| 摘要: |
| 【目的】探讨水泥用量、聚苯乙烯（Expanded Polystyrene，EPS）颗粒用量和振动次数对EPS颗粒混合轻量土动强度参数的影响，分析EPS颗粒混合轻量土的动强度参数特性，为EPS颗粒混合轻量土的推广使用提供参考。【方法】通过室内动三轴试验，以黄土作为原料土，在EPS颗粒用量为1.4，3.1，5.4，8.6，13.1，20.1 g/kg，水泥用量为100，150，200 g/kg的条件下制备不同原料用量EPS颗粒混合轻量土，设定固结应力为50，100，150和200 kPa，固结应力比Kc=1.0，振动次数为10，20，30，40，50，60，70，80，90和100，通过莫尔应力圆计算土体的总应力参数，采用5.0%压应变作为破坏标准选取相应的动强度，并分析水泥用量、EPS颗粒用量及振动次数对EPS颗粒混合轻量土动强度参数的影响。【结果】当固结应力比Kc=1.0时，不同原料用量EPS颗粒混合轻量土的动强度包络线均不经过原点，且在剪应力轴存在一定的截距。当水泥用量一定时，随着EPS颗粒用量的增大，EPS颗粒混合轻量土的动黏聚力和动内摩擦角均有所减小，其中当振动次数为20，EPS颗粒含量由1.4 g/kg增大到20.1 g/kg时，动黏聚力减少43.39%，动内摩擦角减少并趋于0。当EPS颗粒用量一定时，随着水泥用量的增大，EPS颗粒混合轻量土的动黏聚力和动内摩擦角均呈增大趋势，其中当振动次数为20，水泥用量由100 g/kg增大到200 g/kg时，动黏聚力增大了54.07%，动内摩擦角增大了140.95%。【结论】水泥用量和EPS颗粒用量对EPS颗粒混合轻量土的动强度参数均有较大的影响，振动次数对动黏聚力影响较大而对动内摩擦角影响甚微，在分析土体稳定性时应充分考虑以上因素的影响。 |
| 关键词: 轻量土 EPS颗粒 动黏聚力 动内摩擦角 振动次数 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目（51509211）；陕西省社会发展科技攻关项目（2015SF260）；杨凌示范区科技计划项目（2016GY-01）；西北农林科技大学国际科技合作基金项目（A213021602,A213021803）；中国博士后基金项目（2016M602863）；陕西省博士后基金项目（2018） |
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| Dynamic strength parameters of light weight soil mixed with EPS beads |
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DONG Li,HOU Tianshun,LUO Yasheng
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| Abstract: |
| 【Objective】The influence of cement content,expanded polystyrene (EPS) content and cyclic number on dynamic strength parameters of light weight soil mixed with EPS beads was studied to provide reference for using EPS beads in geotechnical engineering.【Method】The dynamic triaxial test was conducted using the loess as raw soil.The mixed light weight soil was prepared with EPS beads contents of 1.4,3.1,5.4,8.6,13.1,20.1 g/kg and cement contents of 100,150,200 g/kg.The confining pressures were set to 50,100,150 and 200 kPa,the consolidation stress ratio (Kc) was 1.0,the cyclic numbers were 10，20，30，40，50，60，70，80，90 and 100, and 5.0% compressive strain was chosen as the failure criterion.The total stress parameters of soil were calculated by Mohr’s Circle and the influencing factors were analyzed.【Result】When the consolidation stress ratio was 1.0,the dynamic strength envelopes of light weight soil mixed with EPS beads under different ratios did not pass through the origin and had intercepts at the shear stress axis.When the cement content was constant,the dynamic cohesion and dynamic internal friction angle decreased with the increase of EPS content.When the cyclic number was 20,the EPS content increased from 1.4 g/kg to 20.1 g/kg,the dynamic cohesion decreased by 43.39% and the dynamic internal friction angle decreased to 0.When EPS content was constant,with the increase of cement content,the dynamic cohesion and dynamic internal friction angle improved. With the cyclic number of 20,the cement content increased from 100 g/kg to 200 g/kg,the dynamic cohesion increased by 54.07%,and the dynamic internal friction angle increased by 140.95%.【Conclusion】Both the cement content and EPS content had great influence on the dynamic strength parameters of light weight soil mixed with EPS beads.The cyclic number had large effect on the dynamic cohesion but insignificant effect on the dynamic friction angle.In the analysis of soil stability,above factors should be fully considered. |
| Key words: light weight soil EPS beads dynamic cohesion dynamic friction angle cyclic number |
