<p><p><strong>References:<br></strong><em>Schaefer et al. (2016)</em></p><p><strong>Method Summary</strong></p><p>Calculating the displacement ratio, D<sub>R</sub>, is a method of evaluating the stability of sites where a fill preload is utilized. The displacement ratio is measured along and transverse to the perimeter of the fill.
<p><p><strong>References:<br></strong><em>Yan and Chu (2003a, b)</em></p><p><strong>Method Summarys </strong></p><p>Field vane shear tests are performed in the field in order to determine the in-situ shear strength of the soil.
<p><p><strong>References:<br></strong><em>Schaefer et al.
<p><p><strong>References:<br></strong><em>Schaefer et al. (2016)<br>Holtz (1987)</em></p><p><strong>Method Summary</strong></p><p>Records should be kept of equipment inspections, PVD material quality, PVD dimensions (width and thickness), mandrel dimensions, mandrel type, PVD installation depth, spacing, PVD location, verticality of installed PVDs, drainage blanket material and placement conditions, and fill material and placement in order to verify adherence to design.
<p><p><strong>References:<br></strong><em>Chu and Choa (1995)<br>Chu et al. (2004)</em></p><p><strong>Method Summary</strong></p><p>Tests on PVDs are used to obtain information on the filter quality, discharge capacity, and tensile strength. For PVDs with an apparent opening size (AOS) greater than 40 μm, ASTM D4751 can be used to determine the AOS of the PVD. The permeability of the PVD can be determined in accordance with ASTM D4491. ASTM D4632 is often specified to measure tensile strength of the PVD.
Current FHWA Reference(s):
Schaefer et al. (2016)
Rixner et al. (1986).
Supporting Reference(s):
Arulrajah et al. (2004)
Bergado and Patawaran (2000)
Chu et al. (2002a)
Chu et al. (2004)
Hansbo (1979)
Hansbo (1986)
Hansbo (2004)
Holtz et al. (1991)
Indraratna et al. (2007)
Lin et al. (2006)
Wang and Jiao (2004)
Welsh (1987)
<p><p><strong>References:<br></strong><em>Schaefer et al. (2016)<br>Hansbo (2004)<br>Holtz (1987)<br>SHRP 2 Phase I Technology Assessment (2008)<br>Welsh (1987)</em></p><p><strong>Method Summary</strong></p><p>Piezometers are used to measure and monitor pore water pressures before, during, and after preloading. Once installed, the piezometer should be read on a regular schedule. Piezometers provide a good indication of the degree of consolidation.