软土地基CFG桩加固技术

通过单桩及复合地基静载荷试验、静力触探、低应变动力测试、沉降观测等现场测试技术, 研究了低置换率CFG (CementFlyashGravel) 桩处理软土地基的加固效果, 阐述了设计方法和施工技术措施。研究显示, 处理后的复合地基承载力比天然地基承载力提高了1 4~2 0倍; 低置换率CFG桩对桩间土无挤密作用; 保证工后沉降为50mm的所需固结时间, 短桩段复合地基不超过0 5a, 长桩段不超过1 0a, 且短桩段地基固结速率大于长桩段。结果表明, 低置换率CFG桩能满足软土路基承载力和工后沉降要求。

CFG pile strengthening technology of soft ground

This paper studied CFG pile strengthening effect of soft ground, which has low replacement ratio, with multiple field-testing techniques, such as static cone penetration test, plate loading test, low strain dynamic testing and settlement observation. The design method and construction technology of CFG pile were also represented concisely. It is pointed that the bearing capacity of composite foundation after treatment is 1.4~2.0 bold that of natural ground, CFG pile can not compact the soil between piles, in order to guarantee the consolidation time of settlement (50 mm) after projection, it needs no more than 0.5 year to reach the specified settlement for the zone used short piles, and no more than 1.0 year for the zone used long piles, and the rate of consolidation in the zone used short piles is higher than in the zone used long piles. The results indicate that this kind of CFG pile can guarantee bearing capacity and settlement after projection criterion of soft ground.