断桩对CFG桩复合地基路基稳定性影响的研究

Study of Influence of Broken Piles on Stability of Embankment with CFG Piles Composite Foundation

工程实践表明,CFG桩复合地基断桩率较高,利用离心模型试验研究了断桩对CFG桩复合地基路基稳定性的影响。研究表明,断桩对复合地基沉降和位移发展规律、滑动面形状基本没有影响;路基滑动面内断桩和正常桩均在软土层底部桩受弯破坏,正常桩在软土层中部附近产生软土层底部相反的受弯断裂,大部分断桩在软土层中部附近未断裂;CFG桩断裂后仍能承担一定的竖向荷载并提高路基稳定性;断桩复合地基路基的沉降、隆起、位移、路基开裂对应加速度、轴力峰值对应加速度等均介于天然地基路基和正常桩复合地基路基之间并接近天然地基路基。

Some projects have shown that ratio of broken CFG piles is quite high,so influence of broken piles on stability of embankment with CFG piles composite foundation has been studied through centrifugal model tests. It has shown that broken piles have little influence on developing law of settlement and displacement,or shape of slide surface of embankment. Broken piles and normal piles within side surface are all bent broken near bottom of soft clay stratum. Normal piles within slide surface are also bent broken near middle of soft clay stratum and most broken piles within slide surface aren’t broken near middle of soft clay stratum. Broken piles can bear some vertical load and enhance stability of embankment. Settlement,swell,deformation,accelerations corresponding to cracking of embankment and axial force peak of embankment with broken pile composite foundation are all between those of embankment with normal pile composite foundation and embankment with natural foundation and are near the latter.