高填方边坡下涵洞受力变形数值模拟

Research on Numerical Simulation of Force and Deformation for Culvert under High Embankment Slope

针对高填方边坡下涵洞的受力变形特征尚无系统研究的现状,结合延安机场超高填方黄土边坡下涵洞工程,运用PLAXIS有限元软件对涵洞周围土压力分布特征和涵体变形规律进行研究。将研究结果与相同工况下的上埋式涵洞进行对比分析,进而得出其受力变形规律,并由此提出实际工程中所需要解决的一些问题。研究结果表明:高填方边坡下涵洞受偏压作用明显,在竖向与侧向上发生了倾斜与偏转;当边坡坡率为1∶2,填方边坡最高点距涵洞中心线水平距离为10倍洞径宽度时,边坡坡面的边界效应开始显现,涵洞受偏压作用;高填方边坡下涵洞涵顶的竖向土压力可参照依其中心线上填土高度所确定的上埋式涵洞的竖向土压力来作为其取值依据。

;Aimed at the present situation that the characteristics of force and deformation of the culvert un- der high embankment slope has not been systematically studied, the distribution characteristics of sur- rounding soils and deformation laws of the culvert are studied by PLAXIS finite element software com- bined with the culvert project under super--high embankment loess slope at Yan＇an airport. Compared the studied results with the positive buried culvert of the same working condition, some laws of force and de- formation are obtained and some problems needed to be solved in the practical project are put forward. The results show that the culvert under high embankment slope is obvious in bias pressure, and incline and de- flection appear in vertical and in lateral direction. The boundary effect of slope appears when the slope ratio is 1 ： 2 and the horizontal distance between the highest point of slope and culvert＇s center line is more about 10 times than the culvert＇s diameter under the action of culvert subjected to the bias pressure. The vertical earth pressure of culvert top under high embankment slope can be referred to earth pressure of positive buried culvert, which is designed by the filling depth of the culvert under slope, and the specific relation ships between them remain to be further studied.