摘要
为掌握真空-堆载预压法处理软弱地基的加固机理和处理效果,采用Abaqus有限元软件对真空-堆载联合预压荷载下的吹填土进行数值模拟与分析,计算了土体的沉降、水平位移和超静孔隙水压力,并与实测结果进行对比分析。结果表明:采用大变形和小变形理论计算所得地基的沉降、水平位移以及超静孔隙水压力与实测数据吻合较好,且大变形理论计算值更接近于实测结果,验证了将塑料排水板转换成砂墙进行计算是可行的;真空预压阶段的吹填土在加固区以内产生收缩变形而加固区以外则为剪切变形;真空-堆载联合预压阶段的加固区以外土体仍向加固区内部产生收缩变形,随着堆载的增加,加固区以外的土体会产生向上的隆起变形,井阻效应对加固区土体的超静孔隙水压力分布有较大影响;地面堆载的施加会使塑料排水板范围以外的土中超静孔隙水压力分布出现明显的曼德尔效应。
In order to reveal the consolidation mechanism and efficiency of ground improvement by the combined vacuum and surcharge preloading method,the Abaqus software is used to simulate and analyze the dredger fill improved by combined vacuum and surcharge preloading.The deformation and excess pore pressure of dredger fill are calculated using the theories of large deformation and small deformation.The calculation results are compared with the field test data.The results show that the general change trend of the settlement curve,horizontal displacement,and excess pore pressure of dredger fill calculated using the theories of larger deformation or small deformation are similar to the field test data,and the values calculated by large deformation theory are closer to the field test data.The feasibility of the calculation method of converting prefabricated vertical drain into sand wall is verified.Under the vacuum preloading stage,the dredger fill mainly produces contraction deformations while the soil outside the vacuum area mainly produces shear deformations.In the combined vacuum and surcharge preloading stage,the soil still produces contraction deformations towards the area of reinforced soil.With the adding of surcharge preloading,the soil outside the reinforced area is uplifted.The effect of well resistance has great influence on the distribution of excess pore pressure in the reinforced area.The surcharge preloading can cause the Mandel-Cryer effect in the distribution of excess pore pressure in the zone outside the prefabricated vertical drainage.
作者
沙玲
刘鸿
王国才
SHA Ling;LIU Hong;WANG Guocai(Department of Architectural Engineering,Zhejiang College of Construction,Hangzhou 311231,China;Institute of Geotechnical Engineering,Zhejiang University of Technology,Hangzhou 310023,China)
出处
《浙江工业大学学报》
CAS
北大核心
2021年第2期140-146,共7页
Journal of Zhejiang University of Technology
基金
浙江省科技厅公益性技术应用研究项目(2017C31011)
浙江省大学生科技创新(新苗人才)计划项目(2018R403068)。
关键词
吹填土
真空-堆载联合预压
变形
超静孔隙水压力
曼德尔效应
dredger fill
combined vacuum and surcharge preloading
deformation
excess pore pressure
Mandel-Cryer effect
