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Figure 6. Free shrinkage curves of Héricourt clayey soil (PI=37) than 50% shrinkage). Once treated with 5% quicklime, w, is displaced towards higher water content (w,=55%), well above the OPN conditions, ensuring the volume stability of the material.

Figure 6 Free shrinkage curves of Héricourt clayey soil (PI=37) than 50% shrinkage). Once treated with 5% quicklime, w, is displaced towards higher water content (w,=55%), well above the OPN conditions, ensuring the volume stability of the material.

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Several evaluations of the results have been performed, no new slips, slides or sloughs have occurred. The viability and economical benefits of the solution were obvious. A recent visit (Figure 1) showed that the sheepfoot roller imprint was still visible both above and below the water surface, 35 years after the job (Herrier and al. 2012). The picture was taken during a maintenance phase, when the water level was below the normal one, one can see minor erosion along the water level, due to departure of small rocks or “untreated clay balls”, not mixed efficiently with lime due to the poor mixing quality at these ages. The maintenance operations are very limited on this section, considering the lime-treated part is durable and is significantly cost-saving. Figure 1. Lime-treated section of the Friant-Kern Canal (taken in November 2010) on the left part; the right part consist of original, untreated slope covered with gravel.
Several evaluations of the results have been performed, no new slips, slides or sloughs have occurred. The viability and economical benefits of the solution were obvious. A recent visit (Figure 1) showed that the sheepfoot roller imprint was still visible both above and below the water surface, 35 years after the job (Herrier and al. 2012). The picture was taken during a maintenance phase, when the water level was below the normal one, one can see minor erosion along the water level, due to departure of small rocks or “untreated clay balls”, not mixed efficiently with lime due to the poor mixing quality at these ages. The maintenance operations are very limited on this section, considering the lime-treated part is durable and is significantly cost-saving. Figure 1. Lime-treated section of the Friant-Kern Canal (taken in November 2010) on the left part; the right part consist of original, untreated slope covered with gravel.
Figure 2. Kneading compaction tool (a) and permeameter (b).
Figure 2. Kneading compaction tool (a) and permeameter (b).
The k values remained constante with time, indicating that the final permeability was already obtained after 1 month (curing done with constant water content). As a result, the preferred conditions for reaching low permeability values of the lime-treated silty soil (2 to 3% lime) are: (i) high moisture content and (ii) kneading compaction. These results were further explained by mercury intrusion porosimetry which highlighted the changes in the poral structure of treated soils. The biggest pores (>3ym), and intermediate-sized (between 3000A and 3m) are considered as responsible for the water path. W hen treated with lime, a third class of smaller pore appeared (<3000 A). After lime-treatment in the humid state and kneading compaction, the amount of pores >3pm was strongly reduced in favour of the smallest pore size (Figure 3), that is in favour of very small pores that do not affect the permeability. As a conclusion, the placement method is far more important than final density in the control of permeability. Figure 3. Mercury intrusion porosimetry of untreated (red curve) and lime-treated (blue curve) samples, as a function of water content and compaction procedure (silty soil from Moulin de Laffaux, France, PI=12.7).
The k values remained constante with time, indicating that the final permeability was already obtained after 1 month (curing done with constant water content). As a result, the preferred conditions for reaching low permeability values of the lime-treated silty soil (2 to 3% lime) are: (i) high moisture content and (ii) kneading compaction. These results were further explained by mercury intrusion porosimetry which highlighted the changes in the poral structure of treated soils. The biggest pores (>3ym), and intermediate-sized (between 3000A and 3m) are considered as responsible for the water path. W hen treated with lime, a third class of smaller pore appeared (<3000 A). After lime-treatment in the humid state and kneading compaction, the amount of pores >3pm was strongly reduced in favour of the smallest pore size (Figure 3), that is in favour of very small pores that do not affect the permeability. As a conclusion, the placement method is far more important than final density in the control of permeability. Figure 3. Mercury intrusion porosimetry of untreated (red curve) and lime-treated (blue curve) samples, as a function of water content and compaction procedure (silty soil from Moulin de Laffaux, France, PI=12.7).
