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1 工程概况与有限元模型
该工程场地填筑面积约14.3万m 2,地块软基处
理面积约 109.8万m 2。该场地市政道路共 16条: 7条次
干路和9 条支路,设计总长18 180.1 m,道路范围内桥
涵共11座。排洪渠2 条,长2 467 m;截洪沟2 条,长
2 465 m;截洪沟山体支护长1 733 m。该路段地基土
层及对应土体计算参数,见表 1。利用路基模型对称
性、中心为对称轴,取整个软土地基一半建立几何模
型。计算模型几何参数与施工时基本相同,即路基顶
面宽度40 m、路基宽度20 m(计算断面对称)。考虑
到真空 –堆载联合预压对水向环境影响,计算模型水
平向影响范围取自路基底缘向外延伸80 m,考虑到真
空 –堆载联合预压影响深度,取基本不受影响的粉砂
层厚度50 m,相当于被影响深度范围2 倍。塑料排水
板厚度4.5 mm,间距1.1 m,总长23 m。
真空-堆载联合预压加固道路软基过程研究
姜立宝
(中国铁建港航局集团有限公司总承包分公司,广东珠海 519000 )
[摘 要 ] 采用ABAQUS有限元软件模拟珠三角洪湾港北片区典型软土地基真空– 堆载联合预压加固过
程,验证此类工程数值模拟可行性。基于已建数值模型,分析不同堆载时间间隔和堆载速率时软基加固区
边界点位移变化。结果表明:有限元计算所得地基沉降规律、沉降量与实测结果吻合度较高;堆载时间间
隔对加固区变形影响不大;施工过程保证规范要求最小时间间隔(10 d),连续堆载使加固区更快固结,减
少抽真空时间;较高堆载速率能加速固结,节约抽真空时间,但可能引起堆载过程中地基失稳现象。选取
堆载速率20 d/级,既可保证较短抽真空时间,又可避免堆载过程产生失稳现象。
[关键词 ] 道路软基;真空–堆载预压;有限元;堆载时间;堆载速率
[中图分类号] U 416 [文献标志码] A [文章编号] 1001 -523X (2023 )11-0158 -04
STUDY ON INFLUENCING PROCESS OF VACUUM-SURCHARGE PRELOADING REINFORCED
SOFT ROADBED
Jiang Li-bao
[Abstract ] The feasibility of engineering numerical simulation is verified by ABAQUS software on selected
soft roadbed (north area at Hongwan port in Zhuhai, China) reinforced with combined vacuum-surcharge preloading
method. The displacement of reinforced soft ground at varying surcharge time intervals and rates is analyzed
on the established numerical model. The obtained results show that the ground settlement obtained by the finite
element calculation agree well with the measured in-situ data. The surcharge time interval has slight impact on the
deformation of reinforced area, and the minimum time interval (10 d) is required by the construction specification.
Especially, the continuous loading mode can accelerate the consolidation and reduce the vacuum time. Higher
surcharge rate speeds up the consolidation and saves the vacuum time, but may cause ground instability during
loading. The surcharge loading rate is 20 d/step to ensure a short vacuum time and avoid surcharge instability.
[Keywords ] roadbed on soft ground;vacuum-surcharge preloading;finite element;surcharge time;surcharge
loading rate
收稿日期 :2023–07–25
作者简介 :姜立宝(1983—),男,黑龙江哈尔滨人,高级工程
师,主要研究方向为地基处理等技术研究。
表1 加固区地层物理力学参数
土层 重度 / (kN/m3)
弹性模量/MPa 泊松比 渗透系数 / (cm/s
真空-堆载联合预压加固道路软基过程研究(论文).pdf