双排桩支护在既有水厂改造工程中的应用研究

Research on Application of Double-row Pile Support in Reconstruction Project of Existing Waterworks

摘要:

既有水厂改造工程中，基坑开挖需注意对现有建构筑物和管道的保护。某工程中基坑面积较大且深度较浅，适合无支撑式围护结构，因此结合现场情况采用双排桩进行支护。利用MIDAS GTS有限元软件，建立有限元模型分析了基坑开挖过程中双排桩支护对邻近构筑物及管道的保护作用。研究分析发现：随桩径的增大及桩间距的减小，双排桩的侧向刚度增大，对于周边环境的保护作用增强；在软土地区，采用前强后弱的方式可以更有效提升支护效果；综合计算结果及监测数据，优化后的支护方案均满足基坑对周边环境变形的控制要求。

Abstract:

In the reconstruction project of the existing waterworks, when excavating the foundation pit, the attention should be paid to the protection of the existing buildings, structures and pipelines. In a project, the foundation pit is large in area and shallow in depth, making it suitable for the unsupported retaining structures. Therefore, the double-row piles are adopted for support in combination with the on-site conditions. By using the MIDAS GTS finite element software, a finite element model is established to analyze the protective effect of double-row pile support on adjacent structures and pipelines during the excavation process of foundation pit. The research and analysis reveal that with the increase of pile diameter and the decrease of pile spacing, the lateral stiffness of double-row piles increases, and the protective effect on the surrounding environment is enhanced. In soft soil areas, adopting a method of strong support at the front and weak support at the back can more effectively enhance the support effect. Based on the comprehensive calculation results and monitoring data, the optimized support schemes all meet the control requirements of the foundation pit for the deformation of the surrounding environment.