和影响因素,对一座双孔高填方大跨钢波纹管涵进行了试验测试。提出了考虑土体及土-管接触非线性特性的有限元建模方法。综合考虑管涵直径、波形尺寸及多管效应对土-管共同作用及土压力分布的影响,提出了管内对拉钢索控制管涵变形和应力的施工措施,对管顶铺设EPS板的减荷效果进行了数值模拟。结果表明:ANSYS有限元模型充分地考虑了土体与土-管接触的非线性特性,计算结果较为精确,钢波纹管涵变形、应力与径向土压力的计算结果与实测结果相吻合,变化趋势基本一致,径向土压力计算结果与实测值最大误差只有12.48%左右;管涵几何参数(管涵直径、波形尺寸)对钢波纹管涵受力特性影响显著;多管效应对钢波纹管涵土压力分布影响显著;管顶竖向土压力在高填方回填土中受土-管共同作用影响显著,随着填土高度增加,土-管共同作用引起的整体土拱效应经历了先负向增长再正向增长的过程,并在临界高度时达到土拱效应最大负向化;在填土完成后去除管内对拉钢索,变形最大减小46.65%,最大等效应力减小约9%;管顶铺设厚度为0.2 m的EPS板,管涵变形、应力及土压力都显著减小,管顶仅需承担46.85%的上方土体自重。

In order to explore the deformation,stress and soil pressure characteristics of high-filled long-span steel corrugated pipe culvert and the mechanism and influencing factors of soil-pipe interaction,an experimental test on a double-hole high-filled long-span steel corrugated pipe culvert is carried out.A finite element modeling method considering the nonlinear characteristics of soil and soil-pipe contact is proposed.Comprehensively considering the influence of pipe culvert diameter,waveform size and multi-pipe effect on the soil-pipe interaction and soil pressure distribution,the construction measures to control the deformation and stress of pipe culvert by pulling steel cables inside the pipe are proposed,and the load reduction effect of EPS plate on pipe top is numerically simulated.The result shows that(1)The ANSYS finite element model fully considers the nonlinear characteristics of soil and soil-pipe contact,and the calculation results are relatively accurate.The calculated result of deformation,stress and radial earth pressure of steel corrugated pipe culvert is consistent with the measured result,and the variation trend is basically the same.The maximum error between the calculated result of radial earth pressure and the measured value is only 12.48%.(2)The pipe culvert geometry parameters(pipe culvert diameter,waveform size)have obvious influence on the mechanical characteristics of steel corrugated pipe culvert.(3)The multi-tube effect has obvious influence on the soil pressure distribution of corrugated steel pipe culvert.(4)The vertical earth pressure at the top of the pipe is obviously influenced by the soil-pipe interaction in the high-filled backfill,with the increase of the filling height,the soil arching effect caused by the soil-pipe interaction experienced a process of negative growth first and then positive growth,and reached the maximum negative effect at the critical height.(5)After the completion of filling,the tensioned steel cable in the tube is removed,the maximum deformation is reduced by 46.65%,and the maximum equivalent stress is reduced by about 9%.(6)The EPS plate with a thickness of 0.2 m is laid on the top of the tube,the deformation,stress and earth pressure of pipe culvert are significantly reduced,and the top of the tube only needed to bear 46.85%of the dead weight of upper soil mass.