渣土改良技术是土压平衡盾构在砂层中掘进的关键。结合南昌、郑州和西安地铁区间隧道盾构施工实例，对土压平衡盾构砂性地层改良技术的应用进行系统的调查研究，采用膨润土泥浆、泡沫剂、聚合物等添加剂对不同的砂性地层进行渣土改良，分析膨润土泥浆、泡沫剂、泥浆与泡沫剂相结合、泥浆与聚合物相结合等对砂性地层改良的作用机制和特点，总结盾构在不同砂性地层中掘进采取的渣土改良技术措施，指出渣土改良技术目前的使用及研究现状，以期为今后类似工程提供参考和借鉴。

Ground conditioning is paramount for successful EPB tunneling in sand strata. Additives like bentonite slurry, foam and polymer are commonly used for ground conditioning in various sand strata, so as to guarantee safe and smooth tunneling. In the paper, the problems encountered during shield tunneling in sand strata in Nanchang, Zhengzhou and Xi’an are presented and the ground conditioning technologies used are described. The ground conditioning measures for shield tunneling in sand strata are summarized, and the stateofart of ground conditioning technology is discussed. 