不同加固形式下海上深层水泥搅拌桩复合地基海堤的三维数值模拟分析  

Three-dimensional numerical analysis of deep cement mixing pile composite foundation seawall with different improvement patterns

作　　者：何洪涛[1] 王征亮[1] 林佑高[1] 谢万东[1] HE Hong-tao;WANG Zheng-liang;LIN You-gao;XIE Wan-dong(CCCC-FHDI Engineering Co.,Ltd.,Guangzhou,Guangdong 510230,China)

机构地区：[1]中交第四航务工程勘察设计院有限公司,广东广州510230

出　　处：《中国港湾建设》2022年第2期32-37,共6页China Harbour Engineering

摘　　要：海上深层水泥搅拌法可有效提高边坡稳定性、减小工后沉降、增大地基承载力,达到地基改良的目的。但目前对深层水泥搅拌法加固边坡稳定的破坏模式认识不足,传统复合地基稳定性计算方法仅考虑桩体与桩间土的加权平均抗剪强度,易高估其稳定安全系数。通过开展海上深层水泥搅拌法加固深厚软土地基海堤的三维数值模拟分析,对比不同布置形式的水泥搅拌桩复合地基的变形及受力状态,研究了失稳过程中的潜在滑动面形态、破坏模式及塑性区发展规律。研究表明,水泥土搅拌桩复合地基根据其加固形式的不同,存在两种明显不同的破坏模式。边坡失稳过程中,深层水泥搅拌桩由于承受水平推力,桩式布置的水泥土桩体主要表现为弯曲破坏和压缩-剪切模式,水平位移较大,整体稳定安全系数较低;壁式布置的水泥土剪力墙主要表现为整体剪切破坏模式,水平位移较小,整体稳定安全系数较高。The offshore deep cement mixing(DCM)method can enhance slope stability,reduce settlement,and increase bearing capacity of the soft ground,so as to achieve the purpose of foundation improvement.However,the evaluation of slope stability of DCM ground is still a concern in practice due to a lack of well understanding of its failure mode.The conventional stability calculation method of composite foundation only considers the weighted average shear strength of DCM piles and soft soil,which would overestimate the factor of safety against slope stability.Through the three-dimensional numerical analysis of DCM method for improving deep soft soil seawall,the deformation and stress state of cement mixing pile composite foundation with different improvement patterns were compared,and the shape of potential sliding surface,failure mode and the development law of plastic zone in the process of instability were studied.The results indicate the DCM pile composite foundation has two different failure modes according to the different patterns.In the process of slope stability,due to the lateral loading of DCM piles,it shows the result of a bending failure and compression-shear failure in the group type DCM piles with excessive displacement and lower factor of safety,and an overall shearing failure in the wall type DCM piles with minor displacement and higher factor of safety.

关 键 词：海上深层水泥搅拌法 软土地基 边坡稳定 

分 类 号：U655.544[交通运输工程—港口、海岸及近海工程]