曲线钢箱梁桥吊装施工稳定性分析及控制

Stability analysis and control of hoisting construction for curved steel box girder bridge

曲线钢箱梁桥是在匝道桥中应用较为广泛的结构形式,此结构形式提高了工程项目在建设使用中的安全可靠性,但在吊装过程中,有多种因素会影响到桥梁结构的横向抗倾覆稳定性,各影响因素的影响规律、控制指标和标准尚未很好地解决。针对曲线钢箱梁桥吊装过程的稳定性,借鉴钢桥设计规范中抗倾覆稳定性计算分析方法,研究吊装过程的稳定性,提出吊装稳定系数,计算分析稳定系数与吊点位置、曲率半径、梁段长度、倾斜角度以及风荷载的相关性。结果表明:不同吊装方法对横向抗倾覆稳定性影响不同,横风对稳定系数影响较大,通过对比3种施工方案可知,纵桥向吊点间距建议取为梁段总长的2/3左右。在吊装过程中,尽量保持各吊点钢丝绳工作的同步性,避免节段发生倾斜;在超过六级风时,建议停止施工。

Curved steel box girder bridge is widely used in ramp bridge,which improves the safety and reliability of engineering projects in construction and operation.However,there are many factors that will affect the lateral anti-overturning stability of the bridge structure in the process of hoisting.The influence law,control index and standard of each influencing factor have not been well solved.Aiming at the stability of curved steel box girder bridge in hoisting process,by referring to the calculation and analysis method of anti-overturning stability in steel bridge design code,the stability of hoisting process was studied,and the hoisting stability coefficient was proposed.The correlation between the stability coefficient and the position of hoisting point,curvature radius,length of beam section and wind load was calculated and analyzed.Results showed that the lateral anti-overturning stability was different using different hoisting construction methods,and the transverse wind had a great influence on the stability coefficient.By comparing the three construction schemes,it was suggested that the longitudinal span of the hoisting point should be about 2/3 of the total length of beam section.In the process of hoisting,the synchronization of wire rope worked at each hoisting point should be ensured to avoid beam section tilt.When the wind exceeded six degree,it was recommended to stop construction.