软土地层双液微扰动注浆浆液扩散规律试验研究

Experimental Study on Diffusion Law of Double-liquid Micro-disturbance Grouting in Soft Soil

摘要:

依托软土地区某深基坑项目开展原位双液微扰动注浆试验，结合实时监测、静力触探、现场开挖等手段，探究浆液在软土地层中的扩散范围，剖析浆脉在扩散范围内的劈裂-挤密形态，揭示单孔沿深度连续注浆条件下周围土体位移、应力及孔隙水压力等随时间和空间的变化规律。研究表明，注浆引起的孔周土体侧向位移、水压力和土压力随距离呈现幂级数衰减规律，且在2m范围内急剧衰减；开挖所得浆脉最远扩散至2.5m，在距注浆孔0.5m范围内以充填挤密为主，在1m范围外以劈裂为主，且距注浆孔1m以外的实测浆脉和理论注浆量体积比与按土体侧向位移计算体积膨胀率基本吻合。研究结果可为软土盾构隧道的注浆纠偏提供现场试验依据和实测数据参考。

Abstract:

This study is based on a deep foundation pit project in a soft soil area， conducted in-situ micro-disturbance double-liquid grouting experiments. By integrating real-time monitoring， static cone penetration tests， and on-site excavation methods， the study explores the grout diffusion range in soft soil strata. It also analyzes the fracture-compaction morphology of grout veins within the diffusion range and reveals the spatial and temporal variations in surrounding soil displacement， stress， and pore water pressure during continuous grouting along the depth of a single borehole. The findings demonstrate that the lateral displacement of the soil， pore water pressure， and soil pressure induced by grouting follow a power-law attenuation with distance， with rapid decay within 2 m. Excavation results showed that grout veins extend as far as 2.5 m， primarily exhibiting compaction filling within 0.5 m of the grouting borehole and fracturing beyond 1 m. Moreover， the measured grout volume beyond 1 m aligns with the theoretical volume expansion ratio calculated through inclinometer readings of soil deformation. These results provide a solid experimental basis and extensive data reference for grouting corrections in soft soil shield tunnels.