基于真空固结仪的软土次固结沉降特性研究  

Study on Settlement Characteristics of Secondary Consolidation of Soft Soil Based on Vacuum Consolidator

作　　者：宋宝禄 SONG Baolu(China Railway 16th Bureau Group Electrification Engineering Co.Ltd.,Beijing 100018,China)

机构地区：[1]中铁十六局集团电气化工程有限公司,北京100018

出　　处：《铁道建筑技术》2024年第7期49-53,共5页Railway Construction Technology

基　　金：中铁十六局集团有限公司科技研究开发计划项目(K2022-21B)。

摘　　要：对于软土次固结的研究多采用室内试验的方式进行,但是目前较难实现直接得到土体突变全过程的曲线。本文基于改进的真空固结仪,进行了室内一维蠕变试验,研究了在正负压联合作用下的软土次固结沉降特性。研究发现:加载阶段,随着超载比的增大,变形增大,孔隙比减小;再加载主固结阶段,主固结变形会随着负压力增大而减小;根据次固结系数与超载比的关系,拟合了可用于计算某一超载比下的联合预压再加载阶段次固结系数的计算公式,可为软土真空-堆载联合预压的设计、施工提供参考。The majority of research on secondary consolidation of soft soil is conducted through indoor tests,which present certain limitations in terms of directly observing the entire process of soil sudden change.In this paper,an indoor one⁃dimensional creep test was conducted using an improved vacuum consolidator to investigate the settlement characteristics of secondary consolidation of soft soil under the combined effect of positive and negative pressure.It was found that,during the loading stage,the deformation increases and the pore ratio decreases with the increase of the overload ratio.During the reloading stage of primary consolidation,the primary consolidation deformation decreases with the increase of negative pressure.Based on the relationship between the secondary consolidation coefficient and the surcharge ratio,a formula for calculating the secondary consolidation coefficient during the combined preloading and reloading stage under a certain surcharge ratio has been fitted,which can provide a reference for the design and construction of vacuum⁃surcharge combined preloading for soft soil.

关 键 词：次固结 正负压联合 沉降特性 软土 真空固结仪 

分 类 号：TU41[建筑科学—岩土工程] TU472.33[建筑科学—土工工程]