Monday, December 10, 2012



Results of a limited number of model tests conducted in the early to mid-1980's to determine the bearing capacity of surface foundations (that is, Df =0) resting on geotextile-reinforced soils can be found in the literature. Guido et al. [4] reported results of several laboratory model tests for a square surface foundation measuring 0.31 m × 0.31 m (B × B) and supported by a loose to medium sand reinforced with multiple layers of nonwoven melt-bonded geotextile (size b ×b). Figure 7.13 shows the geometric parameters of  the problem under consideration, and Fig. 7.14 shows some of the results of these tests.  For the tests reported in Fig. 7.14, the following parameters apply: relative density of sand, Dr = 50%; width of geogrid layers, b = 0.62 m; b/B = 0.2; u/B = 0.5;  and h/B = 0.25.

Similar model test results on a continuous surface foundation supported by a saturated clay (Φ = 0 condition) reinforced by heat-bonded nonwoven geotextile were reported by Sakti and Das [5]. The load-settlement curves for some of these tests are given in Fig. 7.15. For these tests the following parameters apply:  width, B = 76.2 mm; undrained cohesion of clay, cu = 22.5 kN/m2, and u/B = h/B = 0.33. The tests clearly show that the ultimate bearing capacity of foundations increases when geotextile reinforcement is used.

COMMENTS ON GEOTEXTILE REINFORCEMENT Figures 7.14 and 7.15 show  that geotextile reinforcement contributes  to the increase in ultimate bearing capacity of foundations on sand and saturated clay. However, at low settlement level of the foundation, geotextile reinforcement hardly contributes to the load bearing capacity. This is...(more)

FIGURE 7.13   Foundation on geotextile-reinforced soil

FIGURE 7.14 Model test results of Guido et al. [4] on geotextile-
reinforced sand for a square surface foundation

FIGURE 7.15 Model test results of Sakti and Das [5] on geotextile-reinforced
saturated clay for a continuous surface foundation


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