循环荷载下牡蛎壳粉改性膨胀土累积应变规律  

Cumulative Strain Law of Expansive Soil Reinforced with Oyster Shell Powder under Cyclic Loading

作　　者：陈川 唐正辉 黄震 周维政 邵羽 贡斌 CHEN Chuan;TANG Zheng-hui;HUANG Zhen;ZHOU Wei-zheng;SHAO Yu;GONG Bin(Guangxi Communications Design Group Co.,Ltd.,Nanning 530029,China;School of Civil and Architectural Engineering,Guangxi University,Nanning 530004,China)

机构地区：[1]广西交通设计集团有限公司,南宁530029 [2]广西大学土木建筑工程学院,南宁530004

出　　处：《长江科学院院报》2025年第3期125-132,共8页Journal of Changjiang River Scientific Research Institute

基　　金：广西重点研发计划项目(桂科AB22080061);广西科技计划项目(桂科AD23026266);广西交通运输行业重点科技项目(GXJT-2020-02-08)。

摘　　要：为探究循环荷载下牡蛎壳粉改性膨胀土的累积应变和累积孔压发展规律,采用动三轴试验系统对膨胀土施加循环荷载以模拟车辆动力作用。试验涉及不同牡蛎壳粉粒径(d_(osp))、掺量(F_(osp))和循环应力比(CSR)条件下的轴向累积应变和累积孔压发展规律。研究结果表明:当d_(osp)<0.5 mm时,改性土的轴向累积应变和累积孔压随牡蛎壳粉掺量的增加而明显改善;当F_(osp)=9%、d_(osp)<0.5 mm时,改性土的动力性能较为接近;当d_(osp)>0.5 mm时,改性土的动力性能指标相比于素土有所劣化,且这种劣化作用随着牡蛎壳粉掺量的增加和粒径的增大而更加显著。根据研究结果,当牡蛎壳粉改性土用作设计速度200 km/h以下的有砟轨道铁路路基填料时,建议控制牡蛎壳粉掺量为F_(osp)=9%,粒径控制在d_(osp)=(0.25,0.5]mm范围内。This study investigates the development of cumulative strain and cumulative pore pressure of expansive soil reinforced with oyster shell powder(OSP)under cyclic loading.A GDS dynamic triaxial test system was employed to simulate vehicle dynamic actions on the soil.The experiment examines axial cumulative strain and cumulative pore pressure under particle size(d_(osp)),dosage(F_(osp)),and cyclic stress ratio(CSR).Findings reveal that for particle sizes d_(osp)<0.5 mm,both axial cumulative strain and cumulative pore pressure in the modified soil significantly improve with increasing OSP content.However,when F_(osp)=9% and d_(osp)=0.5 mm,the dynamic performance of the modified soil is relatively stable.Conversely,for particle sizes d_(osp)>0.5 mm,the dynamic performance of the modified soil deteriorates compared to plain soil,with this degradation becoming more pronounced as both OSP content and particle size increase.Based on these results,if OSP-modified soil is used as roadbed filler for ballasted track railways with design speeds below 200 km/h,it is recommended to control the OSP content at F_(osp)=9%,with particle sizes limited to the range of(0.25,0.5]mm to maintain optimal dynamic performance.

关 键 词：膨胀土 牡蛎壳粉 列车循环荷载 累计应变 孔压 

分 类 号：U416[交通运输工程—道路与铁道工程]