{"title":"Effect of smear zone on the consolidation and strength characteristics of soil under radial drainage","authors":"R. Aparna, R. Robinson, S. R. Gandhi","doi":"10.1680/jgrim.21.00040","DOIUrl":null,"url":null,"abstract":"Vertical drains installed in soft clay deposits enhance the rate of consolidation in preloading projects. Using a mandrel to install the prefabricated vertical drains (PVD), its insertion and withdrawal will result in the remoulding of the soil zone surrounding it, called the smear zone. The extent of the smear zone is an important parameter that characterizes the smearing effect. This paper describes this effect in terms of smear ratio (i.e., the ratio of the diameter of smear zone ds to the diameter of drain, dw) on the consolidation characteristics of soil with radial drainage. A series of radial consolidation tests with a predetermined smear zone in a model unit cell was conducted by varying the diameter of the smear zone. The experimental results show that beyond a smear ratio of 4, the soil behaves as if it is in a fully remoulded condition. The results were compared with some of the theoretical approaches reported in the literature. The analytical solution that predicts the time-settlement curve in a better way is identified. Also, it is observed that the gain in undrained shear strength due to the consolidation of soft clay decreases with the increase in the diameter of the smear.","PeriodicalId":51705,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Ground Improvement","volume":null,"pages":null},"PeriodicalIF":1.3000,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of the Institution of Civil Engineers-Ground Improvement","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1680/jgrim.21.00040","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, GEOLOGICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Vertical drains installed in soft clay deposits enhance the rate of consolidation in preloading projects. Using a mandrel to install the prefabricated vertical drains (PVD), its insertion and withdrawal will result in the remoulding of the soil zone surrounding it, called the smear zone. The extent of the smear zone is an important parameter that characterizes the smearing effect. This paper describes this effect in terms of smear ratio (i.e., the ratio of the diameter of smear zone ds to the diameter of drain, dw) on the consolidation characteristics of soil with radial drainage. A series of radial consolidation tests with a predetermined smear zone in a model unit cell was conducted by varying the diameter of the smear zone. The experimental results show that beyond a smear ratio of 4, the soil behaves as if it is in a fully remoulded condition. The results were compared with some of the theoretical approaches reported in the literature. The analytical solution that predicts the time-settlement curve in a better way is identified. Also, it is observed that the gain in undrained shear strength due to the consolidation of soft clay decreases with the increase in the diameter of the smear.
期刊介绍:
Ground Improvement provides a fast-track vehicle for the dissemination of news in technological developments, feasibility studies and innovative engineering applications for all aspects of ground improvement, ground reinforcement and grouting. The journal publishes high-quality, practical papers relevant to engineers, specialist contractors and academics involved in the development, design, construction, monitoring and quality control aspects of ground improvement. It covers a wide range of civil and environmental engineering applications, including analytical advances, performance evaluations, pilot and model studies, instrumented case-histories and innovative applications of existing technology.