基础形式对高填土双孔钢波纹管涵土压力分布规律的影响研究

Research on the Influence of Foundation Type on the Earth Pressure Distribution Law of High Fill Double Hole Steel Corrugated Pipe Culvert

针对不同基础形式的高填土双孔钢波纹管涵的土压力分布特性,依托工程实例通过现场试验结合有限元数值模拟,探讨了不同刚度、圆心角基础形式的涵顶平面填土、涵周土压力分布规律.结果表明:各类基础管涵涵顶平面填土在涵顶沉降最大,土体产生相对滑动,通过摩擦拖拽作用传递荷载,导致涵顶两侧1 m附近垂直土压力最大;随基础刚度提高、圆心角增大,涵顶平面填土不均匀沉降减小,涵顶土压力增大;双孔钢波纹管涵受相邻管涵变形挤压涵间土影响,处于非对称受力状态,靠近管涵一侧径向土压力大于另一侧;基础刚度提高将在填土、基础和管涵三者的接触点引起明显的应力集中,不利于管涵承载,柔性基础协调变形,能够调整土压力分布,使管涵处于较为均匀的环形受压状态.高填方双孔钢波纹管涵应采用圆心角较大且具有良好的变形协调能力的柔性基础,使管涵处于环形受压状态,防止管涵发生失稳破坏,是较为理想的基础选型.

Aiming at the earth pressure distribution characteristics of high-fill double-hole steel corrugated pipe culverts with different foundation forms,relying on engineering examples through field tests and finite element numerical simulation,the culvert top plane filling and culvert circumference with different rigidity and central angle foundation forms,and the law of earth pressure distribution are discussed.The results show that the top plane fill of various types of foundation pipe culverts has the largest settlement on the top of the culvert,the relative sliding of the soil occurs,and the load is transferred through friction drag,resulting in the largest vertical earth pressure near 1 m on both sides of the culvert.With the increase in foundation stiffness,the center angle increases,the uneven settlement of the culvert top plane fills decreases,and the soil pressure on the top of the culvert increases.The double-hole steel corrugated pipe culvert is in asymmetrical stress state that the radial earth pressure on one side close to the pipe culvert is greater than the other side affected by the deformation of adjacent pipe culverts and the compression of soil between the culverts.The increase of the foundation stiffness will cause obvious stress concentration at the contact points of the fill,foundation and pipe culvert,which is not conducive to the bearing of the pipe culvert,and the flexible foundation will coordinately deform which can be adjusted.The earth pressure distribution makes the pipe culvert in a relatively uniform annular pressure state.The high-filled double-hole steel corrugated pipe culvert should adopt a flexible foundation with a large central angle and good deformation coordination ability to make the pipe culvert in a ring-shaped compression state and prevent the pipe culvert from instability and damage,which is an ideal basic selection.