软粘土路基沉降的蠕变效应研究  

Study on creep properties of soft clay and settlement of subgrade

作　　者：李科锋[1] 谭儒蛟[2] 邱长林[1] 袁宇 

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300072 [2]天津市市政工程设计研究院,天津300072

出　　处：《水道港口》2017年第6期626-631,共6页Journal of Waterway and Harbor

摘　　要：天津滨海地区广泛分布深厚的软粘土,研究其蠕变特性对于预测该地区建筑工程的地基变形和长期稳定具有重要的意义。文章对天津滨海地区典型软粘土进行了一维固结蠕变试验,根据时间硬化蠕变定律建立了蠕变本构模型并确定了模型中的3个蠕变参数:应变率系数A、应力指数n和时间指数m。结合道路工程实践,运用有限元软件ABAQUS开展了路基沉降分析,对比了固结模型与蠕变模型的沉降量计算差异。研究表明,天津滨海地区软土的蠕变特性显著,考虑软土蠕变特性的路基沉降计算结果较固结模型大20%,且与工程实测结果吻合,软土蠕变导致的沉降量在道路工后沉降中占50%以上。The thick soft clay is widely distributed in Tianjin coastal region. It is significant to study creep properties of soft clay to predict the deformation and long-term stability of soil foundations in this area. In this paper,one-dimensional consolidation creep tests on typical soft clay of Tianjin coastal region were conducted and a constitutive model was established based on the time-hardening law. According to the experimental data,three creep parameters were determined,which were strain rate coefficient A,stress index n and time index m. Combined with a road project in Tianjin coastal region,a road settlement model considering both consolidation and creep of soft clay was established using the finite element software of ABAQUS. The embankment settlements between two different models were compared： One has considered the influence of creep,while the other has not. It is shown that the creep properties of this clay are obvious,for which the calculation result of embankment settlement considering the creep properties is in good agreement with the measured data. What＇ s more,the settlement of the calculation result is 1. 2 times the settlement only considering consolidation and the settlement caused by creep accounts for 50% of the final post-construction settlement.

关 键 词：软土 时间硬化蠕变定律 路基沉降 固结-蠕变 

分 类 号：TU471.8[建筑科学—结构工程]