不同含水率条件下EPS颗粒轻量土蠕变特性试验研究

发布时间：2018-05-08 21:25

本文选题：轻量土 + 含水率　；参考：《工程地质学报》2017年01期

【摘要】：为了得到轻量土路基中央部位在长期荷载作用下的蠕变规律,通过单向固结蠕变试验,分析了不同含水率EPS颗粒轻量土、素土在不同轴向压力下的蠕变特性。研究表明:固定其他因素,轴向压力越大,含水率越高,土样蠕变变形越大。轻量土加载1d基本上可以达到总变形的93%~98%,蠕变变形具有明显的衰减特征。轻量土是一种结构性土体,与素土蠕变机理完全不同。当轴向压力小于压缩屈服应力时,轻量土蠕变变形主要是孔隙闭合、水分的排出、固体颗粒移动的结果;当压力大于压缩屈服应力时,轻量土土样原有结构被破坏,EPS颗粒自身会被压缩。基于土体衰减蠕变特征,本文依据双曲线模型建立了轻量土经验蠕变模型,基本上可以反映路基中央部位轻量土的蠕变规律,经验模型适用于轻量土条件为轴向压力小于土体压缩屈服应力。试验与理论计算分析表明,轻量土固结特性优于素土,路基沉降在施工过程中就可以达到稳定,运营期间的工后沉降基本可以忽略。
[Abstract]:In order to obtain the creep law of the center part of lightweight soil roadbed under long-term load, the creep characteristics of lightweight soil with different moisture content EPS particles under different axial pressures were analyzed by unidirectional consolidation creep test. The results show that the higher the axial pressure, the higher the moisture content and the greater the creep deformation of the soil sample. The creep deformation of the lightweight soil can reach 933 ~ 98% of the total deformation after one day of loading, and the creep deformation has obvious attenuation characteristics. Lightweight soil is a kind of structural soil, which is completely different from the creep mechanism of plain soil. When the axial pressure is less than the compressive yield stress, the creep deformation of lightweight soil is mainly due to the closure of pores, the discharge of water and the movement of solid particles, and when the pressure is greater than the compressive yield stress, The original structure of lightweight soil samples is destroyed and the EPS particles themselves will be compressed. Based on the characteristics of attenuation creep of soil mass, the empirical creep model of lightweight soil is established based on hyperbolic model, which can basically reflect the creep law of lightweight soil in the central part of roadbed. The empirical model is suitable for lightweight soil conditions where the axial pressure is less than the compressive yield stress of the soil. The experimental results and theoretical analysis show that the consolidation property of lightweight soil is better than that of plain soil, the settlement of roadbed can be stabilized during construction, and the settlement after construction can be neglected.
【作者单位】：西北农林科技大学水利与建筑工程学院;里海大学土木与环境工程系;
【基金】：国家自然科学基金项目(51509211) 西北农林科技大学博士点基金项目(2011BSJJ084);西北农林科技大学大学生创新训练项目(201410712093)资助陕西省自然科学基金项目(2012JQ7013) 中央高校基本科研业务费专项资金项目(QN2012025) 陕西省专项配套经费项目(Z109021108) 陕西省社会发展科技攻关项目(2015SF260) 国家留学基金项目(201406305047)
【分类号】：U416.1

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