预应力混凝土桥梁悬臂浇筑的施工控制

对于采用悬臂浇筑施工方法的预应力混凝土桥梁,运用自适应控制理论进行结构参数识别和误差分析;利用BP人工神经网络确定主梁预拱度;在施工过程中对主梁挠度进行连续监测.借助预埋的钢弦式传感器,测试主梁应变,分析了混凝土收缩、徐变、温度等因素对应变测试的影响,并提出修正方法.实桥应用表明,使用自适应控制理论结合BP人工神经网络,可以预测主梁合理预拱度;混凝土收缩、徐变对应力测试的影响不容忽视;实测应变修正方法易于使用,修正值与理论值偏差较小.

Control technique for construction of pre-stressed-concrete cantilever casting bridge

Adaptive control theory, structural parameter identification and error analysis are used to control the construction of pre-stressed-concrete cantilever casting bridge. The construction camber for main beam can be determined by BP artificial neural network. The deflection of main beam should be tested persistently. Strain sensors are previously located in beam to determine the concrete strain. The influencing factors, such as shrinkage, creep, temperature, on strain test is analyzed, and the strain correction method is proposed. Practical application approved that adaptive control theory combining with ANN could forecast appropriate camber. The factor of concrete shrinkage and creep could not be ignored on strain test of main beam. The correction method on measured strain is feasible and accurate. 2 tabs, 4 figs, 9 refs.