Surface notches lower the stiffness of laminated strips, so they lower the buckling loads of the laminated strips, too. In this paper a new method is proposed to predict the buckling loads of the laminated strips with...Surface notches lower the stiffness of laminated strips, so they lower the buckling loads of the laminated strips, too. In this paper a new method is proposed to predict the buckling loads of the laminated strips with a surface notch. The theoretical and experimental results show that the buckling loads decrease as the depth or width of the surface notches increase; when the stacking sequence of the laminated strips is [0°/0°/+ θ/-θ/0°/0°/+θ/-θ] s , the buckling load decrease as θ increases. It proves that the method is reliable and significant.展开更多
The paper presents examples of technological designs for concrete placement in road bridges constructed during the S5/S 10 expressway extension in Poland. The project included eight concrete or composite bridge struct...The paper presents examples of technological designs for concrete placement in road bridges constructed during the S5/S 10 expressway extension in Poland. The project included eight concrete or composite bridge structures with different numbers of decks. The concrete placement technology is presented for the following bridge decks： slabs cast-in-situ, composite with precast or VFT （prefabricated composite beam） beams and mixed with cast in situ slabs and VFT-WIB （filler beam） beams. Continuous concrete placement was adopted for almost all the bridge superstructures except the mixed-type decks where construction joints were necessary. To control shrinkage, formwork deformations and existing restraints, the concrete was poured in layers and in stages. The design pace of concrete placement was moderate to be regulated at site without compromising safety and quality. The placement methods enabled both efficient and safe concrete pours.展开更多
文摘Surface notches lower the stiffness of laminated strips, so they lower the buckling loads of the laminated strips, too. In this paper a new method is proposed to predict the buckling loads of the laminated strips with a surface notch. The theoretical and experimental results show that the buckling loads decrease as the depth or width of the surface notches increase; when the stacking sequence of the laminated strips is [0°/0°/+ θ/-θ/0°/0°/+θ/-θ] s , the buckling load decrease as θ increases. It proves that the method is reliable and significant.
文摘The paper presents examples of technological designs for concrete placement in road bridges constructed during the S5/S 10 expressway extension in Poland. The project included eight concrete or composite bridge structures with different numbers of decks. The concrete placement technology is presented for the following bridge decks： slabs cast-in-situ, composite with precast or VFT （prefabricated composite beam） beams and mixed with cast in situ slabs and VFT-WIB （filler beam） beams. Continuous concrete placement was adopted for almost all the bridge superstructures except the mixed-type decks where construction joints were necessary. To control shrinkage, formwork deformations and existing restraints, the concrete was poured in layers and in stages. The design pace of concrete placement was moderate to be regulated at site without compromising safety and quality. The placement methods enabled both efficient and safe concrete pours.
