模型槽中模拟压密注浆的实验研究

Experimental Research of Simulated Pressure Grouting in Model Slot

在实际工程中,注浆理论研究落后于工程实践,普通渗透注浆模拟难以探究浆液在土中的产生和发展.本文基于模型槽注浆试验与理论分析的方法,针对在粉砂土体中注浆时水泥浆浆液的扩散性状、压滤效应、加固作用、土体力学指标对注浆孔扩张的影响等问题进行了研究,通过在模型槽中开展纯水泥浆注浆试验归纳总结了不同注浆参数对浆液扩散性状的影响.结果表明,浆液结石体与土体有明显分界面,水泥基浆液在饱和粉砂中扩散性状为压密-劈裂相伴随,浆液在扩散过程中,首先是小孔扩张过程,随后进入劈裂流动阶段,在较均质的土体中,垂直于小主应力的方向最容易被注浆压力克服,产生裂缝,形成浆脉.稠度较高的浆液有利于保证圆形注浆孔的扩张形成柱形浆泡.当采用较大的水灰比且注浆压力迅速上升时,土体中易产生水力劈裂现象,浆液劈裂土体形成片状浆脉.

In practical engineering,grouting theory research lags behind engineering practice,Ordinary penetration grouting simulation difficult to explore the slurry in the soil production and development. This article is based on the model slot grouting test and theoretical analysis method,the issues on Slurry diffusion characteristics,pressure filtration,reinforcement and impact of soil mechanics on cavity expansion during grouting were studied,the main contents are as follows：The effect of different grouting parameters on the diffusion characteristics of the slurry was analyzed by cementing grouting test in the model tank. The results show that the slurry body has interface with the soil obviously,and the diffusion properties of the cement-based slurry in the saturated fine sand are accompanied by the compaction-splitting phase. The higher consistency of the slurry is conducive to ensuring the expansion of the circular grouting hole to form a cylindrical pulp. When the soil has ants nest or earthworm hole pores,the slurry can be filled with compression and expansion of holes to form a network of stone body.