高压喷射注浆桥梁纠偏影响因素显著性分析

Significance Analysis of Influencing Factors for Bridge Rectification by High Pressure Jet Grouting

采用高压喷射注浆联合应力释放的方法,对已偏移桥梁墩台进行纠偏是一项切实可行的技术措施。为提高桥梁纠偏效率,快速恢复高速铁路正常安全运营,在分析高压喷射注浆桥梁纠偏原理基础上,建立了桥梁纠偏理论模型;基于弹性地基梁理论,推导了桥墩顶部位移计算解析式,分析了影响桥梁纠偏效率的主要因素;通过正交试验设计方法,探讨了桥梁纠偏影响因素的显著性,并以现场典型工程案例进行了验证。结果表明:影响桥梁纠偏效率的主要因素为土体地基系数、超孔隙水压力和注浆施工深度。施作应力释放系统后土体地基系数减小,桥墩日纠偏量由0.42 mm快速增至1.04 mm,增幅为148.8%;注浆压力由20 MPa增至25 MPa,产生的超孔隙水压力增大,桥墩日纠偏量由0.39 mm增至0.86 mm,增幅为118.2%;注浆施工深度由19 m增至24 m,桥墩日纠偏量由0.24 mm增至0.40 mm,增幅为69.5%。土体地基系数对桥梁纠偏效率的影响最显著,其次为高压喷射注浆产生的超孔隙水压力,注浆施工深度的影响最小。研究成果可为提高桥梁纠偏效率提供理论依据。

The method of high pressure jet grouting combined with stress release is a feasible technical measure to rectify the offset bridge pier.In order to further improve the efficiency of bridge rectification and quickly resume the normal and safe operation of high speed railway,based on the analysis of the principle of high pressure jet grouting bridge rectification,a theoretical model of bridge rectification was established.Based on the theory of elastic foundation beam,the analytical formula for calculating the displacement at the top of bridge pier was derived,and the main factors affecting the efficiency of bridge rectification were analyzed.Through the orthogonal test design method,the significance of the influencing factors of bridge rectification was discussed,and it is verified by a typical engineering case on site.The results show that the main factors affecting the efficiency of bridge rectification are soil foundation coefficient,excess pore water pressure and grouting construction depth.When the soil foundation coefficient applied by the stress release system is reduced,the daily rectification amount of the pier increases rapidly from 0.42 mm to 1.04 mm,with an increase of 148.8%.When the excess pore water pressure generated by the grouting pressure increases from 20 MPa to 25 MPa,the daily rectification amount of the pier increases from 0.39 mm to 0.86 mm,with an increase of 118.2%.When the grouting construction depth increases from 19 m to 24 m,the daily rectification amount of the pier increases from 0.24 mm to 0.40 mm,with an increase of 69.5%.The soil foundation coefficient has the most significant effect on the bridge rectification efficiency,followed by the excess pore water pressure generated by high pressure jet grouting,and the grouting construction depth has the least effect.The research results provide a theoretical basis for improving the efficiency of bridge rectification.