{"title":"湿润、干燥和加载时压实黄土的小应变刚度:实验和模型解释","authors":"","doi":"10.1016/j.trgeo.2024.101341","DOIUrl":null,"url":null,"abstract":"<div><p>Stiffness of soil at very small strains <em>G</em><sub>0</sub> is mainly affected by void ratio, effective stress and suction. Empirical equations considering those factors have been proposed to estimate <em>G</em><sub>0</sub>. However, for collapsible soil like loess, variations in suction might induce changes in void ratio of soil. The combined effect of these two factors poses challenges in accurately estimating of <em>G</em><sub>0</sub>. This paper first presents an experimental study on the <em>G</em><sub>0</sub> of collapsible loess under various conditions, including as-compacted states, wetting/drying and K<sub>0</sub> loading. <em>G</em><sub>0</sub> is estimated from shear wave velocity obtained with bender element technique. The changes of <em>G</em><sub>0</sub> with respect to void ratio, suction, effective stress, and wetting under K<sub>0</sub> stress conditions are evaluated. Test results reveal that power relationships can be defined between <em>G</em><sub>0</sub> and void ratio, suction and effective stress, respectively. The changes in <em>G</em><sub>0</sub> along wetting/drying shows an “S” shape due to the different dominant effects on soil structure, as well as the induced non-uniform volume changes when suction change at different zones. Under K<sub>0</sub> loading, <em>G</em><sub>0</sub> decreases upon wetting at stresses below the compaction stress, while it increases upon wetting at stresses above the compaction stress, due to the combined effects of densification caused by volume collapse during wetting and softening induced by suction decrease. Finally, a <em>G</em><sub>0</sub> model considering net stress and suction as independent stress variable is proposed. This model could effectively capture the change of <em>G</em><sub>0</sub> during wetting, drying and loading, as well as upon wetting under K<sub>0</sub> loading for collapsible loess.</p></div>","PeriodicalId":56013,"journal":{"name":"Transportation Geotechnics","volume":null,"pages":null},"PeriodicalIF":4.9000,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Small-strain stiffness of compacted loess upon wetting, drying and loading: Experiments and model interpretation\",\"authors\":\"\",\"doi\":\"10.1016/j.trgeo.2024.101341\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Stiffness of soil at very small strains <em>G</em><sub>0</sub> is mainly affected by void ratio, effective stress and suction. Empirical equations considering those factors have been proposed to estimate <em>G</em><sub>0</sub>. However, for collapsible soil like loess, variations in suction might induce changes in void ratio of soil. The combined effect of these two factors poses challenges in accurately estimating of <em>G</em><sub>0</sub>. This paper first presents an experimental study on the <em>G</em><sub>0</sub> of collapsible loess under various conditions, including as-compacted states, wetting/drying and K<sub>0</sub> loading. <em>G</em><sub>0</sub> is estimated from shear wave velocity obtained with bender element technique. The changes of <em>G</em><sub>0</sub> with respect to void ratio, suction, effective stress, and wetting under K<sub>0</sub> stress conditions are evaluated. Test results reveal that power relationships can be defined between <em>G</em><sub>0</sub> and void ratio, suction and effective stress, respectively. The changes in <em>G</em><sub>0</sub> along wetting/drying shows an “S” shape due to the different dominant effects on soil structure, as well as the induced non-uniform volume changes when suction change at different zones. Under K<sub>0</sub> loading, <em>G</em><sub>0</sub> decreases upon wetting at stresses below the compaction stress, while it increases upon wetting at stresses above the compaction stress, due to the combined effects of densification caused by volume collapse during wetting and softening induced by suction decrease. Finally, a <em>G</em><sub>0</sub> model considering net stress and suction as independent stress variable is proposed. This model could effectively capture the change of <em>G</em><sub>0</sub> during wetting, drying and loading, as well as upon wetting under K<sub>0</sub> loading for collapsible loess.</p></div>\",\"PeriodicalId\":56013,\"journal\":{\"name\":\"Transportation Geotechnics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.9000,\"publicationDate\":\"2024-09-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Transportation Geotechnics\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2214391224001624\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, CIVIL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Transportation Geotechnics","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2214391224001624","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CIVIL","Score":null,"Total":0}
Small-strain stiffness of compacted loess upon wetting, drying and loading: Experiments and model interpretation
Stiffness of soil at very small strains G0 is mainly affected by void ratio, effective stress and suction. Empirical equations considering those factors have been proposed to estimate G0. However, for collapsible soil like loess, variations in suction might induce changes in void ratio of soil. The combined effect of these two factors poses challenges in accurately estimating of G0. This paper first presents an experimental study on the G0 of collapsible loess under various conditions, including as-compacted states, wetting/drying and K0 loading. G0 is estimated from shear wave velocity obtained with bender element technique. The changes of G0 with respect to void ratio, suction, effective stress, and wetting under K0 stress conditions are evaluated. Test results reveal that power relationships can be defined between G0 and void ratio, suction and effective stress, respectively. The changes in G0 along wetting/drying shows an “S” shape due to the different dominant effects on soil structure, as well as the induced non-uniform volume changes when suction change at different zones. Under K0 loading, G0 decreases upon wetting at stresses below the compaction stress, while it increases upon wetting at stresses above the compaction stress, due to the combined effects of densification caused by volume collapse during wetting and softening induced by suction decrease. Finally, a G0 model considering net stress and suction as independent stress variable is proposed. This model could effectively capture the change of G0 during wetting, drying and loading, as well as upon wetting under K0 loading for collapsible loess.
期刊介绍:
Transportation Geotechnics is a journal dedicated to publishing high-quality, theoretical, and applied papers that cover all facets of geotechnics for transportation infrastructure such as roads, highways, railways, underground railways, airfields, and waterways. The journal places a special emphasis on case studies that present original work relevant to the sustainable construction of transportation infrastructure. The scope of topics it addresses includes the geotechnical properties of geomaterials for sustainable and rational design and construction, the behavior of compacted and stabilized geomaterials, the use of geosynthetics and reinforcement in constructed layers and interlayers, ground improvement and slope stability for transportation infrastructures, compaction technology and management, maintenance technology, the impact of climate, embankments for highways and high-speed trains, transition zones, dredging, underwater geotechnics for infrastructure purposes, and the modeling of multi-layered structures and supporting ground under dynamic and repeated loads.