高聚物布袋注浆桩成桩规律试验研究

高聚物布袋注浆桩是针对既有建筑物地基加固工程而开发的一种新型地基加固技术。为探讨该新技术对既有建筑物地基加固工程的适用性,通过不同密度及不同分层情况土体中的注浆成桩试验,研究了高聚物布袋注浆桩的施工工艺、成桩规律和加固效果等内容。试验结果表明:高聚物布袋桩挤密土体效果明显,成桩后桩径可达到2~3倍预钻孔直径;在相同注浆量的条件下,桩径随着土体密度的增大而减小,桩体密度随着土体密度的增大而增大;同时,高聚物布袋注浆桩能很好地通过硬质夹层,形成哑铃形桩体,对软土地基起到明显的加固作用。现场轻型动力触探试验结果表明,经高聚物布袋注浆桩加固处理后的土体,轻型动力触探试验的锤击数平均增加2~3次,提高了30%~50%,加固效果显著,充分论证了高聚物布袋注浆桩用于加固软弱地基的可行性。

Experimental Research on Polymer Grouting Bag Pile

The polymer grouting bag pile is a new type of foundation reinforcement technology developed for the foundation reinforcement of existing buildings. In order to explore the applicability of polymer grouting bag pile to the foundation reinforcement of existing buildings, we investigated into the construction technology, law of pile formation and reinforcement effect of polymer grouting bag pile through the experiment of grouting pile in soil with different densities and layering conditions. The experimental results demonstrated that polymer bag pile has obvious effect on compacting soil mass. After piling, the pile diameter can reach 2D-3D (D represents the diameter of drilling hole). In the presence of the same grouting quantity, the pile diameter shrinked with the increase of soil density, while the pile density expanded with the increase of soil density. Meanwhile, polymer grouting bag pile can also pass through the hard interlayer to form a gourd-shaped body and plays a better role in strengthening the soft soil foundation. The results of field light dynamic penetration test showed that the hammer stroke of light dynamic penetration test increased by 2-3 times in the soil reinforced by polymer grouting pile, an improvement of 30%-50%. Therefore, polymer grouting bag pile has good reinforcement effect and is feasible for strengthening weak foundation.