Analytical solutions for rheological processes around bores and tunnels

Five analytical solutions are presented for processes of linear viscoelastic, homogeneous, and isotropic solids around freshly opened bores / tunnels in various initial stress fields. The solutions are obtained via a simple and direct realization of Volterra’s principle. This realization is based on an appropriate decomposition of the known solution of the corresponding elastic problem and leads to ordinary differential equations in the time variable in the viscoelastic case. Fairly rich temporal behaviors are revealed.