Abstract
The normal dynamic earth pressure acting horizontally on side walls of an underground conduit is investigated with the numerical experiments carried on its 2D-FEM model of which rigidity and unit mass over the cross section are variously changed. The results of these experiments are as follows: 1) The dynamic earth pressure comes of the imbalance of such forces as horizontal shearing and body forces acting on the conduit and its reaction force. 2) The shearing force which the conduit bears is defined as the product of a magnification factor by the shearing force in the ground without structure. This factor is found to be in proportion to the logarithm of non-dimensional shearing rigidity of conduit normalized by the one of ground. 3) The resultant dynamic earth pressure on a side wall is formulated with above factor and forces. 4) Main dynamic earth pressure at any point except for the distributed one of above resultant is found to be in proportion to the difference in displacement between the conduit and the ground without structure.
