大型冷却塔桩基缺陷与补强对结构影响的分析

某电厂大型冷却塔桩基由于不当的截桩处理，导致约30％的桩基被截断了25％的桩长。采用整体有限元方法分析了截桩所导致的基础不均匀沉降及其对混凝土塔壳受力状态的影响，以及自重、沉降、风组合作用下的桩基截断区的长短桩效应。结合冷却塔结构的受力特点，提出了对截桩较为集中的区域采用局部补桩方案进行加固处理，并对补桩后的塔壳、基础等受力状态进行了分析，结果表明补桩方案合理可行。

Structure Stress Analysis for Influence of Derects and Reinforcement of Pile Foundation about a Large-scale Cooling Tower

Nearly thirty percent piles were cut off about twenty five percent of pile length during the foundation constraction of a large - scale cooling tower. A finite element model for the whole structure are adopted for the evaluation of the differential settlement and its effects on the stress of the concrete shell. Moreover, the long-short piles issue is analyzed under the combined actions of dead load, differential settlement and wind load. Additional piles are adopted to strengthen the foundation according to the mechanical property of the tower in the north-east zone where most of the piles were cut off. The post-strengthening mechanical behaviors of the concrete tower shell and foundation etc. are analyzed , and the results show that it is reasonable to strengthen the foundation by adding piles.