Abstract: A retrofit reinforcing structure addition and method for an existing gravity spread foundation for a wind turbine or the like having a central pedestal and a spread section is provided. The retrofit structure addition includes a collar formed around the pedestal of the spread foundation. The collar is formed by a shape sustaining member, such as a CMP, placed around the pedestal to define an annular ring between the CMP and the pedestal that is filled with cementitious material. Radial bolts extend horizontally through the collar and into the side of the pedestal. Soil and/or rock anchor bolts extend vertically through the collar, the spread portion of the foundation and into the underlying soil and/or rock substrate. The radial and anchor bolts are post-tensioned to ensure that the cementitious material of the collar remains in compression and the bolts are always in static tension, strengthening the original gravity spread foundation and extending the fatigue life thereof.

Abstract: A post-tensioned continuous strand hoop reinforcement for concrete foundations is provided. The post-tensioned continuous strand hoop reinforcement compresses the concrete to prevent cracking and significantly reduces foundation deflection and distortion which increases rotational stiffness in anchor caps, spread foundations, and like foundation configurations.

Abstract: A post-tensioned concrete cap foundation has helical anchors with pipes having several helical discs welded around the pipe perimeter to spin drill deep into subsurface soils or other soft materials with holes in the pipe for high pressure-grouting in place. The helical anchor pipes include a tensioning element for pulling and post-tensioning the helical anchor. The helical anchors are tension anchors which can be converted to compression anchors. The helical anchors in tension serve to pull the foundation cap down to compress the underlying soil while the compression anchors limit the maximum settlement of the concrete foundation cap. The foundation also includes perimeter-forming and interior corrugated metal pipes with upper and lower sleeved horizontally extending radial bolts that are secured to the pipes and post-tensioned to provide lateral foundation compression.

Abstract: A post-tensioned concrete cap foundation has helical anchors with pipes having several helical discs welded around the pipe perimeter to spin drill deep into subsurface soils or other soft materials with holes in the pipe for high pressure-grouting in place. The helical anchor pipes include a tensioning element for pulling and post-tensioning the helical anchor. The helical anchors are tension anchors which can be converted to compression anchors. The helical anchors in tension serve to pull the foundation cap down to compress the underlying soil while the compression anchors limit the maximum settlement of the concrete foundation cap. The foundation also includes perimeter-forming and interior corrugated metal pipes with upper and lower sleeved horizontally extending radial bolts that are secured to the pipes and post-tensioned to provide lateral foundation compression.

Abstract: A post-tensioned concrete cap foundation has helical anchors with pipes having several helical discs welded around the pipe perimeter to spin drill deep into subsurface soils or other soft materials with holes in the pipe for high pressure-grouting in place. The helical anchor pipes include a tensioning element for pulling and post-tensioning the helical anchor. The helical anchors are tension anchors which can be converted to compression anchors. The helical anchors in tension serve to pull the foundation cap down to compress the underlying soil while the compression anchors limit the maximum settlement of the concrete foundation cap. The foundation also includes perimeter-forming and interior corrugated metal pipes with upper and lower sleeved horizontally extending radial bolts that are secured to the pipes and post-tensioned to provide lateral foundation compression.

Abstract: A perimeter pile anchor foundation is built by forming a plurality of individual perimeter pile anchors in a large generally circular pattern to form a perimeter wall. The individual pile anchors are contiguous, each pile overlapping the adjacent piles on either side. The overlapping pile anchors form an arch such that compression and friction between the pile anchors resist soil caving and sloughing pressure when soil inside the perimeter wall is excavated, enabling the perimeter pile foundation to be effectively constructed in weak saturated soils and/or cohesionless sands that will not allow conventional concrete foundation excavations. A concrete foundation ring is formed inside the pile perimeter wall to support a tall and/or heavy tower or other structure subject to high upset forces.

Abstract: A post-tensioned concrete cap foundation has helical anchors with pipes having several helical discs welded around the pipe perimeter to spin drill deep into subsurface soils or other soft materials with holes in the pipe for high pressure-grouting in place. The helical anchor pipes are coupled to a tensioning element for pulling and post-tensioning the helical anchor. The helical anchors are tension anchors which can be converted to compression anchors. The helical anchors in tension serve to pull the foundation cap down to compress the underlying soil while the compression anchors limit the maximum settlement of the concrete foundation cap. The foundation also includes perimeter-forming and interior corrugated metal pipes with upper and lower sleeved horizontally extending radial bolts that are secured to the pipes and post-tensioned to provide lateral foundation compression.

