受限空间桩基施工影响因素敏感性分析

Analysis on Sensitivity of Influencing Factors in Pile Foundation Construction in Confined Spaces

摘要:

城市多层高架立体改扩建工程中，新建桩基常处于既有桥梁下方或紧邻既有结构，施工空间严重受限，施工效率与质量控制难度显著增大。为此，从空间几何约束、设备适配性、施工工艺、地质条件、组织管理5个维度，系统识别受限空间桩基施工的关键影响因素；依托上海外环西段工程，采用单因素敏感性分析法，以单桩施工周期为评价指标，计算各因素敏感度系数β，定量判别各因素对施工效率的影响程度；并针对钻孔、钢筋笼下放、混凝土浇筑等关键工序提出分级控制措施，为同类受限空间桩基施工效率提升与质量保障提供参考。

Abstract:

In the three-dimensional reconstruction and expansion of urban multi-story elevated structures, the new pile foundations are often located under existing bridges or adjacent to existing structures, resulting in severely restricted construction space and significant challenges to construction efficiency and quality control. Therefore, the key influencing factors of pile foundation construction in confined spaces are systematically identified from five dimensions of spatial geometric constraints, equipment adaptability, construction technology, geological conditions and organizational management. Relying on the Shanghai Outer Ring West Section Project, the single-factor sensitivity analysis method is adopted with the single pile construction period as the evaluation index to calculate the sensitivity coefficient β of each factor and quantitatively determine the impact of each factor on construction efficiency. And aiming at the key processes of drilling, lowering of steel cages, and pouring concrete, the grading control measures are proposed, providing a reference for improving construction efficiency and ensuring quality in similar confined-space pile foundation projects.