| 摘要: |
| 为评价黏土中钻井船插、拔桩对邻近桩基础的影响，开展了自由桩头条件下的1g模型试验，得出插、拔桩过程中所测量物理量数据变化规律，为后续离心模型试验提供了数据基础和试验方法。试验得到各物理量变化规律如下：插桩条件下，随着插桩深度的增加，邻近桩桩身最大弯矩产生的位置及最大土体水平位移产生的位置逐渐加深；拔桩条件下，最大桩身弯矩及最大土体位移值逐渐减小，但拔桩完成后桩身位移和土体位移都未恢复到初始桩状态；插桩初始阶段插桩阻力迅速增加，之后逐渐趋于稳定，拔桩初始阶段拔桩阻力迅速增加，随后进入相对稳定阶段，在桩靴距离土体表面约120 mm时，阻力突降为0。试验分析结果表明，土体位移变化直接导致桩身响应变化，两者存在一定正相关性。 |
| 关键词: 1g模型试验 自由桩头 桩靴 邻近桩 插桩 拔桩 |
| DOI： |
| 分类号:TU473 |
| 基金项目:国家自然科学基金资助项目(51579174) |
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| Scale model tests on effects of spudcan penetration and extraction on adjacent piles |
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TIAN Zhaofeng1,2, WANG Jianhua1,2, FAN Yifei1,2
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1.State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin;2.Geotechnical Engineering Institute, Tianjin University, Tianjin
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| Abstract: |
| In order to evaluate the spudcan penetration and extraction effects on the adjacent piles, the free pile head model tests are carried out in clay under 1g conditions. The change laws of various physical quantities in the process are given by the model tests, and test data and testing methods for the subsequent centrifugal model tests are obtained. The model testing results show that when the spudcan penetrates deeper, the position where the maximum pile moment and the maximum soil displacement appear along the pile becomes deeper. As the spudcan elevates, the maximum pile moment and the maximum soil displacement decrease. However, after finishing of the model tests, the moment along the pile and the soil displacement do not return to their initial state. In the initial stage of the spudcan penetration, the resistance of the spudcan penetration increases rapidly and then gradually stabilizes. And the resistance of the spudcan extraction increases rapidly and then remains relatively stable during the initial stage of the spudcan extraction. When the spudcan shoe is about 120 mm away from the soil surface, the resistance suddenly drops to zero. The testing analysis results show that the displacement change of the soil mass directly leads to the change of the pile body response, and there is a positive correlation between them. |
| Key words: 1g model test free head pile spudcan adjacent pile spudcan penetration spudcan extraction |
