In order to obtain the actual data of the anti-pull force of the ground pile, The Mount Makers’ staffs did the test using the different types of piles.
1、Ground pile type
2、Test site: Agricultural land in Huangtang, Jiangyin
According to site exploration, the land is a natural sandy clay soil.
Reference to national norms: Land N value: 15 ~ 30 (640mm below), the surface soil N value: 5-8 (0-640mm below the surface)
3、Fixed point
In order to ensure that all of the ground piles’ conditions are the same, the piles were hit in the same region within the same straight line and set aside 3 meters spacing to facilitate subsequent operations.
4、Piling
In order to make the test data closer to the project site, ground screws were spiral into the ground and single pile was pushed the down way.
5、The exposed ground height of ground piles
Under the condition of site construction, two types of pile in the three test piles reached the normal entry value. Large leaf ground screw on site had entered the limit, the site torque can not continue to the pile into the ground.
6、Remove ground piles
After standing 2 hours with all piles into the ground , until the land resumed, the piles began to prepare to be removed.
7、Test analysis
It was known from soil samples taken from large leaf ground screw, it was driven into the 1140mm underground, 560mm was good soil layer, so the main tough layer shall prevail from the surface below 580mm.
8、The result
According to the soil samples, we can know the tough layer shall prevail from the surface below 580mm.
Ground pile type |
Driven pile depth |
Tough layer depth |
Anti-pull force |
76*1600Ground screw |
1330mm |
750mm |
2178kg |
60*2000Single pile |
1540mm |
960mm |
1090kg |
76*2690Large leaf ground screw |
1140mm |
860mm |
3188kg |
From the above we can see that the order of pile strength to anti-pull force was:
Single pile<Ground screw<Large leaf ground screw