CFG桩加固软土路基参数敏感性数值分析  

Numerical analysis on parameter sensitivity of soft soil subgrade strengthened by CFG pile

作　　者：杨川陵 谢晓琴[2] YANG Chuan-ling;XIE Xiao-qin(Guangzhou Transportation Design and Research Institute Co.,Ltd.,Guangzhou 510030,China;School of Management Science and Real Estate,Chongqing University,Chongqing 400045,China)

机构地区：[1]广州市交通设计研究院有限公司,广东广州510030 [2]重庆大学管理科学与房地产学院,重庆400045

出　　处：《湘潭大学学报（自然科学版）》2021年第2期95-102,共8页Journal of Xiangtan University(Natural Science Edition)

基　　金：国家重点研发计划(2019YFB0303635)。

摘　　要：交通建设中对路基工程要求较高,选择满足交通建设需求的路基设计参数是工程建设的重要环节.为此,该文设计了CFG桩加固软土路基参数敏感性数值分析方法.以某处于剥蚀丘陵间丘间谷区域的公路工程为目标,采用弹塑性有限元法,以四节点实体单元模拟土体,依据土体弹塑性蠕变现象塑造其本构模型,且土体屈服条件选择服从摩尔-库伦准则,利用结构单元和线弹性模型模拟CFG桩、桩帽和路基填土、垫层,在动力荷载条件下分析CFG桩加固软土路基参数敏感性数值.分析结果显示:路基竖向速度均出现降低趋势,不同区域降低幅度有所差异;CFG桩结构刚度与填土荷载下路基沉降之间呈反比例相关,刚性结构柔性结构相比,路基沉降降低45%以上;利用CFG桩加固后,土体沉降主要为蠕变导致的次固结沉降.In traffic construction,there are higher requirements for Subgrade Engineering,so it is an important part of engineering construction to select subgrade design parameters to meet the needs of traffic construction.In this paper,a numerical analysis method for parameter sensitivity of soft soil subgrade strengthened by CFG pile is designed.Aiming at a highway project in Eroded Hilly valley area,the elasto-plastic finite element method is used to simulate the soil with four node solid element.According to the elasto-plastic creep phenomenon of soil,the constitutive model is established.The yield condition of soil obeys Mohr Coulomb criterion.The structural element and linear elastic model are used to simulate CFG pile,pile cap,subgrade filling and cushion.The parameter sensitivity of the soft soil subgrade strengthened by CFG pile is analyzed.The analysis results show that:the vertical velocity of subgrade has a decreasing trend,and the decreasing range is different in different areas;the stiffness of CFG pile structure is inversely proportional to the subgrade settlement under the filling load,and the subgrade settlement is reduced by more than 45%compared with the rigid structure and flexible structure;after using the CFG pile reinforcement,the soil settlement is mainly the secondary consolidation settlement caused by creep.

关 键 词：CFG桩 软土路基 参数敏感性 数值分析 模型假定 路基沉降 

分 类 号：U238[交通运输工程—道路与铁道工程]