基于Cvisc蠕变模型的CFG桩路基施工沉降分析  

Subgrade settlement using CFG piles based on cvisc creep model

作　　者：江宗斌[1] 姜谙男[1] 石静 

机构地区：[1]大连海事大学交通运输装备与海洋工程学院道桥所,辽宁大连116026 [2]大连市交通工程质量监督站,辽宁大连116037

出　　处：《岩土工程学报》2013年第S2期346-351,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51079010);大连市交通科技项目(2011-10);中央高校基本科研业务费资助项目:(2012TD015)

摘　　要：针对软土具有很强的流变特性,主要采用FLAC3D中的黏弹塑性模型Cvisc模拟软土路基在有蠕变参与和无蠕变参与沉降的对比。经过计算发现:蠕变20 a后路基沉降达到16 cm,而没有蠕变参与的路基沉降只有4 cm。软土路基蠕变位移占整个位移的一半以上。蠕变的过程其实是土体逐渐固结的过程,由于上部应力比较大,使得土体的沉降值继续增加。为防止沉降过大,对路基加CFG(水泥粉煤灰桩)进行处理,并且改用不同桩参数(桩长、弹性模量)后发现,桩的长度对于蠕变产生的影响要远远大于桩的弹性模量产生的影响。桩及褥垫层对于塑性区的影响较大,有利地减小了土体的破坏,使得土体的破坏区域集中在褥垫层附近,缩小了塑性区的范围。According to the obvious creep characteristics of soft soils, the Cvisc viswelasto-plasticmode of FLAC3D is employed to simulate subgrade settlement after construction, and the displacements with creep and no-creep are compared. The calculated results show that the displacement reaches 16 cm after 20 years' creep, and it is only 4 cm under no creep. The creep settlement is more half of the all. The course of creep is the process of gradual consolidtion. The creep effect makes the displacement continue to settle. To prevent the adjective settlement, CFG pile treatment(cement fly-ash piles) is performed for the subgrade. By changing the different pile parameters(pile length, elastic modulus), it is found that the influence of the pile length is greater than that of the elastic modulus. The piles and cushions have obvious influence on plastic zone. The destructive zone is gathered near the cushion, and soil mass failure and plastic zone are enormously reduced.

关 键 词：软土路基 蠕变 FLAC3D 黏弹塑性模型 CFG桩 

分 类 号：U416.1[交通运输工程—道路与铁道工程]