桥面铺装对中小跨径PC梁桥校验系数影响分析

Impact of Deck Pavement on the Calibration Coefficient of the Medium and Short Span Pre-stressed Concrete Girder Bridges

为了研究中小跨径预应力混凝土梁桥桥面铺装层对桥梁结构荷载试验校验系数的影响,以114座预应力混凝土连续箱梁及空心板桥作样本,分别计算在不考虑桥面铺装、考虑一半铺装和考虑全部铺装下桥梁结构的横向分布系数的变化,基于不同的保证率给出了3种情况下桥梁结构应变和挠度校验系数的统计规律及统计参数,最后分析了铺装层对桥梁结构校验系数的影响程度,并提出了中小跨径预应力混凝土梁桥考虑铺装不同作用程度的常见校验系数范围.分析结果表明:混凝土铺装厚度对预应力混凝土梁桥横向分布影响很小,而对其结构校验系数的影响程度较大.对于预应力混凝土空心板桥,与不考虑混凝土铺装相比,考虑全部混凝土铺装时的应变校验系数提高约24%,挠度校验系数提高约45%;对于预应力混凝土箱梁桥,与不考虑混凝土铺装相比,考虑全部混凝土铺装时的应变校验系数提高约11%,挠度校验系数提高约21%.其结论可为同类梁桥荷载试验承载能力评定作参考.

In order to study the impact of deck pavement on the calibration coefficient of medium and short span pre-stressed concrete girder bridges in the load test,114 pre-stressed concrete continuous box beam and hollow slab bridges were chosen to be samples,then the transverse distribution＇s of the structure were calculated in the case of considering none,half height and all height of the deck pavement respectively. Based on different reliability,the statistical law and statistical parameters of the strain and deflection＇s calibration coefficient of the bridge structure under three conditions are presented. Finally,the influence of the pavement on bridge structure calibration coefficient was analyzed,and the common calibration coefficient＇s extent was put forward considering different pavement＇s thickness of the medium and small span pre-stressed concrete girder bridges. The results show that the concrete pavement＇s thickness has little impact on transverse distribution of the pre-stressed concrete girder bridge,but has great impact on the structure＇s calibration coefficient. For the pre-stressed concrete hollow slab bridges,compared with those taking no account of concrete pavement,the strain calibration coefficient considering all the height of pavement,increases by about 24%,while the deflection calibration coefficient increases by about 45%; For the pre-stressed concrete box girder bridge,compared with those considering no pavement,the strain calibration coefficient taking all the pavement into consideration increases by about 11%,while the deflection calibration coefficient increases by about 21%. The conclusion can be a reference for evaluating the similar bridges＇ bearing capacity in load test.