Elasto-plastic solution for cold-regional tunnels considering the compound effect of non-uniform frost heave, supporting strength and supporting time

摘要

The influence of accurate evaluation of frost heave on tunnel safety plays an important role in construction technology and measures to prevent frost damage of cold-regional tunnels. To propose new theoretical insights for the analysis and design of tunnels in cold region, a new calculation model that considers the effect of non-uniform frost heave is established. During the analysis process, according to the supporting strength and supporting time, this calculation model is subdivided into three cases: (1) r(p) r(L); (2) r(L) r(p) r(f); (3) r(p) r(f). An engineering example is studied to derive the stresses and deformation of the lining and surrounding rock of cold regional tunnels. By comparing the stress distribution and the plastic damage radius for the epsilon(0) value of 0 and 0.0055, it is revealed that frost heave does not promote the development of the plastic zone but increases the stress difference in lining, which is one of the main reasons that leads to the instability of tunnels in a cold region. Finally, the influence of the supporting strength, supporting time and initial ground stress on the plastic damage radius and the stress acting on the lining is studied. The calculation method and results can provide a guide for the construction of cold-regional tunnels.