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为了解决水平旋喷桩施工引起的地表隆起变形问题,通过对施工过程的简化分析,基于半无限土体平面内圆孔受均布力作用的Verruijt解答,建立了一种新的水平旋喷桩施工引起地表隆起变形的分析方法。基于量纲分析原理,以施工单位长度水平旋喷桩为研究对象,综合考虑高压泵注入土层的能量和土的弹性模量,提出了水平旋喷施工引起周围土体塑性区半径的简化计算方法;利用所提出的地表隆起变形分析方法,探讨了水平旋喷施工过程中常用的旋喷参数(注浆压力、注浆流量和钻喷杆回拔速度)对地表隆起变形的影响规律;将提出的地表隆起变形分析方法应用于工程实例,对比分析了实测数据与计算值。结果表明:注浆压力越大,注浆流量越大,钻喷杆回拔速度越小,引起的地表隆起变形越大,地表变形的最大值均位于水平旋喷桩桩心的正上方;对于施工参数的常用范围,注浆压力每增加10 MPa,地表变形最大值平均增加25.4%;注浆流量每提升50L·min-1,地表变形最大值平均增加33.9%;钻喷杆回拔速度每提升5cm·min-1,地表变形最大值平均减小20.7%;地表隆起变形与桩心水平距离的归一化关系表明,以成桩直径大小的1%作为施工影响范围的控制值,则水平旋喷桩施工的影响范围约为12倍的成桩直径;工程实例表明该方法具有较强的合理性。
In order to solve the problem of the surface bump deformation caused by the construction of horizontal jet grouting pile, a new horizontal jet grouting pile is established based on the simplified analysis of the construction process. Based on Verruijt’s solution of the uniform distribution of circular holes in the semi-infinite soil body, Analysis of surface deformation caused by construction. Based on the principle of dimensional analysis, a rotating jet grouting pile with horizontal length of construction unit is taken as research object. Based on the energy of soil injected into high-pressure pump and the elastic modulus of soil, a simplified calculation of horizontal plastic zone radius Methods; By using the proposed method of surface uplift deformation analysis, the influence regularity of swirl parameters (grouting pressure, grouting flow rate and drilling boom pull-back speed) on surface bump deformation commonly used in horizontal swirl spraying was discussed. The proposed method of surface bump deformation analysis is applied to engineering examples, and the measured data and calculated values are compared. The results show that the bigger the grouting pressure is, the larger the grouting flow rate is, the smaller the pullback speed of the drill boom is. The larger the deformation of the ground surface is, the maximum of the surface deformation is located just above the center of the horizontal jet grouting pile. For the common range of construction parameters, the maximum of surface deformation increases by 25.4% for every 10 MPa increase in grouting pressure; the maximum of surface deformation increases by 33.9% for every 50L · min-1 increase of grouting flow rate; With the increase of 5 cm · min-1, the maximum of surface deformation decreased by 20.7% on average. The normalized relationship between the deformation of surface bump and the horizontal distance of pile center indicates that 1% of pile diameter is the control value of construction influence range. The influence range of the rotary jet grouting pile construction is about 12 times of pile diameter. The engineering example shows that the method has strong rationality.