Mandrel and a method for soil compaction

5- A method for soil compaction at a target location, the method comprising:

• positioning a mandrel above the target location, the mandrel comprising:
• a main drilling shaft comprising a cylindrical-shaped structure, the main drilling shaft comprising:
• a hammer insertion part positioned at a first end of the main drilling shaft;
• a bore head positioned at a second end of the main drilling shaft, the bore head being configured to tamper through hard rock surfaces;
• and
• a medium part positioned between the hammer insertion part and the bore head;
• a plurality of T-shaped elements attached around the medium part of the main drilling shaft, the plurality of T-shaped elements forming a closed octagonal from a top-view of the mandrel, wherein:
• a first size of a first cross-section at a first location from a top-view of the plurality of T-shaped elements around the medium part is larger than a second size of a second cross section at a second location from the top-view, the first location closer to the hammer insertion part and the second location closer to the bore head;
• and
• each respective T-shaped element from the plurality of T-shaped elements comprising:
• a first trapezoid-shaped plate comprising a trapezoid face;
• a second trapezoid-shaped plate comprising a first edge and a second edge, the second trapezoid-shaped plate attached from the first edge of the second trapezoid-shaped plate to the trapezoid face of the first trapezoid-shaped plate;
• a hollow cylindrical-shaped element mounted onto the main drilling shaft, the hollow cylindrical-shaped element comprising:
• a hollow-cylindrical section comprising a top surface and a bottom surface;
• a hollow-beveled section comprising a large-diameter circular surface and an outer beveled surface, the hollow-beveled section attached from the large-diameter circular surface to the bottom surface of the hollow cylindrical section;
• a plurality of parallelepiped-shaped stiffener plates, each respective parallelepiped-shaped stiffener plate from the plurality of parallelepiped-shaped stiffener plates comprising a third edge and a fourth edge, wherein the parallelepiped-shaped stiffener plate is attached from the third edge to the outer beveled surface of the hollow-beveled section and attached from the fourth edge to the medium part of the main drilling shaft.
• generating a conical-shaped cavity by driving the mandrel into the target location;
• extracting the mandrel from the conical-shaped cavity;
• generating an aggregate filled conical-shaped cavity by filling the conical-shaped cavity with aggregate;
• compacting the aggregate filled conical-shaped cavity by ramming a first hammering device onto a top surface of the aggregate filled conical-shaped cavity;
• covering the filled conical-shaped cavity with a layer of the aggregate;
• compacting the layer of the aggregate by ramming a second hammering device onto a top surface of the layer of the aggregate.

6- A method for soil compaction at a target location, the method comprising:

• positioning a conical-shaped device above the target location;
• generating a conical-shaped cavity by driving the conical-shaped device into the target location;
• extracting the conical-shaped device from the conical-shaped cavity;
• generating an aggregate filled conical-shaped cavity by filling the conical-shaped cavity with aggregate;
• compacting the aggregate filled conical-shaped cavity by ramming a first hammering device onto a top surface of the aggregate filled conical-shaped cavity;
• covering the filled conical-shaped cavity with a layer of the aggregate;
• compacting the layer of the aggregate by ramming a second hammering device onto a top surface of the layer of the aggregate. 7- The method of claim 7, wherein positioning the conical-shaped device above the target location comprises positioning a mandrel above the target location, the mandrel comprising:
• a main drilling shaft comprising a cylindrical-shaped structure, the main drilling shaft comprising:
• a hammer insertion part positioned at a first end of the main drilling shaft;
• a bore head positioned at a second end of the main drilling shaft, the bore head being configured to tamper through hard rock surfaces;
• and
• a medium part positioned between the hammer insertion part and the bore head;
• a plurality of T-shaped elements mounted around the medium part of the main drilling shaft, the plurality of T-shaped elements forming a closed octagonal from a top-view of the mandrel, wherein
• each respective T-shaped element from the plurality of T-shaped elements comprising:
• a first trapezoid-shaped plate comprising a trapezoid face;
• a second trapezoid-shaped plate comprising a first edge and a second edge, the second trapezoid-shaped plate attached from the first edge of the second trapezoid-shaped plate to the trapezoid face of the first trapezoid-shaped plate;
• a hollow cylindrical-shaped element mounted onto the main drilling shaft, the hollow cylindrical-shaped element comprising:
• a hollow-cylindrical section comprising a top surface and a bottom surface;
• a hollow-beveled section comprising a large-diameter circular surface and an outer beveled surface, the hollow-beveled section attached from the large-diameter circular surface to the bottom surface of the hollow cylindrical section;
• a plurality of parallelepiped-shaped stiffener plates, each respective parallelepiped-shaped stiffener plate from the plurality of parallelepiped-shaped stiffener plates comprising a third edge and a fourth edge, wherein each respective parallelepiped-shaped stiffener plate is attached at the respective third edge to the outer beveled surface of the hollow-beveled section and attached at the respective fourth edge to the medium part of the main drilling shaft.

11- The method of claim 6, wherein compacting the aggregate filled conical-shaped cavity by ramming the first hammering device onto a top surface of the aggregate filled conical-shaped cavity comprises compacting the aggregate filled conical-shaped cavity by ramming a high-frequency impact tamper onto a top surface of the aggregate filled conical-shaped cavity, the high-frequency impact tamper comprising:

• a rod comprising a first end and a second end, the rod being inserted in the mechanical vibratory hammer from the first end of the rod;
• and
• a ramming head attached to the rod;
• the ramming head comprising:
• a rod attaching section, wherein the ramming head attached from the rod attaching section to the second end of the rod;
• a beveled-shaped ramming tip;
• and
• a cylindrical section positioned between the rod attaching section and the beveled-shaped ramming tip.

13- The method of claim 6, wherein compacting the layer of aggregate by ramming the second hammering device onto a top surface of the layer of aggregate comprises compacting the layer of aggregate by ramming a sheep foot compacting device onto a top surface of the layer of aggregate, the sheep foot compacting device comprising:

• a rod comprising a first end and a second end, wherein the rod being inserted in the mechanical vibratory hammer from the first end of the rod;
• a beveled-shaped element comprising a top end and a bottom end, the bevel-shaped element attached from the top end of the beveled-shaped element to the second end of the rod;
• and
• a reduced conical tip attached to the bottom end of the beveled-shaped element.