Deep Foundation Records Reflect Groundbreaking Progress
Deepest driven offshore pile foundation. 155 meters below the seabed. 2008. The Tombua and Landana oil fields are located 80 km off the coast of Angola�s Cabinda Province. Oil production is operated by the Cabinda Gulf Oil Company Ltd., a subsidiary of Chevron, with Angolan, French and Italian partners. To exploit the field, the company built the Tombua Landana platform, a compliant piled tower (CPT). Located in 370 m of water, the platform is 474 m tall and weighs 56,400 tonnes. (The Empire State Building is 443 meters tall, to the tip of it�s spire.) It was the fourth CPT in the world at the time of installation. Daewoo Shipbuilding & Marine Engineering was awarded a $1.27 billion contract to build the four-legged platform. Heerema Marine Contractors fabricated the platform�s base structure and foundation piles. The base structure was transported to the site by the semi submersible crane vessel Thialf, the largest crane vessel in the world. In 2008 the base was anchored to the seafloor by 12 skirt piles, inserted through sleeves at the base of the platform. The foundation piles were steel pipe piles 2.7 m in dia, and 190 m long, and driven 155 m below the seabed. The piles were driven by two Menck MHU-2100iS hydraulic underwater hammers, which struck a total of 59,000 blows. The platform contains accommodations for 120 workers. Oil production began in September 2009. The overall construction cost of the platform, the two manifolds (pipes and valves for transferring oil and gas from the wellheads to the pipelines), the 26 km-long oil export pipeline and the 31 km-long gas export pipeline was $3.8 billion.
Heerema
Longest driven precast concrete pile. 270 feet. 1977-78. The Syracuse Metropolitan Sewage Treatment Plant underwent an upgrade in 1977-78, during which secondary treatment systems were added. Slattery Inc. (which is now Skanska USA Civil) was the general contractor. Their subsidiary, Underpinning and Foundation Co., was the pile driving contractor. The piles extended through a thin layer of loose fine sand and then through normally consolidated soft to medium stiff to stiff moderately sensitive varved clay about 180 ft. thick, says Hugh S. Lacey, the project manager for Mueser Rutledge Consulting Engineers for the design of the plant�s foundations. Where the sand was thickest it was possible to found the piles at this level. Many of the piles punched through this layer into a silt that was sensitive to disturbance and penetrated into a lower sand. The artesian water pressure in the lower sand was 10 or more feet above grade or more than 20 ft. above the subgrade from where the piles were driven. As a result the pile driving caused pore water pressures temporarily around the pile tip to liquefy the sands as the piles penetrated into the sand. As a result, it was necessary to re-drive all piles to evaluate pile capacity. Dynamic monitoring was used extensively as a guide to evaluate pile capacity and to test for pile breakage. Several pile load tests were performed using strain monitoring to determine how much load was being transferred to the bearing stratum in this project where over 1 million lineal feet of piling was driven. 14-inch square precast concrete piles were used, and were spliced at 90-foot intervals. A total of approximately 4,000 piles were driven, to an average depth of 250 feet.
Onondaga County Department of Water Environment Protection
Longest barrettes and deepest building foundation. 130 meters. 1993. The Petronas Towers are 452-meter tall twin skyscrapers in Kuala Lumpur, Malaysia. Designed by architect Cesar Pelli, they were the world�s tallest buildings from 1998 to 2004. The geologic profile at the site consists of 12 to 20 meters of silty and clayey alluvial sand, underlain by a medium dense to extremely dense, sandy and gravelly silt and clay material, a residual soil and weathered rock deposit. Below that formation is bedrock � mainly calcitic and dolomitic limestone and marble, located 80 to 90 meters below grade. By varying pile lengths, we at least make settlement more uniform, said Clyde N. Baker Jr., a geotechnical engineer with Soil Testing Services Consultants Ltd. who consulted on the foundation design (ENR 1/15/96 p.41). The foundation contractor was a joint venture of Dragages et Travaux Publics and Bachy Soletanche, with local First Nationwide Engineering Sdn. Bhd. The contractor decided to have the number of bored piles by switching to larger rectilinear barrettes, which constituted value engineering, according to Baker. Each tower has 85 barrettes, and bustles bear on 19 shorter ones. The barrettes are each 1.2 meters x 2.8 meters in section. Three heavy vertical borers shipped in from France bored the holes and filled them with bentonite slurry, after which workers lowered in rebar cages and poured concrete from tubes, forcing grout into the surrounding soil to enhance skin friction. Barrettes were not so much of a problem, except the soil was very aggressive and we had to replace tools many times, said Yap Tek Fui, Bachy�s managing director (ENR 1/15/96 p.50). And silt in the ground...mixed with the bentonite and slowed the whole process. The 208 barrettes support two 13,500 cubic meter foundation mats, each 4.6 meters thick and weighing 32,500 tonnes.
