基于土体非线性压密效应的劈裂注浆机制分析

Split grouting mechanism based on nonlinear characteristics of compression process of soil

土体劈裂注浆过程伴随着劈裂通道两侧土体的压缩,而土体的压缩过程表现出明显的非线性特征。基于此,建立描述土体非线性压缩特征的应力–应变关系模型,该模型的参数可通过常规试验参数确定;将劈裂注浆扩散过程简化为平面辐射圆,考虑浆液流场与土体应力场耦合作用的影响,建立基于土体非线性压缩?-p模型的劈裂注浆扩散理论模型,推导劈裂通道宽度的空间分布方程,进而得到注浆压力、劈裂通道宽度、浆液扩散半径三者之间的关系。通过与常规土体线性压缩模型所得计算结果进行比较,说明考虑土体压缩非线性特征的必要性;开展了劈裂注浆模型试验,试验结果表明浆脉厚度由注浆孔沿扩散半径衰减,最大浆脉厚度计算值与试验测量值处于同一数量级,验证了理论的合理性。

In the process of split grouting,the soil on both sides of the split channel is being compressed. The relationship between the stress and strain is nonlinear in the compression process of soil. A new model of relationship between the soil stress and strain was established to describe the nonlinear characteristics in the compression process of soil. The process of split grouting was simplified into the horizontal radiation circle. Based on the nonlinear model of compression and considering the coupling effect at the interface between soil and slurry,a theoretical model of split grouting was established. The spatial distribution equation of width of the split channel was derived,and the relationship among the grouting pressure,width of split channel and radius of grouting diffusion was obtained. After comparing with the result from the linear relationship of stress and strain,the nonlinear relationship of stress and strain was shown to be necessary. The model test of split grouting process was performed. The width of split channel attenuated along the diffusion radius. The calculated and measured the thickness of grouting vein are at the same order of magnitude and theory was thus proved reasonable.