山地建筑能量桩荷载传递机理与承载力计算方法研究

The national "13th five-year plan" pointed to strengthen energy conservation in key areas such as building energy efficiency. Energy pile is an innovative technology that supports the upper building load and simultaneously obtain geothermal energy to realize energy saving and emission reduction. In recent years, the research and application of energy piles have increased rapidly. However, the studies considering the slope topography are still limited. This project aims to study the load transfer mechanism and bearing capacity calculation method of energy piles as building foundations in mountain area based on laboratory test, mode test, numerical simulation and theoretical study. On account of the characteristic of soil in the mountain area, the strength characteristics of energy pile–soil interface is investigated. Numerical simulation models for interaction of energy pile–soil and energy transmission considering asymmetric slope topography are established. Based on the model test regarding slope topography, the load transfer mechanism of building foundation in mountain area in consideration of thermo-mechanical coupling is revealed. Furthermore, the load transfer theoretical model of energy pile regarding slope topography is built. The calculation methods of bearing capacity and displacement for the energy pile is proposed under asymmetric stress and temperature fields condition. The achievements are expected to provide a scientific basis for application of the energy pile on the slope in mountain area.

国家“十三五”规划建议指出加强重点领域节能，强化建筑节能。能量桩在承担上部建筑荷载的同时可以获取地热能，有效实现节能减排。近年来能量桩的研究与应用呈快速增长趋势，但针对山区坡地地形条件下的研究仍少有报道。本项目通过室内试验、模型试验、数值模拟和理论研究等手段，拟针对山地建筑能量桩荷载传递机理与承载力计算方法开展研究。结合山区土体特性，开展能量桩-土接触面强度特性试验研究，建立非对称山区坡地能量桩-土相互作用模型和能量传输数值模型；开展斜坡能量桩模型槽试验，揭示力-热耦合作用下桩基荷载传递机理；建立山区坡地建筑能量桩荷载传递理论计算模型，提出考虑非对称应力场和温度场的桩体承载力和桩体位移计算方法；研究成果将为能量桩在山区坡地条件下的推广应用提供科学依据。

能量桩在承担上部建筑荷载的同时可以获取地热能，有效实现节能减排。近年来能量桩的研究与应用呈快速增长趋势，但针对山区坡地地形条件下的研究仍少有报道。本项目通过室内试验、模型试验、数值模拟和理论研究等手段，针对山地建筑能量桩荷载传递机理与承载力计算方法开展研究。结合山区土体特性，开展能量桩-土接触面强度特性试验研究，建立非对称山区坡地能量桩-土相互作用模型和能量传输数值模型；开展斜坡能量桩模型槽试验，揭示力-热耦合作用下桩基荷载传递机理；建立山区坡地建筑能量桩荷载传递理论计算模型，提出考虑非对称应力场和温度场的桩体承载力和桩体位移计算方法。结果表明低法向应力下温度循环对桩-土接触面力学特性影响较大，而高法向应力下温度循环对桩-土接触面力学特性影响不显著；坡体中非对称土体的分布对能量桩运行过程中的桩-土温度分布有较大影响；水平工作荷载作用下，加热和制冷会引起桩身弯矩的变化，制冷工况对坡地中能量桩的位移变化影响更为显著，多次循环后的桩顶位移不断累积，总体呈增大趋势；提出的荷载传递理论计算模型较为合理。研究成果将为能量桩在山区坡地条件下的推广应用提供科学依据。