Abstract
This study dealt with uncertainties of external loads on the structural system by using probabilistic principal component analysis that was included in multivariable analysis. In this method, we can compute several eigen values and eigen vectors that were derived from phenomenon of between vertical displacements and horizontal one of each node of structural system on orthogonal coordinate system. From computing results throughout random simulations, we can clarify that first principal component of vertical direction implies tendencies of movement of external load with same direction. Moreover, we can confirm that first principal component of fluctuation based on vertical direction is also coincident with second principal component of one based on horizontal direction. And the opposite case between second principal component of vertical direction and first principal component of horizontal one can be composed. We can expect that these tendencies may be useful for both probabilistic and deterministic optimum design from now.
