CFG桩和抛石挤淤加固软土地基的试验研究

Experimental Research on the Soft Soil Reinforced by CFG Pile and Dumping Rockfill

研究目的:CFG桩和抛石挤淤常用于软土地基加固,高等级公路对其加固后的工后沉降提出严格要求。为探讨CFG桩和抛石挤淤加固浅层软土地基的效果,在兰永一级公路加固段进行工后沉降现场监测,分别在行车道和路肩位置CFG桩桩顶、抛石顶面及CFG桩桩间布置单点沉降计,监测工后沉降变化情况,对比分析CFG桩桩顶和抛石顶面沉降随时间和空间的变化规律,并分析CFG桩桩间不同深度地基的沉降变化规律。研究结论:(1)CFG桩和抛石挤淤加固的软土地基沉降随时间增加而增大;(2)路肩位置沉降大于行车道位置沉降;(3)CFG桩桩间地基分层沉降随深度增大而变小,CFG桩桩顶沉降小于抛石顶面沉降,CFG桩加固浅层软土地基效果优于抛石挤淤,且沉降稳定较快;(4)本研究成果可为软弱路基加固设计和施工提供指导。

settlement Research purposes： CFG pile and dumping rockfill are often of expressway subgrade have strict rules to the soft foundation used for the reinforcement of soft soil, and the treatment. To explore the effect of the CFG pile and dumping rockfill reinforcement for shallow soft subgrade, experimental research on the settlement is carried out on the Lanyong highway. Single -point settlement meter is embedded on the top of CFG pile and dumping rockfill in the driveway and shoulder position, the settlement is monitored after construction, the change rules of settlement with time and space are analyzed. Research conclusions： （ 1 ） The settlement of soft soil foundation reinforced by CFG pile and dumping rockfill increases with time. （2）The settlement of shoulder position is greater than the driveway position. （3）The settlement at different depths of CFG pile foundation decreases with the increase of depth, the settlement of CFG pile is less than dumping rockfill reinforcement subgrade, the reinforcement effect of the CFG pile is better than dumping rockfill, the stability of the shallow soft subgrade can be improved and the construction period can be shortened by ground improvement with CFG pile. （4）The research results can provide the guidances for design and construction of soft soil.