| Abstract | To investigate the behavior of geotextile reinforced sand, triaxial UU, CIU
and CID compression tests we r e performed on Ayutthaya s and reinforced with
horizontal discs of nonwoven geotextiles . Two kinds of stronger and weaker
geotextiles were used, namely: Polyfelt PEC-200 and Polyfelt TS-700, with
normalized spacing 0.5, 0. 33 and 0. 25 . Samples were prepared at the same wat e r
content or dry density.
Comparison of unreinforced and reinforced soi1 specimens shows that with the
same kind of geotextile, the strength increases with increasing confining
pressure and decreasing normalizeds pacing. With the same confining pressure and
normalized s pacing , the strength increases with the increase of geotextile
stiffness . For UU test, with one , two, and three layers of TS-700 t he c/c
( cis the apparent cohesion of unreinforced samples and Cr is the apparent
cohesion of reinforced samples) values we r e 1.06 , 1. 65 and 2 . 65 a nd r/<1> (¢ is
the internal friction ang l e of unreinforced amp les and ¢r is the internal
friction ang le of reinforced samples) values we r e 1. 12 , 1.16 and 1. 21,
respectively. Similar l y , with one , two , three layers of PEC-200 , t he c/c values
we r e 1.06 , 1. 71 and 2 . 71, and¢/¢ value were 1.13 , 1.17 , and 1. 29, respectively .
For CID test, with one , two , layers of TS-700 the c / c values were 1.1 and 1. 9
and ¢/ values we r e 1.08 and 1.15 , respectively. Similarly, with one and t wo
layers of PEC- 200, the values of cr/c we re 1.1 and 2 . 0 and q> r/¢ value we re 1.11
and 1. 21, respectively.
Geotextile discs restrain the dilation of s and because of interface friction
mobilization . It is found that the geotextile- soil interface friction angle
de creases with increasing confining pressure and the mobi1ized interface friction
angle inceases with increasing shear strain. The mobilization of interface
friction is a progressive process. Furthermore, the reinforced sand samples
compacted at optimum moisture content yielded higher strength compared to wet
side and dry side compacted samples. The results also illustrate the stiffening
effect and strength increase imparted to the soi1 through the enhanced confining
effect of geotextile reinforcements . |
