粉细砂地层结构松散，隧道施工难度大，易坍塌，通过引进改性水玻璃，实现风积粉细砂层的注浆效果，采用长管棚加注浆小导管加改性水玻璃超前支护技术，提高粉细砂层自稳性，控制围岩变形。该文分析了长管棚加注浆小导管加改性水玻璃超前支护组合作用机理，阐述了改性水玻璃的性能、固结原理及其在粉细砂层中的可注性，通过试验确定了改性水玻璃的最优配兑及其力学参数，给出改性水玻璃的选取、注浆施工关键工艺及施工技术要点，为粉细砂地层改良加固提供借鉴。

The silty sand stratum has loose structure, making tunnel construction difficult and easy to collapse. By introducing modified water glass, the grouting effect of aeolian silty sand layer is realized. The advanced support technology adopts a long pipe shed, small pipe and modified water glass to improve the self-stability of silty sand layer and control the deformation of surrounding rock. The combined action mechanism of the long pipe shed, small pipe and modified water glass advance support is analyzed. The properties, consolidation principle and the injectability of modified water glass in the silty sand layer are described. The selection of modified water glass, key process of grouting construction and main points of construction technology are given through experiments. It provides reference for the improvement and reinforcement of the silty sand stratum.