山区高填方盖板涵涵顶应力集中影响因素研究

Study of the Factors Affecting the Top Stress Concentration of Slab Culvert on High Filled Section in Mountainous Area

高填方涵洞受力机理复杂,现行规范未能综合考虑山区中众多因素对涵顶垂直土压力的影响,致使高填方涵洞易出现不同程度的病害。为探明山区中多种因素对高填方盖板涵涵顶应力集中的影响,基于前期调研和数值仿真分析,研究了填土高度、结构尺寸、填土模量、地基土模量及地形条件对盖板涵涵顶垂直土压力集中系数Ks及涵顶内外差异沉降δ的影响,在此基础上提出相应的工程技术建议。研究结果表明:Ks与涵身跨径、涵顶侧填土模量、地基土模量及沟坡坡度呈负相关,与涵底地基土模量、沟坡宽度呈正相关,与填土高度的关系呈先增大后减小最终趋于稳定的变化趋势;Ks与δ关系密切,但并非呈简单的线性关系。根据研究结果,提出了利用现场地形条件及改进施工工艺减轻高填方涵洞涵顶应力集中现象的工程建议。

The mechanism of high fill culverts is complicated,and the current codes fail to take account of the influence of many factors on the vertical earth pressure of culverts,which results in different degrees of defects of high fill culverts.In order to find out the factors affecting the stress concentration on the top of slab culvert in mountainous area,based on investigations and numerical simulations and analysis,studies are carried out in terms of the impact of embankment height,structure size,soil modulus,soil modulus and topography on vertical earth pressure on the top of culvert concentration coefficient Ksand inner and outer of the culvert differential settlementδ.On the basis of the corresponding engineering technical advice is put forward.The results show that the Ksis negatively related to the top of the culvert span,side fill modulus,earth foundation modulus and gully slope,and is positively correlated with the culvert bottom soil modulus and the gully width,and increases first,then decreases and finally tends to be stable against the filling height;Ksandδare closely related,but not be in a simple linear relationship;and the recommendation that using terrain conditions and improving the construction process to reduce the high embankment culvert stress concentration is proposed.