论文部分内容阅读
为完善圆形地连墙设计理论,探讨了现行规范方法的力学概念、环向应力计算方法、土-结构相互作用及环向刚度折减系数等关键问题,基于薄壳理论推导了地基双向弹簧条件下圆形地连墙的基本微分方程,改进非线性土体弹簧模型以考虑土压力发挥极限值所需的位移,引入连续弹簧模拟环形内衬,采用增量法计入施工过程影响,并编制了有限元程序;同时,提出采用单元体试验研究圆形地连墙环向刚度折减系数取值方法,考虑接缝刚度与宽度、地连墙半径、槽段平均长度等因素建立了折减系数计算公式,最后,以阳逻大桥圆形锚碇基坑工程为例进行了计算与对比分析。结果表明:典型条件下折减系数为0.467~0.679;该方法位移计算值与实测值基本吻合,克服了现行方法无法分析支护结构环向应力及地连墙两侧土压力发展过程的缺陷;计算参数物理意义明确、易于获取,可为工程设计提供较为全面的参考依据。
In order to improve the design theory of circular ground wall, the key concepts of the mechanics concept, the method of hoop stress calculation, the soil-structure interaction and the reduction coefficient of circumferential stiffness are discussed. Based on the thin shell theory, Under the condition of circularly partitioning the wall of the basic differential equation, improved nonlinear soil spring model to consider the pressure required to exert the limit of the earth pressure displacement, the introduction of continuous spring simulation of the annular lining, incremental method into account the impact of the construction process, and At the same time, the method of unit body test is used to study the method of determining the value of the stiffness reduction coefficient of circumferential wall connected by circular walls. The stiffness and width of the joint, the radius of the continuous wall and the average length of the groove wall are established. Then, the calculation and contrast analysis of the circular anchorage foundation pit project of Yangluo Bridge are taken as an example. The results show that the reduction coefficient is 0.467 ~ 0.679 under typical conditions. The calculated displacements of the method are in good agreement with the measured values, which overcomes the defects that the current method can not analyze the hoop stress of retaining structure and the earth pressure on both sides of the wall. The physical meaning of calculation parameters is clear and easy to obtain, which can provide a more comprehensive reference for engineering design.