Geotextiles used to reinforce soft soil foundations

Detert, H. Hangen, A.A. Lavasan Huesker Synthetic GmbH, Gescher, Germany 

With the development of geosynthetics, great achievements have been made in improving foundation soils. As a result of this, nearly all functions of geosynthetics can be used reinforcement, separation, filtration, and drainage. 

The following sections provide a basic overview on modeling, design, and the corresponding requirements for geosynthetic reinforcement, with an emphasis on basal-reinforced embankments, geotextile-encased columns (GECs), and pded embankments. 

Geotextiles. http //dx.doi.org/10.1016/B978-0-08-100221-6.00016-4 Copyright 2016 Elsevier Ltd. All rights reserved. 

Basal reinforcement mainly (1) increases the stability of the embankment by mobilizing the force in the reinforcement, (2) confines the fill material and forms a flexible foundation (ductile failure in contrast to rapid failure of unreinforced embankment), (3) handles infiltration and separation of the subgrade into fill material, and (4) makes the settlement of embankments more uniform. 

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Geotextiles used to reinforce soft soil foundations... 

The use of geotextiles to reinforce soft foundation soils has progressed from the earliest applications some 40 years ago to the current status of widespread use and success. This chapter presents three major application areas (1) basal reinforcement, (2) geotextile-encased granular columns, and (3) geosynthetic piled foundations. In addition to the descriptions, elements of design, and information on performance, a specific project example was given for each topic. Further advances can and should be made, but we beheve that the current state of the practice in the selected applications is properly reflected here. 

One technique to improve the stability of breakwaters and containment dykes con-stmcted on soft foundations is to use geotextile reinforcement across the base of the stmcture (Fig. 20.19). This basal reinforcement technique has been used successfully for many years in the onshore construction of embankments on soft foundation soils, and is discussed in detail in chapter Geotextiles used in reinforcing foundations. Because of its cost—benefits, this technique has also been used in marine engineering structures over the past 20 years. 

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