制样方法对粉土室内压缩试验结果的影响研究  

Study on Effect of Sample Preparation Methods on Indoor Silt Compression Test

作　　者：周瑞荣[1] 宗明明[1] 王巧云[1] ZHOU Ruirong;ZONG Mingming;WANG Qiaoyun(College of Civil Engineering,San Jiang University,Nanjing 210012,China)

机构地区：[1]三江学院土木工程学院,南京210012

出　　处：《现代交通技术》2018年第5期1-5,45,共6页Modern Transportation Technology

摘　　要：通过开展室内单向压缩试验,研究不同制样方法下(预压法、压样法和切样法)土体压缩变形的规律,揭示不同制样方法制取的土样与原状土样进行压缩试验结果的对比规律,分析不同制样方法对土体扰动性的影响。先采用体积压缩法判别土样扰动程度,基于卡萨格兰德法确定土样的先期固结压力。发现当预压力较小时,卡萨格兰德法确定的前期固结应力要稍大于预压力;随着预压力的增加,卡萨格兰德法确定的前期固结应力与预压力基本一致。接着,对卡萨格兰德法确定的结果略加修正,便可较为精准地确定该土样的先期固结压力。预压法的压缩曲线与原状土取样室内压缩试验的曲线比较接近,并且随着预压力的增加,土样的扰动指数增大,扰动程度变高。压样法和切样法土样的压缩曲线与重塑土样的压缩曲线接近重合,表明其扰动程度很高,并处于同一扰动指数区间。By conducting the indoor unidirectional compression test, the law of soil compression deformation under differentsample preparation methods （preloading method, pressure sample method and cutting method） is studied, the comparison oftest results between original soil samples and those made by different sample preparation methods is revealed, the influence ofdifferent sample preparation methods on soil disturbance is analyzed. The volumetric compression method is used to discrimi-nate the degree of soil sample disturbance, and the pre-consolidation pressure of the soil sample is determined based on theCasa Grande method. It is found that when the pre-pressure is small, the pre-consolidation stress determined by the CasaGrande method is slightly larger than the pre-pressure; as the pre-pressure increases, the pre-consolidation stress determinedby the Casa Grande method is basically consistent with the pre-pressure. A slight correction of the results determined by theCasa Grande method can more accurately determine the pre-consolidation pressure of the soil sample. The compression curve ofthe preloading method is close to the curve of the uncompressed soil sampling indoor compression test, and as the pre-pressureincreases, the disturbance index of the soil sample increases, that is, the degree of disturbance becomes higher. The compres-sion curve of the soil sample and the sample cutting method coincide with the compression curve of the reshaped soil sample,indicating that the degree of disturbance is high and is in the same disturbance index interval.

关 键 词：压缩-回弹 固结压力 孔隙比 扰动 

分 类 号：U412.22[交通运输工程—道路与铁道工程]