注浆压力对非挤土管桩后注浆效果的影响研究

Study on the Influence of Grouting Pressure on the Grouting Effect of Non-squeeze Out Soil Pile

非挤土管桩后注浆浆液在桩-土间隙中流动效果及在土体中扩散效果直接关系到桩基摩阻力及极限承载力,为此本文建立了桩侧注浆液流动扩散数学模型,研究了注浆压力对注浆管中浆液流场、桩-土间隙中浆液流场、桩-土间隙中浆液浓度等的影响,分析了注浆过程中土体的应力分布特征及土体中浆液的扩散半径,得到了如下结论:随着注浆压力的增加,注浆管内和桩-土间隙内浆液最大速度、浆液在土层中的最大扩散半径,均呈现增加趋势;注浆压力超过一定值后,持续增加注浆压力,对注浆效果的提升有限;距离出浆口越远,注浆体的厚度越小;注浆压力越大,注浆体厚度越大、土层的最大应力也越大、桩体及土层的位移也越大。研究成果为工程实践中设计更加科学、合理的注浆技术方案提供了重要的理论基础。

The flow effect of grout in the pile-soil gap and the diffusion effect in the soil during post grouting of non squeezed soil pipe piles directly affect the frictional resistance and ultimate bearing capacity of the pile foundation.Therefore,a mathematical model for the flow and diffusion of grout on the pile side is established.The influence of grouting pressure on the flow field of grout in the grouting pipe,the flow field of grout in the pile-soil gap,and the concentration of grout in the pile-soil gap are studied.The stress distribution characteristics of the soil and the diffusion radius of grout in the soil during the grouting process are analyzed,and the following conclusions are obtained:As the grouting pressure increases,the maximum velocity of the grout in the grouting pipe,the maximum velocity of the grout in the pile-soil gap,and the maximum diffusion radius of the grout in the soil layer all show an increasing trend.After the grouting pressure exceeds a certain value,continuously increasing the grouting pressure has limited improvement on the grouting effect.The farther away from the grout outlet,the smaller the thickness of the grout.With the increase of grouting pressure,the maximum stress of the soil layer shows a non-linear increasing trend,the displacement of the pile and soil layer also shows a non-linear increasing trend.The research results provide an important theoretical basis for designing more scientific and reasonable grouting technology schemes in engineering practice.