水泥固化滨海风积砂力学特性试验及细观数值仿真

发布时间：2018-01-07 11:30

本文关键词：水泥固化滨海风积砂力学特性试验及细观数值仿真　出处：《岩土工程学报》2016年11期 　论文类型：期刊论文

【摘要】：滨海风积砂因结构松散、自稳能力差、级配不良不易压实,被视为一种特殊土。水泥固化是常用的加固手段,而水泥剂量对风积砂力学性能的影响规律及细观作用机制目前尚不清楚。利用GDS土工三轴试验仪,对不同水泥剂量(0%,4%,6%)的水泥固化滨海风积砂进行不同有效围压(50,100,150 k Pa)下的CD试验。结合室内试验数据和水泥砂样显微照片,建立水泥固化滨海风积砂细观结构的颗粒流PFC2D模型,进行三轴试验的细观数值仿真分析。研究结果表明,水泥固化滨海风积砂应力应变关系呈应变软化型,水泥剂量对滨海风积砂强度贡献明显,对体变影响相对较小。采用颗粒平行黏结方式的颗粒流数值仿真能有效反映水泥固化滨海风积砂的细观力学特性,水泥剂量对水泥固化滨海风积砂的黏结破坏数、配位数、位移场均有显著影响。
[Abstract]:Coastal aeolian sand is regarded as a kind of special soil because of its loose structure, poor self-stability and poor gradation, so it is regarded as a special soil. Cement solidification is a commonly used reinforcement method. However, the influence of cement dosage on the mechanical properties of aeolian sand and the mechanism of mesoscopic action are not clear. Using the GDS geotechnical triaxial test instrument, 4% of different cement dosages can be obtained. (6) cement solidified coastal aeolian sand was used for CD test under different effective confining pressures of 50 ~ 100 ~ 150kPa). Combined with laboratory test data and microphotographs of cement sand sample. The particle flow PFC2D model of cement-solidified coastal aeolian sand was established, and the mesoscopic numerical simulation of triaxial test was carried out. The stress-strain relationship of cement-solidified coastal aeolian sand is strain softening type, and the cement dosage has a significant contribution to the strength of coastal aeolian sand. The particle flow numerical simulation of particle parallel bonding can effectively reflect the meso-mechanical properties of cement-solidified coastal aeolian sand. The cement dosage has a significant effect on the number of bond failure, coordination number and displacement field of cement-solidified coastal aeolian sand.
【作者单位】：华侨大学福建省隧道与城市地下空间工程技术研究中心;重庆交通大学水利水运工程教育部重点实验室;
【基金】：国家自然科学基金项目(51679093,51308234,51408242) 2015年福建省新世纪优秀人才支持计划项目重庆交通大学国家内河航道整治工程技术研究中心暨水利水运工程教育部重点实验室开放基金项目(SLK2014A02)
【分类号】：TU441
【正文快照】： 风积砂具有结构松散、保水性和自稳能力差、颗粒均匀、级配不良且不宜压实等特性,若直接使用风积砂作为地基土,整体性差,地基承载力较低。水泥固化可形成整体性较好的水泥胶结砂土,常用于公路基层或底基层。已有的试验研究表明,水泥剂量对水泥固化砂土的内摩擦角、黏聚力等宏

【相似文献】