Related to the above news.
One shouldn't be surprised if they can not dredge the Setu using these conventional dredgers leased from Swedish and Dutch companies. Setu's base is so hard (N Value > 30) - see my earlier post about this - that normal dredging may not succeed at all. Both NIOT and GSI had warned about this.
If someone be interested in facts and details, here is the blueprint of the present channel configuration, prepared by L&T Ramboll between 2004 and 2005. Notice the circle over the Rama Setu area - this has been zoomed in and details are shown in 'X'.
<img src='http://www.archive.org/download/SSCP_Vibro_Coring_Locations/MapofNIOTVibroCores.jpg' border='0' alt='user posted image' />
Do notice the zoom area marked as "DETAIL - X", which shows the four bore hole test locations that were done to ascertain how to dredge the Setu area. (Minister is lying when he says NIOT did these boreholes to assess whether there is a man-made structure. The Testing was done purely to ascertain how to dredge this. No speculation needed, one may just read the NIOT report. Here is the link to Bore Log data from L&T.
So, anyways, the hardness recorded on all the 4 boreholes in the area are fairly high (N > 30) which means the rocks are absolutely hard.
This is why D.N.Seshagiri, (Former) Director of Geological Survey of India wrote in his assessment, that:
<!--QuoteBegin-->QUOTE<!--QuoteEBegin-->Attention is drawn not only to the zones wherein rock has been encountered but also to those that have recorded high N values.
An empirical relationship between N value and uncon. Comp strength (ton/ft2) has been established.
N value Uncon. Comp. Strength (T/ft2) Consistency
8-15 1.0-2.0 Stiff
15-30 2.0-4.0 Very Stiff
Over 30 Over 4.0 Hard
(Ref. Soil Mechanics and Foundations. J.V.Parcher & R.E.Means. Printice-Hall of India 1974)
This has been corroborated by the Earth Manual (U.S. Dept. of Interior. Water & Power resource service. II Edn.) as follows:
Blows per foot Consistency
Below 2 Very soft
2 to 4 Soft
4 to 8 Medium
8 to 15 Firm
15 to 30 Very firm
Above 30 Hard
In view of the above, the amenability to conventional dredging of not only the rocky strata but also of the softer sediments with high N value is a suspect.
<span style='font-size:14pt;line-height:100%'>Other methods of removal have to be resorted to.</span>
<!--QuoteEnd--><!--QuoteEEnd-->
Which are those "other methods"? The most common and "convenient" one, is to use explosives, and with repeated shock explosions, to blow up the hard strata.
So what next? Let us watch as Baalu collabrates with Talibans and bring their expertise on how they blew up Bamiyan Buddhas, and blow up the Setu. (Afzal Guru is still alive - use his expertise)
One shouldn't be surprised if they can not dredge the Setu using these conventional dredgers leased from Swedish and Dutch companies. Setu's base is so hard (N Value > 30) - see my earlier post about this - that normal dredging may not succeed at all. Both NIOT and GSI had warned about this.
If someone be interested in facts and details, here is the blueprint of the present channel configuration, prepared by L&T Ramboll between 2004 and 2005. Notice the circle over the Rama Setu area - this has been zoomed in and details are shown in 'X'.
<img src='http://www.archive.org/download/SSCP_Vibro_Coring_Locations/MapofNIOTVibroCores.jpg' border='0' alt='user posted image' />
Do notice the zoom area marked as "DETAIL - X", which shows the four bore hole test locations that were done to ascertain how to dredge the Setu area. (Minister is lying when he says NIOT did these boreholes to assess whether there is a man-made structure. The Testing was done purely to ascertain how to dredge this. No speculation needed, one may just read the NIOT report. Here is the link to Bore Log data from L&T.
So, anyways, the hardness recorded on all the 4 boreholes in the area are fairly high (N > 30) which means the rocks are absolutely hard.
This is why D.N.Seshagiri, (Former) Director of Geological Survey of India wrote in his assessment, that:
<!--QuoteBegin-->QUOTE<!--QuoteEBegin-->Attention is drawn not only to the zones wherein rock has been encountered but also to those that have recorded high N values.
An empirical relationship between N value and uncon. Comp strength (ton/ft2) has been established.
N value Uncon. Comp. Strength (T/ft2) Consistency
8-15 1.0-2.0 Stiff
15-30 2.0-4.0 Very Stiff
Over 30 Over 4.0 Hard
(Ref. Soil Mechanics and Foundations. J.V.Parcher & R.E.Means. Printice-Hall of India 1974)
This has been corroborated by the Earth Manual (U.S. Dept. of Interior. Water & Power resource service. II Edn.) as follows:
Blows per foot Consistency
Below 2 Very soft
2 to 4 Soft
4 to 8 Medium
8 to 15 Firm
15 to 30 Very firm
Above 30 Hard
In view of the above, the amenability to conventional dredging of not only the rocky strata but also of the softer sediments with high N value is a suspect.
<span style='font-size:14pt;line-height:100%'>Other methods of removal have to be resorted to.</span>
<!--QuoteEnd--><!--QuoteEEnd-->
Which are those "other methods"? The most common and "convenient" one, is to use explosives, and with repeated shock explosions, to blow up the hard strata.
So what next? Let us watch as Baalu collabrates with Talibans and bring their expertise on how they blew up Bamiyan Buddhas, and blow up the Setu. (Afzal Guru is still alive - use his expertise)