桥面铺装与小箱梁的共同作用试验

Experiment of Coaction of Bridge Deck Pavement and Small Box Girder

对小箱梁桥进行了单梁和实桥试验,通过对比铺装前后挠度的变化,评价铺装所起的作用。用铺装前的试验求出综合弹性模量,用铺装后的挠度值对应的抗弯惯性矩与假想的铺装参与厚度对应的理论抗弯惯性矩比较,得到铺装层实际参与共同受力的程度。结果表明:接触面进行了凿毛处理,可大幅度提高铺装层参与结构共同受力的程度,铺装层可100%参与小箱梁共同受力;一般情况下约70%铺装层参与小箱梁共同受力,对于8 cm铺装层,设计中可取铺装层厚度的60%或扣除3 cm考虑铺装层参与共同作用;铺装层使小箱梁的横向受力更为均匀。

Load tests on a single small box girder and a bridge were carried out to evaluate the effects of deck pavement by comparing the deflections of the girders before and after the pavement surfaced. The comprehensive elastic modulus was obtained from the test before pavement surfaced, and the coaction degree of the bridge deck pavement and the girders was obtained by comparing the flexural inertia moment corresponding to the deflection in the test after pavement surfaced with the theoretical flexural inertia moment corresponding to the supposed thickness of the pavement in work. The results from these tests show that （ 1 ） the rough interface could greatly improve the coaction degree of bridge deck pavement with girders, which could reach 100%; （2） in general cases, the extent of the coaction of bridge deck pavement with girders could reach 70%, and for a pavement with thickness of 8 cm, the thickness of the pavement in coaction could be taken as 60% or 3 cm in thickness could be substracted from the pavement in design; （3） the pavement could improve the uniformity of the transverse load distribution.