Prestressing introduction manner null to angle of skew prestressed box culvert and angle of skew box

摘要

PURPOSE: To enable prestress introduction in the oblique direction without changing the basic form of the side wall surface of an oblique box culvert and without requiring any wedge by forming jack reaction surfaces crossed at right angle to the arrangement direction of tensions in the recessed parts of side wall inner surfaces at tensioned end surface parts. ;CONSTITUTION: Four PC steel materials P1 to P4 are arranged as tensioning material on the top plate 2 and bottom plate 3 of an oblique box culvert 1 with inclination on one side. Also the uppermost PC steel material P1 is made in parallel with an axis crossed at right angle to the outer surface 4a of a side wall 4, steel material P2 is inclined by an angle of α, and steel materials P3 and P4 are inclined by angles of β and γ, respectively. Then the bottom surfaces of recessed parts 6a to 6d are crossed at right angle to the axes of the PC steel materials, respectively, and anchor plates 8a to 8d are attached to them, respectively. When the top end part of a jack is inserted into the recessed parts 6a to 6d and the flat surface of its top part is made in contact with the surfaces of the anchor plates 8a to 8d, the axis of the jack 10 coincides with that of each PC steel material. Under this condition, the jack 10 is operated to tense each PC steel material using the surface of each anchor plate as a reaction surface.;COPYRIGHT: (C)1996,JPO