回填土液压夯实对柱下独立基础结构受力影响规律研究

Study on the influence of hydraulic compaction of backfill on the stress of independent foundation structure under column

为研究独立基础回填夯实过程对柱子及框架结构产生的影响,通过现场监测对柱下独立基础拉梁与框架柱的受力变化进行监测及内力计算,并结合数值模拟对现场监测数据进行对比分析。监测结果表明:柱下独立基础施工过程中,钢筋与混凝土之间变形受力基本协调。柱基本受压,拉梁两端受力较为明显,表现为典型的结构承受上部荷载。钢筋应力与混凝土应变变化总体呈增大-波动-稳定的规律,波动出现在第一步回填夯实阶段,随后发生应力重分布恢复稳定状态。柱间土夯实后,回填液压夯实对下部已经形成的框架结构稳定性影响不大。通过数值模拟可以看出,结构受力危险点与现场测点位置基本一致,远离柱与梁进行冲击作用时受到的影响最小,说明只有在结构上面进行回填夯实时,对结构影响最大,而在结构其他区域进行夯实时,影响较小。

In order to study the influence of independent foundation backfilling and tamping process on columns and frame structures,the stress changes of independent foundation tie beams and frame columns under columns are monitored and the internal forces are calculated through on-site monitoring,and the on-site monitoring data are compared and analyzed in combination with numerical simulation.The monitoring results show that the deformation and stress between reinforcement and concrete are basically coordinated during the construction of independent foundation under the column.The column is basically compressed,and the stress at both ends of the tie beam is obvious,which shows that the typical structure bears the upper load.The change of reinforcement stress and concrete strain is generally in the rule of increase,fluctuation and stability.The fluctuation occurs in the first backfilling and compaction stage,and then the stress redistributes to restore the stable state.After the soil between columns is compacted,the hydraulic compaction of backfill has little effect on the stability of the frame structure formed below.It can be seen from the numerical simulation that the position of the structural stress dangerous point is basically the same as that of the on-site measuring point,and the impact effect on the structure far away from the column and beam is minimal,which means that only the backfilling and tamping on the structure have the greatest impact on the structure,while the impact on other areas of the structure is small.