Soletanche Bachy
Longest driven steel pipe pile, and longest land pile. 659 feet. 1999. The Lake Bosse Bridge is a 700 ft-long, four-lane, low level bridge carrying Maitland Blvd. (State Route 414) over Lake Bosse in Orlando, Florida. Central Florida is characterized by karst topography, and Lake Bosse was formed by ancient sinkhole activity. Subsurface conditions below the lake bottom include relic sinkholes filled with deep organic soil deposits and limestone voids. These presented challenges for the bridge building team. The bridge consists of seven bents and a total of 142 piles. Steel pipe piles were selected for ease of splicing and were considered preferable to H piles since they provided better toe resistance due to their greater toe area. The pipe piles were 20-inch diameter, 1/2-inch thick, and spiral-welded. The exploratory borings performed by the Florida Dept. of Transportation went 300 feet deep but did not detect deeper pockets. The estimated pile tip elevation (or average pile depth) for the project was 185 feet, but in some areas the pilings had to be driven much deeper because the subsurface was so inconsistent from what the borings showed, says Wayne Waters, President of Ed Waters & Sons Contracting Co., the piling subcontractor, and senior project manager on the project. We used a spud with a vibratory hammer to look for obstructions before the pilings were driven. Using an APE D-46 pile driver, the Waters crew drove 60 ft sections. One of the piles supporting Pier 2 was driven to 658.56 feet, something not expected at all. Whereas the original bid quantity of piling called for 24,397 linear feet of piling, the job ultimately consumed 36,547 feet of piling, and led to a cost overrun. Fortunately, we provided the owner a unit price for splices and for additional footage at the time of bid. Those unit prices were included in our contract, so the pay quantities were adjusted for the overrun and were were paid accordingly. The result was that due to this compensation for the longer piles and splices, the bottom line remained about the same for us, without loss, says Waters.
Ed Waters & Sons Contracting Co.
The micropiles at the Toyo Tire Plant were 7 and 5/8-inch outer diameter, 1/2-inch thick steel pipe piles.
Hayward Baker
Largest belled caisson dug mechanically. 27 foot diameter. 1972. Water Tower Place is a 74-story building in Chicago, that was the tallest reinforced concrete building in the world (859 feet) when it was completed in 1975. It was designed by Edward D. Dart of Loebl Schlossman Bennett and Dart. The soil profile at the site was 10 feet of urban fill, 20 feet of beach sand, 40 feet of soft clay, 20 feet of stiff clay, then hardpan (dense glacial till) at 90 feet, with bedrock at 140 feet. Chicago is underlain by a thick deposit of soft clay, which is not good for support of tall buildings, explains Bob Schock, president of Case Foundation Co., the foundation contractor for Water Tower Place. The clay gets stiffer with depth, and then at about 85 feet the �Chicago Hardpan� is found -� a dense glacial till, ideal for supporting high loads. The capacity of a drilled shaft sitting on the hardpan can be increased by up to 900% by excavating a bell at the base of the shaft �- such a bell will be typically three times the diameter of the shaft, enlarging the bearing surface by a factor of nine. Case used a large crane-mounted drill rig, and a 10-foot diameter auger to drill the shaft to hardpan. They then used a large Apex belling bucket, with the belling bucket closed, and with wings extended to form a triangular shape, to excavate a 27-foot diameter bell-shaped chamber at the base of the shaft. Then bottom men were lowered into the chamber and did the final cleanout of loose spoil with shovels. Finally a reinforcing cage was lowered into the shaft, and the concrete was poured, by freefall. This was not the largest belled caisson ever. That achievement belongs to an elliptically-shaped bell measuring 19 feet x 33 feet, that was hand dug in the 1950's by Case for the North West Expressway in Chicago.