Abstract: A post-tensioned concrete cap foundation has helical anchors with pipes having several helical discs welded around the pipe perimeter to spin drill deep into subsurface soils or other soft materials with holes in the pipe for high pressure-grouting in place. The helical anchor pipes are coupled to a tensioning element for pulling and post-tensioning the helical anchor. The helical anchors are tension anchors which can be converted to compression anchors. The helical anchors in tension serve to pull the foundation cap down to compress the underlying soil while the compression anchors limit the maximum settlement of the concrete foundation cap. The foundation also includes perimeter-forming and interior corrugated metal pipes with upper and lower sleeved horizontally extending radial bolts that are secured to the pipes and post-tensioned to provide lateral foundation compression.

Abstract: A circular concrete cap foundation poured in-situ within a perimeter forming corrugated metal pipe set atop or within an excavated pit and enclosing a series of circumferentially spaced pile anchors. The circular concrete cap foundation supports sets of inner and outer circumferentially spaced tower anchor bolts having their lower ends anchored to an embedded anchor ring and their upper ends projecting vertically and upwardly out the top of the circular foundation to engage the base flange of a supported tower. The pile anchors are formed with perimeter corrugated metal pipes set deep in subsurface soils with cementitious material surrounding and partially bonding to a centralized steel bolt or tendon which extends through the cap foundation. The tower anchor bolts and the pile anchor bolts are both partially encased in a PVC sleeve so that the bolts can be post-tensioned. The pile anchors are in tension only and serve to pull the cap foundation down to compress the underlying ground soils.

Abstract: A post-tensioned pile anchor foundation and method therefor creates a void or highly compressible region between a drilled or driven pile anchor surrounding a post-tensioned anchor bolt or tendon and the bottom of a foundation cap. The void or compressible region can be formed by compressible spacers or void forming elements placed between the top of the pile anchor and the concrete cap. As the anchor bolt or tendon is post-tensioned against the cap, the void forming element is compressed or crushed, allowing the cap to be pulled downwardly and the pile anchor to be pulled upwardly toward the cap against the resistance of the surrounding soil.

Abstract: A support tower for heavy loads or large structures such as a wind turbine generators, constructed of a plurality of telescopic tower sections with the outer lower tower section having a lower end supported from a foundation and at least one or more inner upper tower sections telescoped in an initial vertical nested relation within the outer lower tower section. The heavy load is mounted on an upper end of the inner upper tower section while in the initial vertical nested relation. The inner upper tower section or sections are then lifted upwardly to an extended tower height by lift mechanisms and the tower sections are secured in vertically extended position by inter-engaging wedge joint structure with bolt fasteners extending through mating wedge surfaces to retain the telescopic tower sections vertically extended and position the heavy load in a vertically elevated position.

Abstract: A circular concrete cap foundation poured in-situ within a perimeter forming corrugated metal pipe set atop or within an excavated pit and enclosing a series of circumferentially spaced pile anchors. The circular concrete cap foundation supports sets of inner and outer circumferentially spaced tower anchor bolts having their lower ends anchored to an embedded anchor ring and their upper ends projecting vertically and upwardly out the top of the circular foundation to engage the base flange of a supported tower. The pile anchors are formed with perimeter corrugated metal pipes set deep in subsurface soils with cementitious material surrounding and partially bonding to a centralized steel bolt or tendon which extends through the cap foundation. The tower anchor bolts and the pile anchor bolts are both partially encased in a PVC sleeve so that the bolts can be post-tensioned. The pile anchors are in tension only and serve to pull the cap foundation down to compress the underlying ground soils.

Abstract: A circular concrete cap foundation poured in-situ within a perimeter forming corrugated metal pipe set atop or within an excavated pit and enclosing a series of circumferentially spaced pile anchors. The circular concrete cap foundation supports sets of inner and outer circumferentially spaced tower anchor bolts having their lower ends anchored to an embedded anchor ring and their upper ends projecting vertically and upwardly out the top of the circular foundation to engage the base flange of a supported tower. The pile anchors are formed with perimeter corrugated metal pipes set deep in subsurface soils with cementitious material surrounding and partially bonding to a centralized steel bolt or tendon which extends through the cap foundation. The tower anchor bolts and the pile anchor bolts are both partially encased in a PVC sleeve so that the bolts can be post-tensioned. The pile anchors are in tension only and serve to pull the cap foundation down to compress the underlying ground soils.

