A mathematical programming method for the analysis of the cable-stayed
bridge with unilateral supports is presented. A detailed comparative
study of the nonlinear phenomenon arising from the unilateral restrict
ion at intermediate piers of the bridge is carried out. The characteri
stics of the unilateral supports can be described by a set of control
variables which are of multi-folded constitutive relations with piecew
ise linearity. By using the parametric variational principle, it leads
to the solution of a quadratic programming problem or to a linear com
plementary problem. The distinguished figures of the cable-stayed brid
ge with this kind of support are illustrated by numerical examples.