寒区某超长隔震结构建造全过程温缩变形分析

Analysis on Thermal Shrinkage Deformation during Whole Construction of an Ultra-long Isolated Structure in Cold Region

针对严寒地区某超长隔震结构建造周期长、平面形状复杂、结构跨度大、季节温差显著及分阶段施工的特点,建立了超长隔震结构建造全过程隔震层温缩变形的计算方法,结合现场的施工进度、方案和步序,采用有限元软件对建造全过程进行了详细的模拟,分析了结构建造全过程隔震层的温缩变形大小及演化规律,并与现场实测结果进行对比验证,最后探讨了结构分阶段施工、施工路径及后浇带设置方式对隔震层温缩变形的影响规律.结果表明:建造全过程温缩变形的模拟结果与实测结果吻合较好,隔震层的温缩变形随着施工进度推移大体呈周期性变化,且与环境温度变化有很大的相关性;超长隔震结构分阶段施工时,各阶段结构之间存在相互约束作用,结构最终的温缩变形是各阶段结构协调变形的结果;合理的施工路径和结构单元划分,能有效减小隔震层的温缩变形;相较于不设置后浇带的情形,当结构后浇带处附加钢筋连通时,隔震层最大温缩变形仅降低了6.3%,而当后浇带处钢筋全部搭接时,隔震层最大温缩变形降低36.3%.

Because of the characteristics of an ultra-long isolated structure in cold regions,such as long construction period,complex plane shape,large structure span,significant seasonal temperature difference,and multi-stage construction,a calculation method for the thermal shrinkage deformation of the isolation layer during the whole construction process of the ultra-long isolated structure is established.Combined with the site construction progress,scheme,and sequence,the construction process is simulated in detail using finite element software,and the size and evolution law of the thermal shrinkage deformation of the isolation layer during the construction process of the structure are analyzed.The simulated results are compared with the field measurement results.Finally,the influence rules of structure construction in stages,construction path,and post-pouring belt setting mode on the thermal shrinkage deformation of the isolation layer are discussed.The analysis results show that the simulation results of the thermal shrinkage deformation during the construction process agree well with the measured results.The thermal shrinkage deformation of the isolation layer generally changes periodically with the progress of construction and has the change in ambient temperature.When the ultravery-long isolation structure is constructed in multi-stage,there is mutual restraint between the structures in each stage,and the final thermal shrinkage deformation of the structure is due to the coordinated deformation of the structure in each stage.Reasonable construction path and structural unit division can effectively reduce the thermal shrinkage deformation of the isolation layer.Compared with the case without the post-pouring belt,the maximum thermal shrinkage deformation of the isolation layer only decreased by 6.3%when the reinforcement was connected at the post-pouring belt,while the maximum thermal shrinkage deformation of the isolation layer decreased by 36.3%when the steel reinforcements were fully overlapped at the post-pouring belt.