现浇混凝土薄壁管桩复合地基动力反应特性分析

Dynamical analysis of the cast-in-situ concrete thin-wall pipe pile composite foundation

针对目前现浇混凝土薄壁管桩复合地基动力特性分析中二维计算模型的不足,提出了一种基于等效刚度原理的简化模型。基于河海大学岩土工程研究所开发的二维动力有限元计算程序,并通过工程实例,分析了这种新型复合地基的动力特性。研究结果表明,现浇混凝土薄壁管桩复合地基在地震作用下,与原天然地基相比,地表水平向绝对加速度增大,竖直向绝对加速度显著减小;地基内部水平向受力的整体性较好,而竖直向较差。从地基的动剪应力计算结果可知,现浇混凝土薄壁管桩复合地基对抗震有利。

The method of dealing with 2D calculation model of the cast-in-situ concrete thin-wall pipe pile composite foundation in dynamic characteristic analysis has been simplified and presented due to its shortcomings in current methods. It is systematically studied through the calculation program exploited by Geotechnical Research Institute of Hohai University that dynamic characteristics of this composite foundation is preferable to original foundation. The examples show that the horizontal acceleration of ground surface increscent but the vertical horizontal acceleration decreases,the holistic stress surface consistent except for the verticality,and the earthquake resistance of this new type composite foundation predominant from the result of dynamic shear stress calculation.