能量桩桩-土接触面力学特性室内试验研究

基于地源热泵桩埋管形式的能量桩技术逐渐在工程中得到推广应用;但是,针对冷热交换影响下能量桩的承载力特性研究相对较少,尤其针对能量桩-土接触面的摩擦力学特性研究相对更少。基于室内土工试验和南京地区3种具有代表性的典型土样,针对能量桩-黏土、能量桩-粉土和能量桩-砂土接触面的摩擦力学特性进行室内土工直剪试验;着重分析不同桩体温度和桩周土体含水率等情况下能量桩-土接触面力学特性。研究结果表明,相同含水率情况下,能量桩-黏土接触面的温度效应最明显、能量桩-粉土接触面的温度效应次之、能量桩-砂土接触面的温度效应最小;相同桩体温度情况下,桩周土体含水率的大小对能量桩-黏土接触面力学特性的影响最明显、对能量桩-砂土接触面力学特性的影响最小;相关研究成果为能量桩承载力的设计与计算提供一定的参考依据。

Laboratory Experimental on Interface Mechanical Properties of Energy Pile-soil

Energy pile, which is based on ground source heat pump technology, is gradually applied on engineering. However, there is relative little studies focused on the bearing behaviors of energy pile influence by energy exchange, especially little researches focused on the energy pile-soil interface friction. Based on laboratory experiments and three typical Nanjing soil samples, the energy pile -soil interface friction behaviors influenced by temperature and water content were focused and analyzed. The test results show that temperature effect of energy pile-clay interface friction is larger than that of energy pile-silt and energy pile-sand interface friction with the same water content. The behaviors of energy pile-clay interface friction influenced by water content is larger than those of energy pile-silt and energy pile-sand interface friction. The research results can be provided a frame of reference to the design and calculation of the bearing capacity of energy piles.