be used to guide the deflection of the tendons which results from variations in the load on the cables on the interior side of the curvature of the path t the widening of the cross section of the conduit 10 can follow a generatrix whose shape is preferably circular with a radius r u2032 that is less than the radius of curvature r of the path t in the central portion of the conduit 10 the fact that the radius r u2032 is constant enables the bending stresses to which the tendons 4 are subject to be limited the widening of the cross section of the conduit 10 at both ends may result from a homothetic transformation of the shape shown in fig4 a variant consists in gradually enlarging outwardly the interior portion of the section of the conduit so that it tends toward the circle of radius r u2032 along the outer face of the saddle 5 another variant consists in putting on either side of the central portion of constant section of the conduit 10 a trumpet shaped widening of circular cross section whose smallest diameter is equal to r u2032 in this way the widening can be simply realized with a machined guide piece placed in the opening of the conduit 10 the central portion of the conduits 10 can be realized by being molded in the material 7 e g filler mortar constituting the matrix of the saddle 5 in this way.