正断层错动诱发单桩破坏及避让距离研究

发布时间：2018-01-21 03:37

本文关键词： 离心机模拟单桩正断层避让距离　出处：《岩土工程学报》2017年04期 　论文类型：期刊论文

【摘要】：历次地震实例表明基岩断层错动诱发建筑桩基破坏,针对桩基础的近断层破坏机理认识不足。采用土工离心机试验,研究正断层错动引起上覆砂土中单桩基础的破坏。试验详细量测单桩及土体变形,监测桩身轴力及弯矩随基岩错动量的变化规律。试验数据表明,当错动量为0.4 m时,单桩与桩周土体协同变形,桩顶出现显著位移。随着错动量增加,上覆土体变形集中于破裂带,使得桩顶位移显著减少。该破裂带在基岩和土体的交界面上偏离基岩错动方向,与水平面呈80°方向发展至地表,并在单桩靠近断层上盘一侧地表出露。上覆砂土变形可分为静止区、剪切区和刚体位移区。当单桩位于剪切区附近,桩身受弯变形使得桩顶向上盘一侧倾斜。针对正断层错动,单桩在下盘一侧和上盘一侧离开基岩断层线的安全避让距离分别为15 m和10 m。
[Abstract]:The earthquake examples show that bedrock fault pile induced destruction of buildings, in view of the near fault pile foundation. The failure mechanism of the lack of understanding of geotechnical centrifuge test, study fault caused by single pile foundation overlying sand damage. Test with measuring deformation of single pile and soil, variation of axial force of pile and monitoring moment with the fault displacement. The experimental data show that when the displacement is 0.4 m, single pile and soil pile deformation coordination, significant displacement. With the wrong momentum increased, the overlying soil deformation concentrated in the rupture zone, the displacement of pile top decreased significantly. The rupture zone in rock and soil to the interface from Bedrock Dislocation direction, 80 DEG with horizontal direction to the surface and near the side wall in single pile surface faults exposed. The overlying sand deformation can be divided into static zone, shear zone and rigid displacement when single pile in shear area. In the vicinity of the cutting area, the pile is bent and deformed, so that the top of the pile is tilted towards the upper side. For the normal fault dislocation, the safety and avoidance distance of the single pile leaving the bedrock fault line on the footwall side and the upper side is 15 m and 10 m. respectively.

【作者单位】：华侨大学土木工程学院;香港科技大学土木与环境工程系;
【基金】：福建省自然科学基金计划项目(2014J01194,2015J01209) 华侨大学中青年教师科研提升计划项目(ZQN-PY216)
【分类号】：TU473.1
【正文快照】： 历次地震实例表明基岩断层错动引起上覆土体发生永久变形,进而导致地表及地下建筑物严重破坏[1]。此类破坏往往沿着发震断层呈狭窄的带状分布。在查明活断层准确位置的基础上,确定地表“避让带”是有效减轻地震灾害的重要手段[2]。针对不同上覆土体类别,国内外研究人员采用土

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