Case Foundation Co.
On the Lake Bosse Bridge project, unexpected subsurface conditions resulted in the crew driving 50 percent more pilings than the contractor's bid called for.
Ed Waters & Sons Contracting Co.
Longest bored, concrete piles (drilled shafts). 105 meters. 2013. The Kingdom Tower is a skyscraper currently under construction in Jeddah, Saudi Arabia, that will be the world�s tallest building when completed in 2019. The design is by Adrian Smith of Adrian Smith + Gordon Gill Architecture. It is expected to be 1,000 meters high, although the exact height is not being announced by the owner. Kingdom Tower will be mixed-use, containing offices, apartments, a hotel, retail, and an observation deck. The estimated construction cost is $1.23 billion. The Saudi Binladin Group is serving as the project�s general contractor, as well as a partner in the developer, the Jeddah Economic Co. Saudi Bauer Foundation Contractors are the foundation subcontractors. The Tower will sit on a Y-shaped podium founded on a pile foundation built by Bauer. The foundation has to manage the settlement mainly resulting from the 900,000 ton building weight, plus dynamic wind forces, in partially poor soils underlain by porous coral limestone formations, says Bauer. The goal is to make the settlement as uniform as possible. Bauer installed 270 bored piles, some of 1.5 meter diameter and some of 1.8 meter diameter, at four depths � 45 meters, 65 meters, 85 meters, and 105 meters. Seventy two of the 1.5 meter diameter piles were installed at a depth of 105 meters, under polymer slurry support. The long piles were drilled with a specially designed Bauer Group 40 rig equipped with a 5 times 110 m friction Kelly (five times indicates that the rig consists of five single telescopic Kelly bars). The crew had to overcome frequent losses of drilling fluid, unstable cohesionless sand layers in depths of 70, 90 and 100 meters, and corrosive brackish water. Pile installation was performed from December 2012 to December 2013.
Bauer Group
The auger, loaded with clay.
Case Foundation Co.
The Petronas Towers each rest on 32,500-tonne foundation mats, supported by 104 barrettes.
Soletanche Bachy
Largest diameter steel pipe piles. 72 feet diameter. 2011. The Hong Kong-Zhuhai-Macau Link is a 50km set of bridges and tunnels across the Pearl River estuary, that is expected to spur greater economic development, in a region that is already one of China's most dynamic. The $10 billion project will include 23 km of bridge structures, and a 6.7 km long immersed-tube tunnel, the world's longest, under the Lantau Channel, one of the world's busiest shipping channels. The project�s prime contractor is China Communications Construction Co. Ltd. (CCCC). Two artificial islands had to be built, to serve as entry and exit points for the tunnel mouths. In 2009 several Chinese government design organizations decided that driving large diameter steel caissons to form the artificial islands would shave more than two years of construction time off the original plan to use sheet piles. They contacted American Piledriving Equipment, a firm with experience in China driving very large diameter piles, to find out if driving larger piles than ever before was possible. APE decided the proposed plan was technically possible, and was hired in 2011. The piles were 73 ft in diameter, 1 inch thick, 130 ft tall, and weighed 665 tons each, including internal braces. The monster cylinders were fabricated by Shanghai Zhenhua Heavy Industries. APE devised a $20 million system of eight linked vibratory hammers that had to operate in perfect sync, known as the Octakong. The Octakong required 9,600 horsepower and delivered 4,000 tons of force. Huge challenges were involved, explains David White, managing director for APE China. The soil on the first island near Macau had N-value 27 sand, which made driving fairly smooth. The second island near Hong Kong, however, had much more complex soil conditions. Oftentimes N-value 15 sand was on one side of the pile and N-value 40 was on the other. Essentially the pile was so big that we were driving through two different soil conditions at once. When using vibratory hammers the frequency of the hammer can be changed on the fly to better match the soil condition. However in our case we were not able to find a frequency that satisfied the two soil conditions that were being penetrated at the same time. Many hours of meetings and strategy thinking were involved to figure out how to drive the pile straight in the ground, due to the fact that the pile would lean in the direction of the softer soil. When completed in December, 2011 the 120 piles formed bulkheads that created two artificial islands, each 625 m long, 160 m wide, and 30 acres in area. The immersed-tube tunnel is currently under construction, and the Link is expected to open in 2016.
