洞庭湖大桥组合式沉井施工关键技术及仿真分析

洞庭湖大桥N003#墩组合式沉井直径31.6 m,高17.7 m,埋深16.1 m,下部为钢筋混凝土结构,上部为钢板桩。以该组合式沉井施工为研究对象,总结了大型组合式沉井施工的要点,并对施工安全进行验算。建立仿真分析模型对施工过程中沉井的应力状态、稳定性进行分析。计算结果表明沉井下沉系数、下沉稳定系数满足下沉要求。钢板桩最大有效应力116.5 MPa,最大剪应力66.6 MPa,最大变形7.9 mm,混凝土沉井最大有效应力7.3 MPa,均满足结构受力及变形要求。

Key Construction Technology and Simulation Analysis of Combined Caisson for Dongting Lake Bridge

The diameter of the composite caisson of N003#pier of Dongting Lake bridge is 31.6 m,the height is 17.7 m,and the buried depth is 16.1 m.The lower part is reinforced concrete structure,and the upper part is steel sheet pile.Taking the construction of the combined caisson as the research object,the key points of the construction of the large-scale combined caisson were summarized,and the construction safety was checked.The simulation analysis model was established to analyze the stress state and stability of caisson during construction.The calculation results show that the sinking coefficient and sinking stability coefficient meet the sinking requirements.The maximum effective stress of steel sheet pile is 116.5 MPa,the maximum shear stress is 66.6 MPa,the maximum deformation is 7.9 mm,and the maximum effective stress of concrete caisson is 7.3 MPa,all of which meet the requirements of structural stress and deformation.