超深大直径旋喷桩垂直度检测及控制研究

Study on verticality detection and control of ultra-deep large diameter jet grouting pile

旋喷桩施工深度的增加不仅意味着地层条件更加复杂,也给旋喷桩的垂直度控制增加难度。以某锚碇区域深层地基处理项目为例,结合超深大直径旋喷桩施工关键质量控制手段,同时引入自寻北光纤陀螺仪垂直度偏差检测技术,对旋喷桩施工不同阶段的垂直度检测以及控制措施进行了分析。在分析深层超高压旋喷桩垂直度的影响因素的基础上提出了不同施工阶段旋喷桩垂直度的控制措施,旋喷桩垂直度受引孔施工和旋喷施工两个过程影响,具体影响因素包括地层条件、引孔机械及配套设备、引孔钻进工艺以及旋喷钻杆等多个方面,由此提出了一系列的针对性措施。试验结果表明,多种手段的结合能够有效使得深层地基加固旋喷桩施工垂直度达到设计要求以及质量控制指标。

The increase of jet grouting pile’s construction depth not only means more complex ground conditions,but also adds difficulty to verticality control of the pile.It takes an anchor area’s deep foundation treatment project as an example,combines the key quality control measures of ultra-deep and large diameter high pressure jet grouting pile construction,and introduces the self-seeking fiber-optic gyroscope verticality deviation detection technology,to analyze the perpendicularity test and control measures at different stages of the jet grouting pile construction.It puts forward the control measures of perpendicularity of rotary jet piles at different construction stages on the basis of analyzing the influencing factors of perpendicularity of deep ultra high-pressure rotary jet piles.Perpendicularity of jet grouting piles is affected by the two processes,pilot hole construction and rotary jetting construction,and the specific factors include the stratum conditions,the pilot hole machinery and auxiliary equipment,the pilot hole drilling process and the rotary jet drilling rods,etc.,and a series of specific measures are thus proposed.The test results show that the combination of various means can effectively make the perpendicularity of high pressure jet grouting pile for deep foundation reinforcement reach the design requirements and quality control indexes.