温州铁路S1线复合式后注浆灌注桩试桩技术研究

STUDY ON COMPOSITE POST GROUTING PILE TEST TECHNOLOGY OF WENZHOU RAILWAY LINE S1

复合式后注浆将注浆的劈裂、渗透和压密3种作用形式集中在桩底共同发挥作用,并通过桩底环形钢板胶囊的约束,实现了注浆的“三定”原则,能够对浆液进行有效控制和约束,克服了钻孔灌注桩的固有缺陷,从而实现桩基承载力高、施工便捷、质量可控的目标。基于温州S1线上盖开发工程进行复合式后注浆试桩技术研究,通过试桩选型分析、试桩设计及试桩堆载试验,形成复合式后压浆超长灌注设计计算方法以及深厚淤泥质地层中超长钻孔灌注桩桩端复合式后压浆施工控制标准。试验结果表明,全部试桩均体现出良好的完整性及承载性能。

Composite post grouting concentrates the three action forms of splitting,infiltration and compaction of grouting on the pile bottom to play a role together.Through the restriction of annular steel plate capsule at the pile bottom,the"three fixed"principle of grouting is realized,which can effectively control and restrict the slurry and overcome the inherent defects of bored cast-in-place pile,so as to achieve the goal of high bearing capacity of pile foundation,convenient construction and controllable quality.Based on the research on composite post grouting test pile technology of Wenzhou S1 line cover development project,through the analysis of test pile type selection,test pile design and test pile surcharge test,the design and calculation method of composite post grouting super long grouting and the construction control standard of composite post grouting at the pile end of super long bored grouting pile in deep muddy stratum are formed.The test results show that all test piles show good integrity and bearing performance.