An analytical solution for underground structure-country rock dynamic interaction

In this paper according to the results of a great quantity of tests and numerical calculations, it is pointed out that the surrounding rock with thickness of 1/3 span has mechanical characteristics of a thick flexural member in underground rock cave subjected to transverse blast loading. However, it approaches the stress state of free field outside country rock and the equation of thick plate theory under the loading of free field pressure may be applied to the solution of this problem. Therefore, the underground structure-country rock dynamic interaction may be described by dynamic equations of flexural members of thin plate and thick plate, which express linear and country rock respectively. The interaction force between the liner and country rock is expressed as contacting pressure function q(x, l). By solving system of simultaneous equations, the analytical solution for the dynamic analysis of arch-straight liner including elastic half space interaction effect is given and the analytical expression of function q(x, t) is obtained. This analytic solution will contribute to the study of some substantive problems of underground structure-medium dynamic interaction theoretically. (Instutute of Engineering Mechanics, Academia Sinica)