<p><p><h2>Preferred Design Procedure</h2>There are two preferred partial encapsulation design procedures based on the rational principles and another two design procedures based on empirical evidence. The design procedure described in the FHWA <em>Geotechnical Aspects of Pavements</em> (Christopher et. al. 2006, revised 2010) is a mechanistic-empirical design procedure while the other three design procedures are based on a limited number of successful case histories.</p><p>The design method explained by the Picornell-Darder (1985) determines the depth of vertical moisture barrier based on the climatic conditions. On the other hand, the design method described by Lord and Koerner (1986) determines the water diffusion through membrane based on the diffusion coefficient of soil. Moreover, different construction methods are included in Steinberg (1998) for the membrane installation in the expansive soil.</p><p>The FHWA Geotechnical Aspects of Pavements (Christopher et al. 2006, revised 2010) contains the mechanistic-empirical design method for partial encapsulation. The design method is based on the use of partial encapsulation to maintain the resilient modulus of subgrade over the service life of the pavement. The document is summarized below.</p><p><table class='tablepress' id='tablepress-309'><thead><th><center>Publication Title</th><th><center>Publication
Year
</th><th><center>Publication Number</th><th><center>Available for Download</th></thead><tbody><tr><td >Geotechnical Aspects of Pavement </td><td ><center>2006, revised 2010</td><td ><center>FHWA NHI-05-037
FHWA NHI-10-092
</td><td ><center>No for 2010
<center>Yes for 2006<sup>1</td></tr></tbody></table><br><p class="disclaimer">¹ <a href="http://www.nhi.fhwa.dot.gov/training/nhistore.aspx">http://www.nhi.fhwa…;