微挠度桥梁及其试验研究

由于混凝土收缩、徐变和活载的作用,利用常规的方法很难满足机车对桥梁结构变形的要求,作者提出了一种新颖的结构体系———微挠度桥梁来实现这种要求。常规预应力体系用来消除恒载效应,新型的预应力体系用来消除活载效应及结构时变性效应,此种结构具有自适应性。其机理是通过感知元件监控结构的状态,诊断系统判断结构所处的状态,控制系统控制作动系统通过调整体外束的力调整结构的状态。为了验证微挠度桥梁实现的可能性,作者设计微挠度简支梁模型并实现了上述的控制思路。

Micro-deflection bridges based on the smart prestressing system and an experimental study

The deflection of bridge structure has to be micro so as to meet the requirement of high-speed track transportation.This paper presents a kind of novel micro-deflection bridge structure to fit such deflection demand.The routine prestressing system is used to balance the action of dead load and the smart prestressing system is used to control and modulate the effect of variable and time-dependent action.The smart prestressing system is a self-adapted structure,and its mechanism is as follows:sensor elements monitor the action's effect,the diagnostic package diagnoses the condition of the structure,and the control system dominates the actuator and the actuator modulates the force of external cables.To illustrate the idea of such a smart prestressing system,a model with the self-adapted function is designed and tested,in which the simply supported girder bridge is applied.