CCCC
Case used a Bauer Group 40 drilling rig with a mast extension kit to install the 48-inch diameter, 100-foot long piles.
Case Foundation Co.
Increasing project complexity and machinery improvements have enabled engineers to create deeper, stronger foundations for buildings and infrastructure.
Photo by Tudor Van Hampton for ENR
Largest augercast pile by volume. 62 cubic yards. 2012. River City Casino is located in Lemay, Missouri, on the west bank of the Mississippi River. The owner, Pinnacle Entertainment Inc. subsequently decided to build an additional five-story, 1,600-space parking garage to serve the casino. The subsurface conditions consisted of successive layers of fill, soft clay, sand, stiff clay, and rock. Case Foundation, the pile driving contractor, used a Bauer Group 40 drilling rig with a mast extension kit to install 92 18-inch diameter augercast piles weighing 200 tons each, and 41 48-inch diameter, 100-foot long augercast piles weighing 1,000 tons each. Approximately 62 cyd of 7,000 psi grout was used per pile, explains Eric J. Risberg, vice president of Case Foundation. The only special challenge that we had to tackle was the ability to keep that volume of grout supplied to our pump to install eight piles per day.
Case Foundation Co.
Longest composite (or hybrid) piles. 260 feet. 2006. Hudson River Park. This four mile long park extends along the western shore of Manhattan, providing lounging areas and paths for runners and bikers. The Chelsea Cove area of the park features three piers. Pier 64 extends 500 feet out into the river, and is topped with 1.1-acres of lawn. Weeks Marine Inc., the pile driving contractor, drove some piles that consisted of precast prestressed concrete piles in the upper section spliced on to HP 14x48 steel H-pile in the lower section. The concrete sections of these longer piles were 24 inches x 24 inches x 80 feet long, with lower sections that were as long as 180 feet, for a maximum length of 260 feet. According to Jesse Ottesen, Chief Estimator at Weeks Marine, we used two cranes; the Weeks 535, which is a Clyde Model 28 Gantry Crane, and the Weeks 572 which is a Model 28 Dravo, a barge mounted crane.
Mueser Rutledge
Longest micropile. 295 feet. 2005. Toyo Tire and Rubber Co. built it�s first North American tire manufacturing plant in White, Georgia in 2005. Mactec/Amec was the geotechnical engineer for the project, and James N. Gray Co. was the general contractor. Initial plans called for a drilled shaft foundation. But while the shafts were under construction, it was discovered that an extremely deep slot of solutioned limestone existed on site, trending northeast to southwest across the very large building footprint, says John Wolosick, a director at Hayward Baker, and the engineer of record for the micropiles. Hayward Baker designed and installed the micropiles. Drilling for the shafts indicated that this slot was more than 150 feet deep, and filled with soft clay. The drilled shaft contractor, McKinney, could not drill any deeper than about 150 feet, especially in the weathered limestone. So they were at their limit. The micropile system was needed because the foundations had to go deeper. This is the most economical system for such great depths in weathered limestone with clay-filled voids. So micropiles were used within the deeply weathered slot. Drilling was done using a concentric duplex down-the-hole hammer system. The micropiles were 7 and 5/8-inch outer diameter, 1/2-inch thick steel pipe piles, and were installed using a Casagrande drill rig. After being drilled into the limestone, the piles were fully cement grouted. Pile lengths were extremely variable, with the shorter piles in the 65 to 85 foot range. However, in the deep slot area, single pile lengths increased dramatically, with three piles extending to 235 feet, 265 feet, and 295 feet. Micropiles are cement grouted steel pipe piles that are less than 300 mm or 12 inches outer diameter.
