波纹钢腹板连续刚构桥扭转与畸变的试验研究

Experimental Study on Torsion and Distortion of Continuous Rigid Frame Bridge with Corrugated Steel Webs

设计制作3跨单箱单室变截面波纹钢腹板连续刚构桥和等效的普通混凝土腹板连续刚构桥的模型,通过2个模型桥的扭转与畸变对比试验,从挠度、沿梁高度方向的翘曲应变、箱梁混凝土顶底板的翘曲应力和波纹钢腹板的翘曲剪应力4个方面,分析波纹钢腹板连续刚构桥和普通混凝土腹板连续刚构桥的扭转和畸变特点。结果表明:波纹钢腹板连续刚构桥的抵抗扭转和畸变能力比普通混凝土腹板连续刚构桥弱,但强于波纹钢腹板简支箱梁桥;墩梁固结提高了波纹钢腹板箱梁的整体抗扭能力,且箱梁各截面的抗扭转和畸变能力与该截面距墩顶墩梁结合处的距离有关,距离越近,截面抵抗扭转和畸变的能力越强,反之越弱;计算波纹钢腹板箱梁在偏载作用下的挠度和应力时,要考虑扭转和畸变的影响。

The models of three-span single cell box variable cross-section continuous rigid frame bridge with corrugated steel webs and the equivalent continuous rigid frame bridge with ordinary concrete webs were designed and constructed. By the comparison tests of the torsion and distortion of the two models, from four aspects as the deflection, the warping strain along the height direction of box girder, the warping stress of the top and bottom concrete slabs of box girder as well as the warping shear stress of corrugated steel webs, the characteristics of torsion and distortion of the continuous rigid frame bridge with corrugated steel webs and the continuous rigid frame bridge with ordinary concrete webs were analyzed. The results show that the ability to resist torsion and distortion of the continuous rigid frame bridge with corrugated steel webs is weaker than that of the continuous rigid frame bridge with ordinary concrete webs but better than that of the simply supported box girder bridge with corrugated steel webs. The consolidation of the girder and pier has improved the whole ability to resist torsion of the box girder with corrugated steel webs. The ability of each section of the box girder to resist torsion and distortion is related with the distance of the section from the pier-beam junction, which is better with shorter distance and weaker with longer distance. Attention should be paid to the effects of torsion and distortion when calculating the deflection and stress of the box girder with corrugated steel webs under eccentric load.