基于CEL法的钻孔灌注桩后注浆加固数值模拟及承载力分析

Numerical simulation and bearing capacity analysis of post-grouting reinforcement of bored piles based on CEL method

为探究后注浆加固土层对钻孔灌注桩承载力的影响规律,以江苏省南通市某工程为背景,基于耦合欧拉-拉格朗日方法(CEL法),采用ABAQUS有限元软件建立了后注浆钻孔灌注桩精细化有限元模型,对压密注浆过程进行了全过程仿真模拟,发现浆体的扩散形状更趋向于水滴型。将模拟结果与理论值、试验值进行比较,认为CEL法模拟可以作为对实际注浆过程浆体成型的有效参考。同时基于注浆结果,对是否采用后注浆的钻孔灌注桩承载力进行分析,将承载力模拟结果与江苏省南通市某工程后注浆钻孔灌注桩的单桩竖向抗压静载荷试验结果进行了对比,证明了数值模拟结果的准确性。模拟结果从数值仿真的角度为浆体固化后形状的确定提供了依据,可为相关工程应用及分析提供参考,同时定量分析结果从机理上证明钻孔灌注桩后注浆能有效提高桩的承载力。

In order to investigate the influence of post-grouting reinforced soil layer on the bearing capacity of bored grouting piles,a project in Nantong City,Jiangsu Province was explored.A finite element model of post-grouting bored grouting piles was established based on coupled Euler-Lagrange method(CEL method)using ABAQUS finite element software.Subsequently,simulation of the whole compaction grouting process was carried out,and it was found that the diffusion shape of the slurry tended to be of the water-drop type.Comparing the numerical results with the theoretical results and observed results,it is found that the numerical simulation based on CEL method can be used as an effective reference for the analysis of the actual grouting process.At the same time,the bearing capacity of the bored pile with or without post-grouting was analyzed based on the grouting results.The numerical results of bearing capacity of the bored pile were compared with the results of vertical compressive static load test of single pile of post-grouting bored pile in a project in Nantong City,Jiangsu Province,which proved the accuracy of numerical results.The numerical results provided a basis for determining the shape of the slurry after curing from the perspective of numerical simulation,which can provide a reference for relevant engineering applications and analysis.At the same time,the results of quantitative analysis proved mechanically that post-grouting of bored piles can effectively improve the bearing capacity of piles.