【摘要】 占压导致地基下沉和管道变形。建立了地基-管道的三维有限元模型,分析占压载荷作用下管道的应力与变形。模型考虑了管-土间的相互作用和管底夯实地基,符合占压管道的实际载荷情况。结果表明:管道在上覆土体和夯实地基的不均匀作用下发生局部弯曲和椭圆化变形;上覆土体越软,管道变形越大,管底夯实地基起到阻止管道下沉的作用,二者弹性模量相差越大,管道在夯实地基边缘处的环向弯曲应力越高;内压起到抵抗管道变形的作用,但其影响程度较小;薄壁大口径管道的应力水平和变形程度相对较高,上覆土体对大口径管道横截面变形有较大的约束作用;占压载荷与管道横截面的椭圆化变形率近似呈线性关系,依据极限椭圆化变形率可以确定管道所能承受的安全占压载荷。更多还原

【Abstract】 Surface load results in foundation settlement and pipeline deformation.A numerical analysis of the stress and deformation of buried pipeline subject to surface load was performed using a 3D finite element model of pipeline-foundation system considering pipe-soil interaction and tamping foundation.The results show that surface load induces local bending and ovalization of pipeline due to non-uniform effects of overlying soil and tamping foundation.Softer overlying soil has greater influence on pipeline deformation;the main effect of tamping foundation is to resist pipeline settlement,and the greater the differential value of elastic modulus between overlying soil and tamping foundation,the greater the bending stress of pipeline at the edge of tamping foundation.Internal pressure has a little effect to resist pipeline deformation.High stress and deformation occur in a pipeline of thinner wall or larger diameter,and overlying soil has much effect to restrict ovalization of such a pipeline.Pipeline ovalization increases approximately linearly with surface load.Allowable surface load may be determined according to ovalization of pipeline.更多还原