The present practice in Bangladesh for erection of girders is placing the girder directly on the bearing pad and joining the adjacent two spans in deck slab level by adopting expansion joints, as the bridges are prese...The present practice in Bangladesh for erection of girders is placing the girder directly on the bearing pad and joining the adjacent two spans in deck slab level by adopting expansion joints, as the bridges are presently designed as simply-supported beam bridge. The main disadvantage of this type of bridges is that, the seismic resistance is weak, and under the external force beyond the design range, the bridges are more likely to fall in danger because of failure in girders. Also they have expansion joints for each span, which affects the comfort of driving and the overall integrity of the bridge deck is poor [1]. Therefore, design and construction of the bridges have been revised to establish continuity between girders of two adjacent spans and transform the bridge as simply supported continuous beam bridge [2]. Temporary bearing (sandbox) method is proposed in this paper to solve the system transformation of continuous beam bridges. Design of the temporary bearing is very simple and can be manufactured at site. This method has been proved in construction of Arial Kha Bridge and can be applied for other similar bridges in Bangladesh.展开更多
A proven beam-track contact model was used to analyze the track-structure interaction of CWR (continuously welded track) on bridge. Considering the impact of adjacent bridges, the tower-cable-track-beam-pier-pile fini...A proven beam-track contact model was used to analyze the track-structure interaction of CWR (continuously welded track) on bridge. Considering the impact of adjacent bridges, the tower-cable-track-beam-pier-pile finite element model of the cable-stayed bridge was established. Taking a bridge group including 40-32m simply-supported beam and (32+80+112)m single-tower cable-stayed bridge and 17-32m simply-supported beam on the Kunming-Shanghai high-speed railway as an example, the characteristics of CWR longitudinal force on the cable-stayed bridge were studied. It is shown that adjacent bridges must be considered in the calculation of the track expansion force and bending force on cable-stayed bridge. When the span amount of adjacent bridges is too numerous, it can be simplified as six spans; the fixed bearing of adjacent simply-supported beams should be placed on the side near the cable-stayed bridge; the track expansion device should be set at the bridge tower to reduce the track force near the bridge abutment.展开更多
Let D<sup>+</sup> be simply connected bounded domain with the boundary ∈C<sub>n<sup>n</sup></sub>;（0【u【1）,D<sup>-</sup>=E\ , D=D<sup>+</sup> ∪D-, we c...Let D<sup>+</sup> be simply connected bounded domain with the boundary ∈C<sub>n<sup>n</sup></sub>;（0【u【1）,D<sup>-</sup>=E\ , D=D<sup>+</sup> ∪D-, we consider the complex equationwhere A（z） is a n-order continuously differentiable function, and <sup>k</sup> A（z）/az’EL,,z（E）,k=0,1, …,n, p】2. The so-called Riemann type boundary problem of complex equation （1） is to find a piecewise regularsolution w （z） in D, whose boundary value <sup>k</sup>w （t）/ <sup>k</sup>（k=0,1,…,n） continuous on and satisfyingthe boundary展开更多
文摘The present practice in Bangladesh for erection of girders is placing the girder directly on the bearing pad and joining the adjacent two spans in deck slab level by adopting expansion joints, as the bridges are presently designed as simply-supported beam bridge. The main disadvantage of this type of bridges is that, the seismic resistance is weak, and under the external force beyond the design range, the bridges are more likely to fall in danger because of failure in girders. Also they have expansion joints for each span, which affects the comfort of driving and the overall integrity of the bridge deck is poor [1]. Therefore, design and construction of the bridges have been revised to establish continuity between girders of two adjacent spans and transform the bridge as simply supported continuous beam bridge [2]. Temporary bearing (sandbox) method is proposed in this paper to solve the system transformation of continuous beam bridges. Design of the temporary bearing is very simple and can be manufactured at site. This method has been proved in construction of Arial Kha Bridge and can be applied for other similar bridges in Bangladesh.
基金Project(51178469) supported by the National Natural Science Foundation of China
文摘A proven beam-track contact model was used to analyze the track-structure interaction of CWR (continuously welded track) on bridge. Considering the impact of adjacent bridges, the tower-cable-track-beam-pier-pile finite element model of the cable-stayed bridge was established. Taking a bridge group including 40-32m simply-supported beam and (32+80+112)m single-tower cable-stayed bridge and 17-32m simply-supported beam on the Kunming-Shanghai high-speed railway as an example, the characteristics of CWR longitudinal force on the cable-stayed bridge were studied. It is shown that adjacent bridges must be considered in the calculation of the track expansion force and bending force on cable-stayed bridge. When the span amount of adjacent bridges is too numerous, it can be simplified as six spans; the fixed bearing of adjacent simply-supported beams should be placed on the side near the cable-stayed bridge; the track expansion device should be set at the bridge tower to reduce the track force near the bridge abutment.
文摘Let D<sup>+</sup> be simply connected bounded domain with the boundary ∈C<sub>n<sup>n</sup></sub>;（0【u【1）,D<sup>-</sup>=E\ , D=D<sup>+</sup> ∪D-, we consider the complex equationwhere A（z） is a n-order continuously differentiable function, and <sup>k</sup> A（z）/az’EL,,z（E）,k=0,1, …,n, p】2. The so-called Riemann type boundary problem of complex equation （1） is to find a piecewise regularsolution w （z） in D, whose boundary value <sup>k</sup>w （t）/ <sup>k</sup>（k=0,1,…,n） continuous on and satisfyingthe boundary
