摘要
随着目前城市建筑物容量的增大,对作为其主要承载构件的桩基础的承载性能提出了更高的要求。桩-土相互作用问题是桩基水平承载性能研究中必须考虑的重要内容,该问题的研究对于完善桩基础设计理论和指导工程实践具有重要意义。基于Vesic圆孔扩张理论,分析水平荷载作用下桩侧土体的实际受力状态,根据桩身产生水平位移后桩周土应力为近似椭圆形非均匀分布的特点,综合考虑纵向应力变化、桩基整体转动和桩-土摩擦效应对桩侧土抗力的影响,建立二维平面状态下的桩-土相互作用的力学模型,以此推导水平荷载作用下的桩侧土抗力计算公式,得到基于应力增量的p-y曲线计算方法,并通过实例计算验证该方法的适用性,最后针对桩-土参数进行影响因素分析。对比所提方法的计算结果与模型试验的结果可知:将该理论方法应用于水平荷载作用下桩侧土体力学效应的计算时,计算结果和现场实测数据较吻合,尤其在桩基受荷产生较大水平位移时,两者表现出了较好的一致性。通过对桩-土参数等影响因素的计算分析,讨论了桩径、土体内摩擦角和土体变形模量等桩-土参数对桩周土体应力结果的影响,得到了桩周不同位置处土体径向应力和切向应力的变化规律。
The increase in the capacity of urban buildings has led to higher requirements for the bearing capacity of pile foundations. The pile-soil interaction is an important subject in studies on the horizontal bearing capacities of pile foundations, which are of significance to improve the design theory of pile foundations and guide engineering practices. Based on the Vesic expansion theory, according to the characteristics of the soil stress after the horizontal displacement of the pile body, assumed to have an elliptical nonuniform distribution, the effects of the vertical stress changes, rotation and deflection of the pile foundation, and pile-soil friction on the lateral soil resistance were comprehensively considered. A calculation formula for the soil resistance on the pile side under horizontal loads is derived. A method of p-y curve based on the stress increment is obtained. A mechanical model of the pile-soil interaction in a two-dimensional plane state is established. The applicability of the method is verified by examples. The influences of pile and soil parameters are analyzed in detail. According to the comparison of the results calculated using this method to those obtained by the model test, the theoretical method proposed in this study is used for the calculation of the mechanical response of the soil on the pile side under horizontal loads. The results obtained by this method are in good agreement with the measured data in the model test, particularly when a larger horizontal displacement of the pile foundation is produced. Through the computation and analysis of the pile and soil parameters, the influences of the pile diameter, internal friction angle, and deformation modulus of the soil on the soil stress around the pile are analyzed. In addition, the change rules of the radial and tangential stresses of the soil at different locations around the pile are obtained.
作者
张小玲
赵景玖
杜修力
ZHANG Xiao-ling;ZHAO Jing-jiu;DU Xiu-li(School of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100124,China;Key Laboratory of Urban Security and Disaster Engineering,Ministry of Education,Beijing University of Technology,Beijing 100124,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2021年第6期19-26,共8页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51778020)
国家自然科学基金创新研究群体资金项目(51421005)。
