【摘要】 开展了水平静力和撞击荷载作用下高桩基础的1g大比例模型试验研究,测试获得了桩顶水平静动力作用力、桩身水平静力变形、桩身水平振动响应、桩身静动力弯矩及桩侧静动力土压力等。发现由实测桩身静力弯矩推算的桩周土反力规律与实测静态桩周土压力规律较为一致;水平撞击荷载作用下,动态桩周土反力与撞击力时程曲线密切相关。结合弹性地基梁线弹性动力模型及静动力p–y曲线模型的分析揭示了桩土静动力相互作用机理及其对桩基内力和变形的影响规律。综合比较了上述分析模型的理论计算结果及试验实测结果,推荐采用复合刚度动力p–y曲线模型分析水平撞击荷载作用下的高桩基础,其分析结果与实测桩身振动响应和内力均吻合良好。最后采用该模型对现场防撞桩进行了防撞分析。更多还原

【Abstract】 A series of model tests at 1g are carried out to study behaviors of elevated piles subjected to both lateral static and impact loading.The horizontal static and impact loading,deflection,horizontal dynamic response,static and dynamic bending moments of the pile shaft as well as the static and dynamic soil pressures on the pile shaft are measured.It is found that the characteristics of static soil reaction to the pile shaft deduced from the bending moment of the pile shaft consistent with those of the measured static soil pressure on the pile shaft.For the pile subjected to the lateral impact loading,the dynamic soil reaction to the pile shaft is heavily related to the time-history of impact loading.Associated with the analysis by Winkler linear models as well as the static and dynamic p–y curve models,the characteristics of pile-soil static and dynamic interaction and its effects on bending moment and deflection of the pile shaft are investigated.The numerical results of the above models are compared with the test results,based on which the complex stiffness dynamic p–y curve model is recommended for the analysis of elevated piles subjected to the lateral impact loading.Its analytic results are in good agreement with the test results of the dynamic responses and bending moment of the pile shaft,and the model is used for the anti-collision analysis of an in-situ elevated pile.更多还原