单箱三室波形钢腹板PC连续箱梁桥监测技术

Monitoring Technology of PC Continuous Box-girder Bridge with One-box and Three-room Corrugated Steel Webs

为了解多室箱波形钢腹板箱梁的力学性能,在施工及运营阶段对某单箱三室波形钢腹板PC连续箱梁桥控制截面的应变及标高进行监测。结果表明,预应力钢筋张拉后控制截面应力及标高与拆架后吻合。计算波形钢腹板PC连续箱梁桥活载效应时,应选用合理的内力增大系数值来计入偏心荷载对截面内力的影响。波形钢腹板PC连续箱梁桥中的温度应力超过了活载应力,成为设计控制因素。去除温度梯度、沉降、混凝土收缩徐变、预应力损失等因素影响产生的应力,运营阶段应力与竣工时应力相当。

In order to investigate the mechanical properties of girders with multiple-room corrugated steel webs, the stress and elevations in the control sections of a PC continuous box-girder bridge with corrugated steel webs were monitored during the construction and service phases. The results show that, the stress and elevations in the control sections after the pre-stressing of the reinforcements are the same with those after the scaffold removing. Reasonable amplification factors should be introduced to account for the effect of loading eccentricity in the calculation of the live load effect. Thermal stresses in PC continuous box-girder bridge with corrugated steel webs are more significant compared to live load stresses and become the control load in design. When excluding the stresses caused by temperature gradient, settlement, concrete shrinkage and creep, the stress during service is very close to that after construction.