真空预压复合土钉支护在软土基坑中的运用研究

土钉墙以其众多优点广泛用于基坑工程,但在软土地区的运用有很大的局限性。在经过真空预压加固后的软土地基上进行深基坑土钉支护的可行性值得探讨。本文研究基于真空预压土体强度增长规律,用十字板剪切强度推求软粘土抗剪强度指标方法,按规范要求并考虑到软土地区深基坑土钉支护的特殊性进行土钉支护设计,分析真空预压联合土钉支护技术解决软土深基坑土钉支护外部稳定问题的原理。研究结果表明:经真空预压加固后,土体强度得到较大增长,土钉墙外部稳定性成倍提高,钉土界面粘聚强度显著增加,说明真空预压联合土钉支护技术运用于深基坑是可行性的。

Study on foundation pit supporting by soil nails in soft clay improved by combined vacuum preloading

Soil nail wall is widely used in excavation engineering for its advantages, but limitations must be considered when being used in soft soil area. The feasibility of deep foundation pit braced by soil nailing after vacuum preloading is a worthy topic. Based on the soil strength growth rule of vacuum preloading, an approach is employed to deduce shear strength parameters from vane-shear strength to study the strength of treated soil by combined vacuum preloading. The study would analyse the feasibility of the deep foundation pit using and soil nail. After being treated by vacuum preloading, the soft soil strength is well improved, which enhance the exterior stability of soil nail wall and significantly increase interface bond strength between soil nail and soft soil. the study results show that it is feasible for the deep foundation pit using combined vacuum and soil nail in soft soil area, and reference and practical value can be drawn from the article.