长江科学院院报 ›› 2018, Vol. 35 ›› Issue (10): 126-130.DOI: 10.11988/ckyyb.20161233

• 岩土工程 • 上一篇    下一篇

交通荷载路径下超固结软黏土变形特性研究

郑华1, 杜运国1, 杨洋2   

  1. 1.温州市铁路与轨道交通投资集团有限公司, 浙江 温州 325000;
    2.哈尔滨工业大学(深圳) 土木与环境工程学院, 广东 深圳 518000
  • 收稿日期:2016-12-01 出版日期:2018-10-01 发布日期:2018-10-22
  • 作者简介:郑 华(1972-),男,浙江温州人,工程师,主要从事轨道交通方面的研究工作。E-mail:415608977@qq.com
  • 基金资助:
    浙江省建设厅科研项目(2015K156)

Deformation Behavior of Over-consolidated Soft Clay underTraffic Loading Stress Path

ZHENG Hua1, DU Yun-guo1, YANG Yang2   

  1. 1.Wenzhou Mass Transit Railway Investment Group Co., Ltd., Wenzhou 325000, China;
    2.School ofCivil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518000, China
  • Received:2016-12-01 Online:2018-10-01 Published:2018-10-22

摘要: 长期交通荷载作用下软基道路往往产生过大沉降,超载预压地基处理是目前控制沉降的有效方法。经超载预压处理后,路基软土表现出明显的超固结特性。利用GDS空心圆柱扭剪系统模拟交通荷载应力路径,对不同超固结比软黏土进行不排水循环加载试验,研究超固结比对软黏土应变发展规律、应力-应变滞回曲线发展规律、回弹模量发展规律的影响。试验结果表明:超固结作用可以限制循环荷载作用下软黏土累积应变的发展;当荷载一定时,土体的超固结比越大,循环荷载作用下的累积应变值就越小,孔压和累积应变达到稳定所需要的循环次数就越少;当荷载一定时,超固结比越大,应力-应变滞回曲线随循环次数的变化越不明显;土体的回弹模量越大,弹性特征越明显。

关键词: 超固结软黏土, 变形特性, GDS空心圆柱扭剪系统, 交通荷载, 累积应变

Abstract: Surcharge preloading, as an effective foundation treatment method, is usually adopted to reduce the large settlement of pavement constructed in soft clay subgrade caused by long-term traffic loading. After surcharge preloading, the soft clay performs apparent over-consolidated characteristics. Cyclic torsional shear tests are conduct on soft clay under different over-consolidation ratio through GDS hollow cylinder apparatus to study the effects of over-consolidation ratio on the development of axial cumulative strain, hysteretic-curve of stress-strain, and modulus of resilience. Test results suggest that over-consolidation restrains the development of cumulative strain of soft clay under cyclic loading. At given load, as over-consolidation ratio increases, the cumulative strain reduces, and the cycle number which stabilizes pore pressure and cumulative strain is smaller; and moreover, the hysteretic-curve of stress-strain changes less obviously with the proceeding of load cycle. In addition, larger modulus of resilience would give rise to a more explicit characteristic of elasticity.

Key words: over-consolidated, soft clay, deformation behavior, GDS hollow cylinder apparatus, traffic load, cumulative strain

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