Abstract: A method and apparatus for forming a support aggregate pier having compacted aggregate lifts in a soil matrix, includes an elongate, hollow tube with a bulbous leading end bottom head element that is forced or lowered into the soil matrix. The hollow tube includes a mechanism for releasing aggregate from the lower head element of the tube as the tube is lifted in predetermined increments. The same hollow tube is then lowered or pushed in predetermined increments to vertically compact the released aggregate in thin aggregate lifts, while forcing a portion of the compacted aggregate transaxially into the soil matrix at the sidewalls of the cavity. The process may be repeated to form a series of compacted aggregate lifts comprising an aggregate pier or the process may include forming only a single lift for the aggregate pier while densifying adjacent matrix soils and imparting lateral stress in these soils.

Abstract: Extensible shells and related methods for constructing a support pier are disclosed. A shell can define an interior for holding granular construction material and define an opening for receiving the granular construction material into the interior. The shell can be flexible such that the shell expands when granular construction material is compacted in the interior of the shell. A method may include positioning the shell in the ground and filling at least a portion of the interior of the shell with the granular construction material. The granular construction material may be compacted in the interior of the shell to form a support pier.

Abstract: An apparatus and method for ground improvement includes a device having a plurality of tines extending downwardly from a top plate in a manner to achieve displacement of ground material downward and radially outward. The tines may include ridges spaced vertically along an outer surface of the tines. The tines may also be in the form of opposing plates. The device is mechanically driven into the ground to achieve predetermined depths of penetration by the tines/plates. The device is retracted and driven repeatedly to achieve densification. Optionally, voids made by the device can be filled with a flowable media.

Abstract: An apparatus and method for ground improvement includes a device having a plurality of tines extending downwardly from a top plate in a manner to achieve displacement of ground material downward and radially outward. The device is mechanically driven into the ground to achieve predetermined depths of penetration by the tines. The device is retracted and driven repeatedly to achieve densification. Optionally, voids made by the device can be filled with a flowable media.

Abstract: A soil densification system and method is disclosed. The presently disclosed soil densification system includes an air delivery probe or pipe that can be driven or otherwise installed into a soil mass. An inlet of the air delivery probe is supplied by an air compressor and an air storage tank, which are used for the rapid delivery of air impulses or bursts into the air delivery probe, whereas the air impulses or bursts are expelled out of an outlet of the air delivery probe and into the soil mass. The method of using the presently disclosed soil densification system includes the steps of inserting the end of the air delivery probe into the soil mass to any desired depth and then releasing an impulse or burst of air into the soil mass, thereby forming a densified region in the soil mass via the forces of the air impulse.

Abstract: A primary earth penetrating mandrel formed of a hollow shell steel plate has an upper end and an open lower end joined by an upwardly and outwardly tapered wall. The mandrel is driven downwardly in the earth to simultaneously form a vertical cavity while compacting the sidewall of the cavity to provide structural integrity. The mandrel is then moved upwardly from the bottom of the cavity and aggregate is deposited in the bottom of the cavity following which the mandrel is lowered so that its lower end engages the deposited aggregate and densifies the aggregate by vertical vibratory action and static force with these steps being repeated until the pier top is near the surface of the earth. A second embodiment includes a conduit in the primary mandrel for injecting concrete or grout into aggregate previously deposited in the cavity.

Abstract: A soil reinforcement system including angled soil reinforcement elements to resist seismic shear forces and methods of making same are disclosed. For example, the soil reinforcement system includes an array or grid of angled soil reinforcement elements installed within the ground, wherein the angled reinforcement elements are designed to absorb and/or resist earthquake-induced seismic shear forces by transferring the applied shear forces into axial compressive and tensile forces within each of the angled reinforcement elements.

Abstract: A primary earth penetrating mandrel formed of a hollow shell steel plate octagonal in cross-section has an upper end and a blunt lower end joined by an upwardly and outwardly tapered wall. The mandrel is driven downwardly in the earth to simultaneously form a vertical tapered cavity while compacting the sidewall of the cavity to provide structural integrity. The mandrel is then moved upwardly from the bottom of the cavity and aggregate is deposited in the bottom of the cavity following which the mandrel is lowered so that its blunt lower end engages the deposited aggregate and densifies the aggregate by vertical vibratory action and static force with these steps being repeated until the pier top is near the surface of the earth at which time the upper aggregate portions are densified by either the primary mandrel or a secondary mandrel having a substantially larger lower end surface than the lower end surface of the primary mandrel.

Abstract: Extensible shells and related methods for constructing a support pier are disclosed. A shell can define an interior for holding granular construction material and define an opening for receiving the granular construction material into the interior. The shell can be flexible such that the shell expands when granular construction material is compacted in the interior of the shell. A method may include positioning the shell in the ground and filling at least a portion of the interior of the shell with the granular construction material. The granular construction material may be compacted in the interior of the shell to form a support pier.