Abstract: A perimeter weighted foundation has a central pier pedestal and an enlarged base spaced outwardly and extending below the pedestal. The enlarged base includes an outer concentric perimeter wall section with a radially extending, disk-shaped spread section interconnecting the bottom of the pedestal section and the top of the perimeter wall section. The pedestal section includes vertically extending post-tensioning anchor bolts sleeved through substantially the entire height of the cylindrical pedestal in accordance with earlier U.S. Pat. Nos. 5,586,417 and 5,826,387 and the spread section includes two layers of similarly sleeved post-tensioning bolts which extend through the bottom of the pedestal section and into or through the top of the perimeter wall section, thus tying together the enlarged base to the pier pedestal.

Abstract: A support tower for large structures such as wind turbines generators, microwave structures, high voltage transmission lines or the like, constructed of telescopic sections with the lowermost section having an edge portion pivotally connected to a foundation to enable the tower sections to be transported to the site of installation. The tower sections are assembled at the installation site in a nested relationship, each within the adjacent lower tower section. The large load is mounted on the upper end of the uppermost tower section and the nested tower sections are then tilted upwardly to a vertical position. After the tower is tilted to its vertical position and securely connected to the foundation, the telescopic tower sections are vertically extended to position the load in a vertically elevated position.

Abstract: A circular concrete cap foundation poured in-situ within a perimeter forming corrugated metal pipe set atop or within an excavated pit and enclosing a series of circumferentially spaced pile anchors. The circular concrete cap foundation supports sets of inner and outer circumferentially spaced tower anchor bolts having their lower ends anchored to an embedded anchor ring and their upper ends projecting vertically and upwardly out the top of the circular foundation to engage the base flange of a supported tower. The pile anchors are formed with perimeter corrugated metal pipes set deep in subsurface soils with cementitious material surrounding and partially bonding to a centralized steel bolt or tendon which extends through the cap foundation. The tower anchor bolts and the pile anchor bolts are both partially encased in a PVC sleeve so that the bolts can be post-tensioned. The pile anchors are in tension only and serve to pull the cap foundation down to compress the underlying ground soils.

Abstract: A perimeter weighted foundation has a central pier pedestal and an enlarged base spaced outwardly and extending below the pedestal. The enlarged base includes an outer concentric perimeter wall section with a radially extending, disk-shaped spread section interconnecting the bottom of the pedestal section and the top of the perimeter wall section. The pedestal section includes vertically extending post-tensioning anchor bolts sleeved through substantially the entire height of the cylindrical pedestal in accordance with earlier U.S. Pat. Nos. 5,586,417 and 5,826,387 and the spread section includes two layers of similarly sleeved post-tensioning bolts which extend through the bottom of the pedestal section and into or through the top of the perimeter wall section, thus tying together the enlarged base to the pier pedestal.

Abstract: A perimeter weighted foundation has a central pier pedestal and a base extending outwardly from and below the pier pedestal. The base includes an outer perimeter wall section and a radially extending, disk-shaped spread section interconnecting the bottom of the pier pedestal and the top of the perimeter wall section with the top surface of the spread section being positioned substantially below the top of the pier pedestal. The pier pedestal includes vertical post tensioned anchor bolts in accordance with U.S. Pat. Nos. 5,586,417 and 5,826,387. The spread section includes two layers of sleeved post tensioned bolts which extend through the bottom of the pier pedestal, through the spread section and into the top of the perimeter wall section to post tension the perimeter wall section, the spread section and the pier pedestal.

Abstract: A perimeter weighted foundation has a central pier pedestal and an enlarged base spaced outwardly and extending below the pedestal. The enlarged base includes an outer concentric perimeter wall section with a radially extending, disk-shaped spread section interconnecting the bottom of the pedestal section and the top of the perimeter wall section. The pedestal section includes vertically extending post-tensioning anchor bolts sleeved through substantially the entire height of the cylindrical pedestal in accordance with earlier U.S. Pat. Nos. 5,586,417 and 5,826,387 and the spread section includes two layers of similarly sleeved post-tensioning bolts which extend through the bottom of the pedestal section and into or through the top of the perimeter wall section, thus tying together the enlarged base to the pier pedestal.

Abstract: A support tower for large structures such as wind turbines generators, microwave structures, high voltage transmission lines or the like, constructed of telescopic sections with the lowermost section having an edge portion pivotally connected to a foundation to enable the tower sections to be transported to the site of installation. The tower sections are assembled at the installation site in a nested relationship, each within the adjacent lower tower section. The large load is mounted on the upper end of the uppermost tower section and the nested tower sections are then tilted upwardly to a vertical position. After the tower is tilted to its vertical position and securely connected to the foundation, the telescopic tower sections are vertically extended to position the load in a vertically elevated position.