Commercial projects require skill, attention to detail and efficient installation. Engineers, architects and other industry professionals have relied on our experience to get the job quickly and correctly.
Drilled Hollow Bar Micropiles
- Capable of one step fast installation
- Allows simultaneous drilling and grouting
- Allows the use of smaller equipment at lower cost
- Allows low overhead, limited access installation
- Improves the ground (densification)
- Offers higher skin friction than conventional piles
- Can be socketed into rock
- Can be installed in any soil condition
Drilled Hollow Bar Micropile Projects
An existing building was reconfigured to house a new processing facility. It was a former furniture depot being converted to industrial plant. To accommodate the new overhead cranes and press pits, the existing and new columns needed to bear on a deep foundation system. The site was overlain with engineered fill and bearing rock was located about ten feet down. United Dynamics, Inc. socketed over 200 micropiles into the limestone at depths ranging from 25-40’. Once installed, steel support structures were tied to the micropiles creating load transfer from the columns to the piles. The ease of installation coupled with small tolerances proved to be ideal for the micropile.
An undeveloped parcel of land in New Albany, IN was to be the site of a new Porter Paints Store. Several years ago there was actually a home at this site that United Dynamics, Inc. had repaired. City planners acquired and demolished the house for the widening of Mt. Tabor Rd. and used the site to haul their spoils from the road widening. When construction was ready to begin, the site was built up fill for about 20’. United Dynamics, Inc. installed hollow bar micropiles to pass through the urban fill material into the native soils and rock. Micropiles were installed along the perimeter foundation as well as strategic points in the thickened slab. From start to finish United Dynamics, Inc. was able to complete this project in just under a week.
Auto Glass Company
United Dynamics, Inc. was contracted to install a deep foundation system for new isolation pads. Sitting atop the large isolation pads would be large fan/vacuums that created a tremendous amount of vibration. The micropiles allowed the design engineer to transfer that energy deeper than then surrounding building foundations. Our crew was originally going to install the micropiles prior to the erection of the steel building surrounding the fans. Because of scheduling demands, the general contractor elected to erect the steel skeleton and cladding of the building prior to the installation of the piles. By strategically installing the piles, we were able to stay on schedule and turn the building back over to the general contractor in a matter of days.
Washington Middle School
Washington Middle School was being renovated when it was discovered it was experiencing differential settlement. Soil borings indicated the presence of fill material below the foundation. Both traditional steel resistance underpinning and helical underpinning were originally selected by the design engineers as the choice of remediation. Upon review of the soil information, UDI were concerned with the capabilities of these underpinning methods. It would be possible for the helical piers to encounter cobbles/floaters in the fill thus negating the installation. The resistance piers likewise could become compromised by the nature of the fill. UDI proposed the installation of small diameter micropiles. The main advantage of the method would be the penetration of the fill material (coring if needed) to the ‘good’ material below.
The passive installation of the micropiles would also allow for a greater factor of safety in strength and parameters.UDI mated Titan’s 40/20mm hollow bar micropiles with ECP’s MP 350 Underpinning Bracket (75,000-99,000 lbs capacity) to provide a competent underpinning system. UDI excavated the site and prepared the footings during the first day of operation. Once the brackets were mounted, we installed the micropiles, coring and simultaneously grouting the bars as they drilled 35’ into the good strata. By utilizing this application, UDI was able to complete the project with a three man crew in just over three days. Our vast experience in dealing with different underpinning techniques provided an economical solution to an otherwise difficult situation.
- Ease of Installation
- Little to No Vibration
- Immediate Load Transfer upon Installation
- Installed Torque Correlates to Capacity
- Easily Load Tested to Verify Capacity
- Installs Below Active Soils
- All Weather Installation
- Little to No Disturbance to Job-site
Helical Micropiles Projects
A new chemical dryer needed to be installed at an existing plant in Louisville, KY. United Dynamics, Inc., having previously worked with design engineer, was selected to install helical micropiles into the native sands to support the column loads in both tension and compression. By utilizing small equipment, we maintained a relatively small work area that left the rest of the plant undisturbed during the piling procedure.
The Atofina Plant was expanding and needed to place a series of pipeline racks in an existing pipe rack field. The nature of the piping created compression and tension forces on the columns. Since the plant had several unknown underground pipe chases and had possible contaminated soils, excavation for traditional footing systems was not an option. United Dynamics, Inc. installed helical micropiles to support the columns. The small equipment used to install the helical micropiles enabled our crew to maneuver freely in between the different runs of pipes without posing a danger to the plant or its employees. The micropiles were installed in one day, allowing us to turn over the site to the owner promptly.
North American Stainless
One of N.A.S. scale pits was due for an upgrade. A larger scoop lift was needed to clean out the pit. To accommodate this larger scoop, new foundation pad mounts were installed. In total our crew installed 19 helical piles to serve in both tension and compression. Helicals were selected because of the ease of installation at the site and since the risk of contaminated soils created during traditional auger-cast or caisson procedure is non-existent when working with helicals. Once installed, simple pile caps were created around the helical piles to mount the scoop points.
Boone County Jail
The jail was nine years old and experiencing significant settlement in several areas of the high security facility. It was determined the “engineered fill” had settled as much as 6” in some areas. United Dynamics, Inc. installed helical piers beneath the existing slabs to provide support and raise them to the original elevation. We then placed grout beneath the slab to fill the potential voids created during the lifting process. In the areas where the integrity of the slab was severely compromised, it was removed and replaced. Our crew then installed new construction helical piles to support the slab atop the “engineered fill”. In total, we installed 63 helical piles in close coordination with jail personnel, causing little disturbance to the inmates or daily operations.
Tiebacks can be used for construction or repair projects ranging from simple foundation walls to complex retaining wall systems. United Dynamics, Inc. utilizes special equipment for the installation of these ground anchors. Once the desired depth or embedment is achieved, different types of lock-off hardware are used to create a fixed point along the given structure.
ORA Retaining Wall
The owners of the Owensboro Riverport began to notice a bulge in a 30 year old earth retention wall. Upon investigation, it was determined the ammonia nitrate fertilizer off loaded at the port had slowly eaten away the galvanized straps holding back the panels. United Dynamics, Inc. was called in to install grouted anchors to tieback the affected panels. A total of fifteen grouted anchors were installed to a penetration length of 35’. Long term monitoring of the wall is taking place to determine if any future anchors will be needed in other areas of the wall.
Green River Road – Lloyd Expressway Interchange
United Dynamics, Inc was contracted to install helical tiebacks through a sheet pile wall to facilitate the widening of the Green River Road overpass in Evansville, IN. During the course of the project, it became apparent the soil characteristics had changed in part because of the vibratory hammer used to install the sheet piling. A total of 84 helical tiebacks were installed into the sands beneath the roadway allowing for traffic to be uninterrupted. Each tieback anchor was individually proof tested to verify the load capacities and tension the wall system.