A history of vibratory deep compaction 25
shifts employing up to 15 vibrators simultaneously. Compaction results
were checked continually by static cone penetration tests. The settlement
performance of the structure was as expected by the soil mechanics consultants. Measurements conducted over many years after the plant was put into
operation showed only 2–3 cm of settlement even of the heaviest footings.
After India and Pakistan gained their independence in 1947, lengthy and
difficult negotiations over the usage of the water from the main tributaries of the Indus flowing from India to Pakistan commenced. The agreement eventually reached was laid down in the Indus Valley Plan, a project
financed and controlled by the World Bank and which finally started in
1960. The plan foresaw a series of barrages built on loose sandy river deposits within deep excavations reaching deep below groundwater table. For
load transfer purposes and to prevent liquefaction in case of earthquakes,
the in-situ sands below the barrages and distribution structures had to be
compacted to depths of 20 m. At Sidnai (1963), Mailsi (1965), Marala
(1966), Rasul (1966), and Chashma (1968), British and German vibrators
compacted more than 2 million m 3 of sand. Figure 2.15 gives an impression
of the considerable size of these works showing the deep excavation for the
Chashma barrage at the time of the vibro compaction works.
When the works in Pakistan were still in progress, quite complex vibro
compaction works had to be designed and carried out for an underwater
tunnel that was to connect the cities of Parana and Santa Fe in Argentina.
The 2400 m-long road tunnel was assembled from prefabricated concrete
elements, each 10.8 m in diameter and 65.5 m long, which were placed by a
lifting platform into a trench dredged out in the river bed. The double-lane
Figure 2.15 Vibro compaction works in progress at the Chashma barrage in Pakistan.
(Courtesy of Keller Group plc, London, UK.)
shifts employing up to 15 vibrators simultaneously. Compaction results
were checked continually by static cone penetration tests. The settlement
performance of the structure was as expected by the soil mechanics consultants. Measurements conducted over many years after the plant was put into
operation showed only 2–3 cm of settlement even of the heaviest footings.
After India and Pakistan gained their independence in 1947, lengthy and
difficult negotiations over the usage of the water from the main tributaries of the Indus flowing from India to Pakistan commenced. The agreement eventually reached was laid down in the Indus Valley Plan, a project
financed and controlled by the World Bank and which finally started in
1960. The plan foresaw a series of barrages built on loose sandy river deposits within deep excavations reaching deep below groundwater table. For
load transfer purposes and to prevent liquefaction in case of earthquakes,
the in-situ sands below the barrages and distribution structures had to be
compacted to depths of 20 m. At Sidnai (1963), Mailsi (1965), Marala
(1966), Rasul (1966), and Chashma (1968), British and German vibrators
compacted more than 2 million m 3 of sand. Figure 2.15 gives an impression
of the considerable size of these works showing the deep excavation for the
Chashma barrage at the time of the vibro compaction works.
When the works in Pakistan were still in progress, quite complex vibro
compaction works had to be designed and carried out for an underwater
tunnel that was to connect the cities of Parana and Santa Fe in Argentina.
The 2400 m-long road tunnel was assembled from prefabricated concrete
elements, each 10.8 m in diameter and 65.5 m long, which were placed by a
lifting platform into a trench dredged out in the river bed. The double-lane
Figure 2.15 Vibro compaction works in progress at the Chashma barrage in Pakistan.
(Courtesy of Keller Group plc, London, UK.)