【作者】 宋祖民；

【导师】 王成华；

【作者基本信息】 天津大学 ， 结构工程， 2007， 硕士

【摘要】 缺陷桩的出现在桩基施工中往往是很常见的;桩身常见的缺陷形式一般包括桩身局部断裂、桩身局部扩径、桩身局部缩径等。目前对于缺陷桩的水平工作性状和桩、土工作机理的研究相对较少,在此前提下,本文对于含有缺陷桩的桩基础的水平工作性状和桩基础中桩、土之间相互工作机理进行了分析研究。本文采用三维非线性有限元法研究了含有缺陷桩的桩基础的水平承载性状和桩、土相互作用机理,研究了出现断桩、缩径桩和扩径桩三种缺陷情况下,桩基础的水平承载性状。首先研究了单桩出现缺陷时的水平承载性状,研究单桩是研究群桩的先导,随后研究了群桩中出现缺陷时的水平承载性状。对于单桩而言要研究不同深度出现缺陷时对单桩的水平承载性状的影响,对于群桩而言要研究不同深度和不同水平位置出现缺陷对群桩的水平承载性状的影响。具体的研究方法为:通过对各种缺陷桩基础桩顶的荷载位移曲线与正常桩基础对比得出含有断桩、缩径桩和扩径桩的各自的工作性状,通过对每种缺陷桩基础中桩身挠曲线、土反力、剪力、弯矩随着荷载的变化情况以及相对于正常桩基础中相应各桩的曲线对比与分析,得出每种缺陷桩基础相对于正常桩基础各自的工作机理。研究成果揭示了缺陷桩对桩基础水平工作性状的影响规律,对出现缺陷桩时桩基础水平承载性状的分析评价、检测和施工技术处理有重要的指导意义。更多还原

【Abstract】 It is common that some of pile foundations emerge defective piles in engineering of pile foundations; The usual defect forms of piles include the party rupture of piles, the party hole enlarged of piles and the party necked-in of piles, etc. Nowadays the analyses of horizontal working behaviour and mechanism of the pile foundations with defective piles had not been too much. In this precondition, the horizontal load-bearing behavior and the working mechanism of pile foundations with defective pile has been studied under horizontal loadings.In this book, the method of three-dimesional finite element had been used to analyse the horizontal load-bearing behavior and working mechanism of pile foundations with defective piles under horizontal loadings.The horizontal load-bearing behavior of single pile with defect is researched firstly,research single pile is forerunner of research group piles,then the horizontal load-bearing behavior of group piles with defect is researched.We research the effect of horizontal load-bearing behavior of different depth defect for single pile,research the effect of horizontal load-bearing behavior of different depth and different place defect for group piles. we conclude the working characteristics of each pile foundation with defect under horizontal loadings, and through comparing the curve of P-S of pile foundation with different defect with pile foundation without defect we conclude the working behavour of pile fonundations with rupture piles, enlarged piles or nicked piles. And through comparing the bend curve,soil force,shearing force and moment of pile with different defect with the pile foundation without defect, we conclude the working mechanicsm of pile foundations with different defect relative to the pile foundations without defect.The research reveals the regularity of the effect of the defect contributing to the load-bearing characteristic of pile foundations; it contains important guiding significance to the estimating capacity of load-bearing of the whole pile foundations with defect, detccting defective pile and the engineering technique to deal with defective piles.更多还原