饱和重塑黏性土固结过程的孔径分布特性研究  

Study on Pore Size Distribution Characteristics of Saturated Remolded Clay during Consolidation

作　　者：郑娟 伍肖 赖秀英 Zheng Juan;Wu Xiao;Lai Xiuying(College of Civil Engineering,Putian University,Putian,Fujian 351100,P.R.China;Fujian University Engineering Research Center for Disaster Prevention and Mitigation of Southeast Coastal Engineering Structures,Putian,Fujian 351100,P.R.China;Taizhou Traffic Survey and Design Institute,Taizhou,Zhejiang 318000,P.R.China)

机构地区：[1]莆田学院土木工程学院,福建莆田351100 [2]东南沿海工程结构防灾减灾福建省高校工程研究中心,福建莆田351100 [3]台州市交通勘察设计院,浙江台州318000

出　　处：《地下空间与工程学报》2023年第1期141-147,共7页Chinese Journal of Underground Space and Engineering

基　　金：福建省自然基金面上项目(2020J01910);福建省自然基金青年项目(2020J05208)。

摘　　要：对饱和重塑黏性土采用不同加载速率进行排水固结,将不同加载时段的试样进行核磁共振(NMR)测量,分析横向驰豫时间T2分布、T2谱面积变化与孔隙的关系,研究饱和重塑黏性土固结过程的孔径分布特性。结果表明:饱和重塑黏性土试样初始阶段的横向驰豫时间T2为两谱峰,分别代表大小孔径的孔隙,随着加载的进行,各试样组试样孔径逐渐向较小尺寸转移,最终变成致密均匀的小孔径孔隙;恒载一定时间后,孔径变化不再明显,说明孔隙中可流动流体已排尽,此时完成排水固结;根据加载速率与最大孔压的正相关关系得到一分界速率,合理推断控制加载速率小于该值,则主固结阶段即完成排水固结。The saturated remolded clay was drained and consolidated at different loading rates,and the samples in different loading periods were measured by nuclear magnetic resonance(NMR).The relationship between transverse relaxation time T2 distribution,T2 spectral area change,and the porosity was analyzed;furthermore,the pore size distribution characteristics of saturated remolded clay during consolidation were studied.The results show that the transverse relaxation time T2 of saturated remolded cohesive soil samples in the initial stage is two spectral peaks,representing the pores with large and small pore sizes,respectively.With the progress of loading,the pore size of each sample group gradually shifts to smaller sizes and finally becomes dense and uniform pores with small pore sizes.After a specific time of dead load,the change in pore diameter is no longer noticeable,indicating that the flowable fluid in the pore has been drained,and the drainage consolidation is completed at this time.A boundary rate is obtained according to the positive correlation between the loading rate and the maximum pore water pressure.If the controlled loading rate is less than this value,it is inferred that the drainage consolidation is completed in the main consolidation stage.

关 键 词：加载速率 饱和重塑黏性土 孔径分布 核磁共振 横向驰豫时间 

分 类 号：TU411[建筑科学—岩土工程]