Limit states behaviour and modeling of deep corrugated steel box culverts

金属涵洞结构的强度和刚度取决于金属和土壤成分的组合特性。虽然已经做了大量工作来了解正常运行负荷(预计在使用中的地球和车辆负荷)下的负荷分担的性质，但对于LOAC水平接近崩溃时的行为、复合系统的不同部件如何达到其强度极限以及如何将负荷从处于困境的部件重新分配到仍具有备用能力的其他部件，人们知之甚少。由于不可能进行导致这些结构失效的实验，因此不可能观察到这种非线性反应并在计算机上自信地对其进行建模。因此，现有的金属涵洞强度理论假定，倒塌时构件之间的荷载分担与服役荷载下的荷载分担是相同的。此外，加拿大制造的深波纹金属箱形涵洞是一种重要的涵洞类型，迄今尚未包括在计算机模拟研究中，这些研究构成了目前加拿大和美国涵洞设计实践的基础。

The strength and stiffness of metal culvert structures depends on the composite behaviour of both the metal and soil components. While considerable work has been performed to understand the nature of load-sharing at normal operating loads (the earth and vehicle loads expected in service), little is known about behaviour at loac levels approaching collapse, how the different components of the composite system reach their strength limits, and how loads are redistributed from components in distress to others that still have reserve capacity. Since it has not been possible to conduct experiments that bring these structures to failure, it has not been possible to observe this nonlinear response and model it confidently on the computer. Current theories of metal culvert strength therefore assume that load sharing between the components at collapse is identical to load sharing at service loads. Furthermore, deeply corrugated metal box culverts manufactured in Canada are an important culvert type that has not been included in the computer modeling studies performed to date, which form the basis of current Canadian and US culvert design practice.