00:01
Hello students, a three -story structure is to be constructed.
00:07
So this is a three -story structure, three -story building is to be constructed.
00:13
So the area is 800 sorry 8000 meter square.
00:18
So that is the area.
00:20
Now the initial subsurface exploration indicates that the presence of sinkholes or voids are there in the area right sinkholes and voids are there.
00:31
So it could go down once the building is there.
00:35
It could have gradual movement of the soil beneath and it could collapse.
00:41
So that is a possibility.
00:43
The predominant soil type is city sand, fine sand grading to a fine sand with seams of sandy clay.
00:53
So it's a sandy shallow surface and the design indicates that the shallow foundations can be used to for use for this project provided the soils are made more homogeneous as far as the load support is there and also the voids are not present within a depth of at least 7 .6 meters.
01:17
So to conduct a preliminary design for this dynamic compaction project, we need to consider factors like first factor is drop height.
01:30
So drop height is the distance between the tamper and the ground at the time of impact.
01:36
So when you drop something it has it makes a collapse right collapse on the sand.
01:42
So what is the distance between the height and collapse? so h by c is called drop height.
01:51
So it affects the energy transfer to the ground and the depth of the compaction achieved.
01:56
Drop height should be chosen based upon the soil conditions and desired compact depth.
02:02
Typically drop heights range from 1 to 2 meters.
02:06
So you have to consider an average tamper height of at least 1 .4 meters and choose a drop height of 1 .4 meters.
02:16
Okay, so that is 1 .4 meters you have to choose.
02:21
Second is spacing.
02:23
So the spacing refers to the distance between each drop point.
02:29
Okay, this is the first drop point, the second drop point, third drop point.
02:33
So that that spacing between them is called spacing.
02:37
So it affects the coverage area of compaction.
02:43
So the spacing should be chosen based upon the desired level of compaction and the soil's response dynamics.
02:52
You can use a common spacing is 1 .5 to 3 times the tamper diameter.
02:57
Okay, you can go from 1 .5 to 3 times 1 .4.
03:02
So this is what you can choose.
03:07
Now, third one is number of drops...