A depth vibrator for compacting soil, comprising a rotary drive (3); a drive shaft (4), which is rotatingly drivable about a rotary axis (A) by the rotary drive (3) in a first rotation direction (R1) and in an opposite second rotation direction (R2); a primary mass body (5) connected non-rotatably to the drive shaft (4) and rotates together with the latter about the rotary axis (A); a secondary mass body (6), which is movable into a first rotation position (P1) relative to the primary mass body (5) by rotation of the drive shaft (4) in the first rotation direction (R1) and which is movable into a second rotation position (P2) by rotation of the drive shaft (4) in the second rotation direction (R2). In the first and second rotation position (P1) the secondary mass body (6) can be rotated together with the primary mass body (5) about the rotary axis (A); and the center of mass (S6) of the secondary mass body (6) and the center of mass (S5) of the primary mass body (5) have different radial distances from the rotary axis (A).

A hybrid foundation structure includes a first perforation hole formed in the ground, at least one second perforation hole formed adjacent to the first perforation hole on a side surface of the first perforation hole, and a first pile and a second pile formed by mixing and injecting soil and soil solidifying agent into the first perforation hole and the second perforation hole.

An apparatus intended for incorporation as a module within ground improvement pokers such as those already patented (U.S. Pat. No. 6,554,543 and U.S. Pat. No. 8,419,316) in order to enhance the field performance of those hydrodynamic compactors by either improving their ground penetration capability, and/or, maintaining or recovering the permeability of their outer seepage filtration element; involving a method which can be activated remotely at the operator's discretion, while those parent devices are at depth within the earth. This apparatus and method may have application in water well installations and reviving flow in oil wells.

An apparatus intended for incorporation as a module within ground improvement pokers such as those already patented (U.S. Pat. No. 6,554,543 and U.S. Pat. No. 8,419,316) in order to enhance the field performance of those hydrodynamic compactors by either improving their ground penetration capability, and/or, maintaining or recovering the permeability of their outer seepage filtration element; involving a method which can be activated remotely at the operator's discretion, while those parent devices are at depth within the earth. This apparatus and method may have application in water well installations and reviving flow in oil wells.

Systems and methods for soil improvement foundation isolation and load spreading are provided. The systems and methods provided herein relate to isolation of structural foundations from soil improvement elements and distributing stress from high stiffness elements to lower stiffness materials. A shear load transfer reduction system may include one or more ground improvement elements for supporting an applied load. A shear break element may be positioned above one or more ground improvement elements. The shear break elements may be configured to have low interface shear strength.

A jet grouting method is capable of reducing an unnecessary portion (redundant portion) exceeding an effective wall thickness without narrowing a construction pitch, and capable of allowing easy mechanical control. A ground improvement structure including a plurality of ground improvement bodies is constructed through use of the jet grouting method. Each of the ground improvement bodies is constructed so as to have a sectional shape formed by a combination of different kinds of fan shapes having different radiuses. The sectional shape of the ground improvement body is a combination of at least two kinds of fan shapes. One of the kinds of the fan shapes corresponds to a fan shape with a smaller radius, and the other corresponds to a fan shape with a larger radius. The sectional shape of the improvement body has a minimum diameter portion formed of the fan shapes with the smallest radius and a maximum diameter portion formed of the fan shapes with the largest radius. When designing the ground improvement body, a central angle is determined from a fan shape having the smallest radius with respect to the effective wall thickness. When constructing the ground improvement body, a diameter thereof is controlled by stepwisely changing a rotation speed of the injection rod. At that time, a soil breaking achieved by an improving material injected at high pressure is monitored so as to check the diameter of the ground improvement body and the effective thickness thereof.

The system, method and apparatus described relates generally to a method of Direct Power Compaction (DPC). In one example embodiment to methods, apparatus, and systems to compact loose ground by vibration and compaction of H piles driven by vibrators or drivers (vibro-hammer). The DPC method is an efficient and highly economical technique for densifying loose soils. In the procedure piles, with an innovative H pattern structure, are driven in the ground using a combination of downward and vibratory force to move particles of the loose or sandy soil closer together and reduce the voids between them. Subsequent backfilling and vibration at the H-pile sites achieves the highest density possible and provides for an improvement ground soil structure and load bearing capacity.

The system, method and apparatus described relates generally to a method of Direct Power Compaction (DPC). In one example embodiment to methods, apparatus, and systems to compact loose ground by vibration and compaction of H piles driven by vibrators or drivers (vibro-hammer). The DPC method is an efficient and highly economical technique for densifying loose soils. In the procedure piles, with an innovative H pattern structure, are driven in the ground using a combination of downward and vibratory force to move particles of the loose or sandy soil closer together and reduce the voids between them. Subsequent backfilling and vibration at the H-pile sites achieves the highest density possible and provides for an improvement ground soil structure and load bearing capacity.

A mallet is described that has at least one cleft, in such a structure that the stress wave created during impact has longer travel way than the length of the mallet as measured along the impact line. This mallet induces longer-lasting and weaker stress wave(s) in the anvil as compared to a solid mallet having the same outer dimensions and more or less the same weight. The Cleft-Mallet increases the effectiveness of the strike, while decreasing the stresses in the anvil.

A mallet is described that has at least one cleft, in such a structure that the stress wave created during impact has longer travel way than the length of the mallet as measured along the impact line. This mallet induces longer-lasting and weaker stress wave(s) in the anvil as compared to a solid mallet having the same outer dimensions and more or less the same weight. The Cleft-Mallet increases the effectiveness of the strike, while decreasing the stresses in the anvil.