摘要
采用三维有限元程序建立了一长为6 m、直径为0.8 m的加筋碎石桩复合地基流固耦合数值模型,分析了其在堆载和孔压消散过程中的荷载传递和变形特性。较传统碎石桩,加筋碎石桩复合地基桩土应力比显著增大,超孔压、沉降和桩身侧向变形显著减小,且随筋材刚度的增大,其性能进一步改善。加筋碎石桩复合地基在桩间土固结过程中产生明显的桩土差异沉降,形成土拱效应,使得堆载结束后桩土应力比变化很小。筋材长度对加筋碎石桩复合地基桩土应力比和沉降影响显著,应对其全长加筋才能保证桩体刚度和有效减少沉降。
A three-dimensional finite element seepage-coupling numerical modeling is performed on a 6m thick soft foundation reinforced by geosynthetic-encasement stone column (GESC) with diameter of 0.8 m. The load transfer mechanism and deformation characteristics of GESC composite foundation subjected to vertical loading and excess pore pressure dissipation are analyzed using the numerical model. Compared to conventional stone column (CSC) composite foundation, the stress concentration ratio (SCR) in GESC composite foundation apparently increases while the excess pore pressure, settlement and column shaft bulging apparently decrease. The performance of GESC is further improved with an increase of geosynthetic stiffness. An apparent differential settlement between column and surrounding soil emerges to form a soil arching during consolidation of the surrounding soil, which leads to little change in SCR values after loading. Reinforcement length is found to have a significant influence on SCR and settlement in GESC composite foundation. Full length reinforcement is required for GESCs in composite foundation to assure their entire stiffness and less settlement.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2013年第S2期393-399,共7页
Rock and Soil Mechanics
基金
中央高校基本科研业务费专项资金资助(No.0230219133)
关键词
加筋碎石桩
复合地基
软土
固结
数值分析
geosynthetic-encased stone column
composite foundation
soft clay
consolidation
numerical analysis
