Spring  2016
Going Deep
San Francisco, California

    
    
Malcolm is under contract to provide temporary support of excavation for 500 Folsom in San Francisco, CA a proposed 570 unit apartment building located within the Transbay Development Area south of the Financial District in Downtown San Francisco and has a building height of 440 feet. The project requires 8 floors of below grade parking developed within a 72 feet deep excavation. Due to the steep sloping bedrock a combination of secant piles and CSM panels will be for the temporary shoring walls. The excavation will be braced by a combination of internal struts and tiebacks. The project is underway with demolition of the structure which will be immediately followed by the foundation work.

For more information, please contact John Morgan at jmorgan@malcolmdrilling.com.




Reaching High
Miami, Florida
Malcolm has recently employed some of the largest equipment of its kind to install large diameter, very deep CFA piling in the Southeast. Our new Liebherr LR 1300 crane and Berminghammer's box lead system is a multi-million dollar commitment in Malcolm's investment in that region. This unit will complement our well proven fleet Bauer drilling rigs in the South Florida market and extend the depth for Auger Cast piles beyond 170 ft.

The equipment will debut on CMC's Brickell Flatiron project with 65 story building located in the heart of Miami's most sought after residential community. The foundation for this iconic high rise building consists of 560 Auger Cast Piles, 30-inch in diameter and drilled to 130 feet depth in depth through strata's of limestone, cemented sand and calcareous sandstone.

With our new state of practice high torque leader system Malcolm is position to handle any size and depth Augercast pile project throughout the United States. This project will complement our existing portfolio of large and complex Design-Build projects such as the Port of Miami Tunnel, the Brickell Citi-Centre and the Jade development project.

For more information, please contact Andrew Morog at amorog@malcolmdrilling.com.


Drilling Fast
San Francisco, California
    

The Exchange project south of downtown San Francisco, reflects urban life and the Mission Bay's rapid revitalization. The estimated $485-million development will provide office space in four interconnected buildings with retail space, a lobby bike spa, and rooftop gardens.

The site is located in an area that was once part of a shallow bay reclaimed with fill in the late 1800s and therefore has a very variable geology ranging from layers of loose fill, very soft clays, dense sands and very stiff clays overlying the Franciscan formation. The original design called for a deep foundation system utilizing driven piles to refusal into the Franciscan bedrock. Malcolm won the job by proposing a Design-Build Value Engineering alternate utilizing 3 foot diameter drilled shafts with varying depths. By replacing multiple driven piles and large pile-cap with one drilled shaft per column, we offered substantial savings in both cost and schedule to Kilroy Reality the project developer. One full scale Osterberg Cell load test program verified our preconstruction design assumptions, which allowed us to optimize our final design utilizing the actual load bearing capacity of each soil layer on site. A team of engineers from Dan Brown Associates (designer) and Langan (EOR) is allowing Malcolm to optimize drill depths by logging and analyzing each shaft as it is drilled to determine the required tip elevation.

Production commenced in March, 2016 after 2 weeks of heavy rain thanks to El NiƱo. A total of 308 shafts will have to be installed over 3 months with two crews.

For more information, please contact Tian Yu Dong at tdong@malcolmdrilling.com.

 
Walking on Water
Seattle, Washington

   

Working to construct a bridge in an environmentally sensitive area can be very difficult. The new 2 mile section of State Route 520 is being constructed across the Lake Washington adjacent to the existing highway that acts as the west connection for the largest floating bridge in the world. This section is 90% over water and consists of 99 drilled shafts varying from 8-12 feet in diameter with depth of up to 175 feet.

A containment area was built at each shaft location using multiple layers of a fiber reinforced plastic along with a spoils bin for direct spin off and spoils control. Constant monitoring, inspection, and maintenance were needed to ensure the operations remained contained. Spoils are hauled away in sealed trucks with concrete moving in shortly thereafter.

Polymer drilling slurry was utilized in addition to permanent steel shaft casings in the upper length of the shaft that needed to be piped using high density polyethylene (HDPE) piping and was wrapped with secondary containment in high traffic areas. A group of plumbed slurry tanks followed the operations down the trestle allowing for storage, batching and remixing.

The Malcolm team will complete all shafts by the end of 2016 with traffic running over the new bridge in summer of 2017.

For more information, please contact Adam Running at arunning@malcolmdrilling.com.


Tremie Concrete Guide
         
The Deep Foundations Institute (DFI) and the European Federation of Foundation Contractors (EFFC) have released a free download of the recently published Best Practice Guide to Tremie Concrete for Deep Foundations.

The guide is the result of the initial study efforts of the joint DFI and EFFC Concrete Task Group, which was established in 2014 to study common problems in drilled shafts and diaphragm walls constructed using tremie 
methods.

The primary purpose of the guide is to present design considerations (concrete rheology, mix design, reinforcement detailing, concrete cover, etc.) and best practices for tremie concrete placement for drilled shafts and diaphragm walls that promote construction of high quality elements. In addition, the guide proposes changes to the methods used commonly to specify concrete mixes and the procedures to test them.

It highlights important considerations to minimize risk related to concrete workmanship and quality, and potential conflicts between specialty contractor, designer and supplier.

For more information, please contact Peter Faust at
pfaust@malcolmdrilling.com.