盾构下穿大直径挡土桩快速提升清障关键技术研究

RESEARCH ON THE KEY TECHNOLOGY OF RAPID IIFTING OF SHIELD TUNNELING UNDER IARGE DIAMETER RETAINING PILE

依托南宁市轨道交通某区间隧道下穿东西向快速路辅道边坡挡土桩工程,提出了大直径挡土桩快速提升清障的方法,并对其关键施工技术、风险以及控制措施进行了总结。研究结果表明:装配式反力架提升方案在窄施工空间下也具有较好的适应性;挡土桩提升过程中,应注意桩内、桩周同步回灌,回灌压力应小于1 MPa;提出的锚索锚固方案能有效保证大直径挡土桩的提升;提出的风险及相应控制措施能为类似工程提供参考。

This paper relies on the long-distance tunnel of Nanning Rail Transit Line No.3 under the eastwest expressway auxiliary road slope retaining pile project.The method of rapidly lifting the obstacles by largediameter retaining piles is proposed,and the key construction techniques,risks,and control measures of this method are summarized.The research results show that:the assembled reaction frame lifting scheme also has better adaptability under narrow construction space;attention should be paid to the simultaneous recirculation of piles and piles during the lifting process of retaining piles,and the recharge pressure should be less than 1 MPa;the anchor cable anchoring scheme can effectively ensure the lifting of large-diameter retaining piles;the proposed risks and corresponding control measures can provide reference for similar projects.