MODEL TESTS ON INFLUENCES OF STIFFNESS AND SPACING FOR BEAMS ON LATTICE BEAMS BY PRESTRESSED ANCHORAGE

Through model tests of interaction between lattice beams by prestressed anchorage with different cross sections and spacing of beams, the earth pressure, the strain of rebars in lattice the beams and the tension forces of the anchors were measured, and the influences of the stiffness and spacing on the bottom reaction of lattice beams, the internal forces of lattice beams and tension forces of anchors were analyzed. The results showed that when the stiffness of lattice beams was larger, the reaction on beams was more uniform, the tension forces of the anchors and the deformation of lattice beams were also more uniform, the strain of lattice beams was smaller, while the bending moment in the beams was larger. When the stiffness of lattice beams was the same, the larger the spacing, the greater the difference of tension forces in anchors, the smaller the base reaction, the worse the uniformity of the reaction, and the larger the bending moment of beams. When the amounts of spans were more, the bending moment was smaller.