研究目的:采用数值计算的方法,考虑土芯的承载作用,对闭合型地下连续墙基础的沉降特性、内外侧摩阻力、端阻力、土芯顶部反力及其荷载分担比特性进行分析和研究,并探讨基础的荷载传递特性.研究结论:闭合型地下连续墙基础呈整体沉降形式;墙内土芯中上部土体其沉降与墙身基本同步;土芯底部附近的土体以压缩变形为主;基础的竖向承载力由其沉降控制,且具有“端承摩擦墙”的承载特性;墙身内、外侧摩阻力的发挥过程和机制不同,墙身外侧土体以剪切变形为主,其外侧摩阻力由上向下发挥;而内侧摩阻力,只有当土芯底部受到足够大的反力时,土芯才会产生相对于墙壁向上的压缩变形而使其内侧摩阻力由下而上逐渐发挥出来.墙身内侧摩阻力、外侧摩阻力和端阻力存在异步发挥现象,外侧摩阻力先于端阻力发挥,而内侧摩阻力最后发挥,且内侧摩阻力沿深度具幂函数分布形式.%Research purposes: With the numerical computation, considering the bearing capacity of the soil core within the closed underground diaphragm wall, the characters of the load - settlement, inside and outside frictional resistances, end - bearing resistance, resistance on the top soil core and its load - sharing ratio of the closed diaphragm wall were analyzed in detail, and the load transfer characteristics of the closed diaphragm wall were discussed. Research conclusions: The closed underground diaphragm wall was in form of the whole settlement, and the up and middle parts of soil core presented the basic synchro settlement with the wall. The bottom part of soil core behaved the compressive deformation feature. The vertical load - bearing of the base relied on its settlement with the bearing characteristic of end skin friction bearing wall. As the inside and outside skin frictions of the wall presented the dissimilar operation mechanism, the most deformation of the the soil outside of the wall were the shearing deformation featured with effects of the outside skin friction from top to bottom. However, the inside skin friction, due to suffering upward compressive deformation, took place gradually from the bottom to the top when the bottom part of soil core was subjected to the reaction. The effect of the outside skin friction preexisted the end - resistance, sequentially the inside skin friction. The inside resistance along the depth presented exponential function expression.
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