Abstract: A tamper device including a shaft for driving a tamper head, and a shield. A tamper head is attached to the end of the shaft for tamping a lift of aggregate in a cavity formed in a ground surface. A shield attached to the tamper device and spaced a predetermined distance above a top surface of the tamper head, the shield having a predetermined length extending upwardly above the tamper head sufficient to prevent sidewalls of a cavity in soft soil in which the tamper device is used from failing and collapsing into the cavity. Methods of constructing aggregate columns with thicker lifts are also disclosed.

Abstract: A system and method of determining lift deflection during construction of aggregate columns allows for real time monitoring of construction to ensure meeting defined parameters. The amount of deflection of a tamper head during tamping is determined multiple times for each lift. When the amount of deflection matches a predetermined value, tamping is stopped.

Abstract: A method for ground improvement with hardened inclusions includes providing a device having a plurality of tines extending downwardly from a top plate in a manner to achieve displacement of ground material downward and radially outward. The device is mechanically driven into the ground to achieve predetermined depths of penetration by the tines and to create cavities at the location the tines are advanced. The device is at least partially retracted and hardening cementitious material backfill is added into the cavities for forming a plurality of hardened inclusions within the cavities.

Abstract: An apparatus and method for ground improvement includes a device having a plurality of tines extending downwardly from a top plate in a manner to achieve displacement of ground material downward and radially outward. The device is mechanically driven into the ground to achieve predetermined depths of penetration by the tines. The device is retracted and driven repeatedly to achieve densification. Optionally, voids made by the device can be filled with a flowable media.

Abstract: A system and method of determining lift deflection during construction of aggregate columns allows for real time monitoring of construction to ensure meeting defined parameters. The amount of deflection of a tamper head during tamping is determined multiple times for each lift. When the amount of deflection matches a predetermined value, tamping is stopped.

Abstract: An apparatus and method for ground improvement includes a device having a plurality of tines extending downwardly from a top plate in a manner to achieve displacement of ground material downward and radially outward. The device is mechanically driven into the ground to achieve predetermined depths of penetration by the tines. The device is retracted and driven repeatedly to achieve densification. Optionally, voids made by the device can be filled with a flowable media.

Abstract: Extensible shells and related methods for constructing a support pier are disclosed. A shell can define an interior for holding granular construction material and define an opening for receiving the granular construction material into the interior. The shell can be flexible such that the shell expands when granular construction material is compacted in the interior of the shell. A method may include positioning the shell in the ground and filling at least a portion of the interior of the shell with the granular construction material. The granular construction material may be compacted in the interior of the shell to form a support pier.

Abstract: A primary earth penetrating mandrel formed of a hollow shell steel plate octagonal in cross-section has an upper end and a blunt lower end joined by an upwardly and outwardly tapered wall. The mandrel is driven down in the earth to simultaneously form a vertical tapered cavity while compacting the sidewall of the cavity to provide structural integrity. The mandrel is then moved upwardly from the bottom of the cavity and aggregate is deposited in the bottom of the cavity then the mandrel is lowered so that its blunt lower end densifies the aggregate by vertical vibratory action and static force and repeating these until the pier top is near the surface of the earth at which time the upper aggregate portions are densified by the primary mandrel or a secondary mandrel having a substantially larger lower end surface than the lower end surface of the primary mandrel.

Abstract: A tamper device including a shaft for driving a tamper head, and a shield. A tamper head is attached to the end of the shaft for tamping a lift of aggregate in a cavity formed in a ground surface. A shield attached to the tamper device and spaced a predetermined distance above a top surface of the tamper head, the shield having a predetermined length extending upwardly above the tamper head sufficient to prevent sidewalls of a cavity in soft soil in which the tamper device is used from failing and collapsing into the cavity. Methods of constructing aggregate columns with thicker lifts are also disclosed.

Abstract: A primary earth penetrating mandrel formed of a hollow shell steel plate octagonal in cross-section has an upper end and a blunt lower end joined by an upwardly and outwardly tapered wall. The mandrel is driven down in the earth to simultaneously form a vertical tapered cavity while compacting the sidewall of the cavity to provide structural integrity. The mandrel is then moved upwardly from the bottom of the cavity and aggregate is deposited in the bottom of the cavity then the mandrel is lowered so that its blunt lower end densifies the aggregate by vertical vibratory action and static force and repeating these until the pier top is near the surface of the earth at which time the upper aggregate portions are densified by the primary mandrel or a secondary mandrel having a substantially larger lower end surface than the lower end surface of the primary mandrel.

Abstract: A method and apparatus for forming a support aggregate pier having compacted aggregate lifts in a soil matrix, includes an elongate, hollow tube with a bulbous leading end bottom head element that is forced or lowered into the soil matrix. The hollow tube includes a mechanism for releasing aggregate from the lower head element of the tube as the tube is lifted in predetermined increments. The same hollow tube is then lowered or pushed in predetermined increments to vertically compact the released aggregate in thin aggregate lifts, while forcing a portion of the compacted aggregate transaxially into the soil matrix at the sidewalls of the cavity. The process may be repeated to form a series of compacted aggregate lifts comprising an aggregate pier or the process may include forming only a single lift for the aggregate pier while densifying adjacent matrix soils and imparting lateral stress in these soils.