路基台背回填施工中气泡混合轻质土的应用研究  

Research on Application of Bubble Mix Light Soil in Subgrade Abutment Backfilling Construction

作　　者：邱雨生 Qiu Yusheng(China Highway Engineering Consulting Group Co.,Ltd.,Beijing 100089,China)

机构地区：[1]中国公路工程咨询集团有限公司,北京市100089

出　　处：《北方交通》2021年第9期32-36,共5页Northern Communications

摘　　要：为防止台背路基与桥台结构物产生不均匀沉降,选用气泡混合轻质土填筑台背路基,通过室内试验进行气泡混合轻质土配合比设计,并结合试验段对台背轻质土路基应用效果进行评价。结果表明,轻质土湿密度较小,同龄期的体积吸水率相对较大、无侧限抗压强度相对较小;高岭土掺量增加10%,轻质土体积吸水率约至少提高4.5%、同龄期抗压强度降低4.8%以上;养生前28d抗压强度增长较显著,28d抗压强度约为90d抗压强度的81.3%;台背施工中填筑轻质土路床及路床以下轻质土7d无侧限抗压强度满足路基强度设计要求且水稳性能良好;台背轻质土填筑280d后,路基累计沉降量趋于稳定,约为0.80mm,小于设计规范中路桥过渡段沉降标准。In order to prevent uneven settlement between abutment subgrade and abutment structures,bubble mix light soil is selected to fill the abutment subgrade.The design of mix proportion of bubble mix light soil is performed through indoor test,and the application effect of light soil subgrade of abutment is evaluated in combination with the test section.The results show that,the wet density of lightsoil is small,the volumetric water absorption is relatively large and the unconfined compressive strength is relatively small at the same age;with the increase of kaolin content by 10%,the volumetric water absorption of lightsoil increases by at least 4.5%,and the compressive strength decreases by more than 4.8%at the same age;the 28d compressive strength increases significantly before curing,and the 28d compressive strength is about 81.3%of the 90d compressive strength;during the abutment construction,the light soil roadbed and the light soil below the roadbed are filled with 7d unconfined compressive strength,which meets the design requirements of subgrade strength with good water stability performance;after the light soil of abutment is filled with 280d,the cumulative settlement of subgrade tends to be stable,about 0.80mm,which is less than the settlement standard of road and bridge transition section in the design specification.

关 键 词：台背路基 气泡混合轻质土 配合比 应用研究 

分 类 号：U416.1[交通运输工程—道路与铁道工程]