Hayward Baker
The record-setting pile.
Ed Waters & Sons Contracting Co.
Engineers favor deep foundations when there are very large design loads, poor soil at shallow depth or site constraints, such as adjacent structures. Many deep foundations are put in place by driven piles or drilled shafts. And most foundation contractors tend to specialize in one method or the other.
"I grew up in a pile-driving family," says Mike Wysockey, president of Thatcher Foundations Inc., Gary, Ind. "My father took over the firm, which was founded in 1946, in the early 1970s." The pile-driving "market in general has been picking up some, with bigger firms trying to muscle into the deep foundation market. Firms are chasing the work really hard."
Thatcher performs mostly building work, as well as sheet piles for retaining walls and dock walls. Its main competitors are Case Foundation and Hayward Baker, both owned by the Keller Group.
One recent development that Wysockey has seen is the introduction of "bigger new H-pile sections. They used to be 14 inches. Now they make 16-in. and 18-in. H-pile that can hold more load. They can support a bigger hammer. In some ways it's easier to drive bigger piles. Bigger, stiff beams are a conduit of energy."
Van Hogan, director of development at the Pile Driving Contractors Association, agrees with that view, commenting that "contractors are driving larger piles that require bigger hammers, and are trying to get higher capacities out of these piles." He points towards improvements in equipment, as well.
"Hammers have made improvements, taking great steps to reduce emissions. Hydraulic hammers are much improved, better insulated, creating far less noise," he explains. Some hammers now "have a long drive cap extended so it fits down several feet over a pile, so you don't have to have leads," or vertical beams that guide the hammer and the pile. "
High-frequency variable moment hammers "have become more common in the last five years," Wysockey adds. "They've really taken over in the urban market. Their vibratory energy is less damaging to adjacent structures."
Drilled shafts, or caissons, also have gradually evolved. Bob Schock, president of Case Foundation Co., based in Roselle, Illinois, has devoted almost four decades to the drilled-shaft side of the market. "I joined geotechnical engineering firm Soil Testing Services as a technician, then joined Caisson Corp. in the early 1980s as the hand-dug caisson era was fading and becoming a mechanized process. Caisson was acquired by Case in 1983."
The firm's specialty "is drilled heavy foundations, usually installed in clusters for tall buildings," says Schock. "We did 7 World Trade Center [New York], the John Hancock Center [Chicago], and the Sears Tower [Chicago] all on large-diameter drilled caissons. We do bridges. We also do foundations for electrical transmission line towers and electrified rail lines."
The drilled shaft industry "blossomed" in the 1950s and 60s with the development of larger diameter drills, Schock notes.
"Case has been a pioneer in a lot of ways, such as excavated rock sockets. Originally they were excavated by hand, then by coring tools, and now by high-pressure air hammers. We've been at the forefront of augercast piles over the past 10 or 12 years. We do them up to 48 in. diameter. The stem of the auger is hollow. You pump high-strength grout through the stem. You're casting a pile in the ground. It's an outgrowth of the drilled shaft industry."
In addition to many firms active across the world, the wide scope of the foundation market is reflected by the existence of the three major professional associations, the Pile Driving Contractors Association, the Association of Drilled Shaft Contractors, and the Deep Foundation Institute, which includes firms from both the pile driving and drilled shaft sectors.
Even so, there is no central information source for this specialized business. While ENR has attempted to dig up the greatest examples of various deep foundation jobs in our slideshow, this list is not comprehensive. We urge readers to contact us with other records for consideration.