Figure 4. Isotropic compression of untreated and lime-treated silty soil from Moulin de Laffaux, PI=12.7 (6 month curing). quicklime treatment (dosage corresponding to the lime fixation point). This soil had the following characteristics: 94% particles <80ym, 75% <2um, Wp=35%, Wy =72%, PI=37, Wopy=27.5%, Qy-1.45g/em?. Several observations were made: the swelling index was divided by 5 to 10 times after treatment (C, between 0.005 and 0.010), the yield resistance (p’,) was also multiplied by a factor 5 to 10 (p’, values between 490 and 660 kPa for the treated specimen). The compressibility indexes were similar for the two series.
Figure 4. Isotropic compression of untreated and lime-treated silty soil from Moulin de Laffaux, PI=12.7 (6 month curing). quicklime treatment (dosage corresponding to the lime fixation point). This soil had the following characteristics: 94% particles <80ym, 75% <2um, Wp=35%, Wy =72%, PI=37, Wopy=27.5%, Qy-1.45g/em?. Several observations were made: the swelling index was divided by 5 to 10 times after treatment (C, between 0.005 and 0.010), the yield resistance (p’,) was also multiplied by a factor 5 to 10 (p’, values between 490 and 660 kPa for the treated specimen). The compressibility indexes were similar for the two series.
alumina species from clays and water, giving a material that is almost not compressible, and not subjected to deformations if submitted to stresses until several hundred kPa. Figure 5. Evolution of the shear resistance parameters with time (treated silt from Soumagne,Belgium, PI=16). The white points at t=0 are related to the untreated specimen.
alumina species from clays and water, giving a material that is almost not compressible, and not subjected to deformations if submitted to stresses until several hundred kPa. Figure 5. Evolution of the shear resistance parameters with time (treated silt from Soumagne,Belgium, PI=16). The white points at t=0 are related to the untreated specimen.
TEE. ELVolull LGoOLolallut Bot (by h internal (by Hole Erosion Test HET) and external Mobile Jets Erosion Test, MoJET) erosion resistance were studied, in order to evaluate the impact of lime trea was tment on the critical parameters of the materials. HET performed at Cemagref (France) on a clayey silt taken from a Camargue Dike (France): 95% particles <80 um, 30% <2um, PI=11. The erosion rates vs tangential stress are reported in Figure 7 for untreated specimen, and 2% lime-treated after 3 curing periods. Figure 7. Hole Erosion Test: erosion rate vs tangential stress for untreated and 2% lime-treated clayey silt from a Camargue dike (PI= 11).
TEE. ELVolull LGoOLolallut Bot (by h internal (by Hole Erosion Test HET) and external Mobile Jets Erosion Test, MoJET) erosion resistance were studied, in order to evaluate the impact of lime trea was tment on the critical parameters of the materials. HET performed at Cemagref (France) on a clayey silt taken from a Camargue Dike (France): 95% particles <80 um, 30% <2um, PI=11. The erosion rates vs tangential stress are reported in Figure 7 for untreated specimen, and 2% lime-treated after 3 curing periods. Figure 7. Hole Erosion Test: erosion rate vs tangential stress for untreated and 2% lime-treated clayey silt from a Camargue dike (PI= 11).
Figure 8. Hole Erosion Test: erosion rate vs water velocity for untreated and 2% lime-treated clayey silt from a Camargue dike (PI= 11).
Figure 8. Hole Erosion Test: erosion rate vs water velocity for untreated and 2% lime-treated clayey silt from a Camargue dike (PI= 11).
Figure 9. Mobile treatment plant used for the construction of an experimental dyke in Rouen (France) 5.2. Present applications (US case)
Figure 9. Mobile treatment plant used for the construction of an experimental dyke in Rouen (France) 5.2. Present applications (US case)
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