Where We've Been

Washington - Private Work

Amazon Blocks 26, 32, 34, and 35

Location: Seattle, WA

General Contractor: GLY (Blocks 34 & 35), Sellen Construction (Blocks 26 & 32)

Details: On the two blocks bounded by Mercer and Republican Streets and Terry and Fairview Avenues, DBM constructed both earth-retention and deep-well dewatering. The contract required the design and installation of 318 soldier piles, 574 tieback anchors and approximately 62,000 square feet of timber lagging. The dewatering wells were installed to a depth of 50- to-60 feet, which provided lowering of the ground water table by up to 28 feet from its initial level to allow completion of the mass excavation and building foundations.

On the block bounded by Terry Avenue and Boren Street, DBM installed the earth-retention system for the 12-story building with six levels of underground parking. The job required installation of 141 soldier piles, 784 tieback anchors and approximately 60,000 square feet of lagging. The unlevel site presented a number of challenges, including the variable number of tieback rows which ranged from three to eight rows. Twenty-five of the up to 90-foot-long piles provided underpinning support for existing foundations of an adjacent historical brick building that is being used during the construction phases. Even with the challenges, the earth retention was completed weeks ahead of schedule.

Good Samaritan Hospital

Location: Puyallup, WA

Owner: Good Samaritan Hospital

General Contractor: Skanska

Details: DBM completed a $3.7 million contract to build 30,000 square feet of soil nail earth retention with permanent shotcrete facing and installed 24,000 square feet of temporary soldier pile excavation support walls for the 9-story Patient Care Tower and supporting structures at MultiCare Good Samaritan Hospital in Puyallup. DBM’s portion of the project included installing approximately 900 soil nails totaling 26,000 lineal feet, 180 soldier piles totaling 5,400 lineal feet and 95 tiebacks totaling 3,400 lineal feet.

The completed facility houses 80 family-friendly private rooms, a new emergency department, state-of-the-art surgical suites, diagnostic imaging center, medical office building and a parking garage.

2020 5th Ave

Location: Seattle, WA

Owner: Lydig Construction

General Contractor: 2020 5th Ave. LLC

Details: The renovation of the two-story office building required innovative foundation design and construction concepts to achieve current City building codes and construction schedules. The renovation required demolition of the two above street level floors as well as below grade parking then building six new floors. Micropiles and soil nails proved to be key design and construction solutions for foundation support of the resulting new building structure, underpinning support of existing columns and walls remaining in place and temporary excavation support for construction of the additional below grade parking structure.

The project required DBM to install approximately 3,500 square feet of soil nail and shotcrete temporary shoring, 133-each micropiles ranging from approximately 39 foot to 54 foot depths, and temporary steel structures to support load bearing walls and columns that were underpinned to facilitate the installation of new walls and columns below. The work was performed inside the existing building, and required the use of tight access drill rigs.

Providence Sacred Heart

Location: Spokane, WA

General Contractor: Bouten Construction

Details: As part of an addition to the Providence Sacred Heart Hospital Emergency Room, DBM Contractors, Inc. recently completed installing 64 each micropile foundations. Due to the highly variable ground conditions, the micropile design and installation methods needed to be flexible to account for the conditions encountered in the field at each micropile location. Micropiles were six inches in diameter, ranged in depth from 35 feet to 45 feet and supported loads of up to 100 kips in compression and 20 kips in tension. The emergency room expansion will include 24,000 new square feet and the remodeling of more than 4,200 square feet of existing space.

Washington - Public Work

Manette Bridge

Location: Bremerton, WA

Owner: Washington State Department of Transportation

General Contractor: Manson / Mowat JV

Details: The Manette Bridge replacement required DBM to install 16 each 12-foot diameter drilled shafts up to 145 feet deep and totaling approximately 4,900 cubic yards of shaft excavation and approximately 5,700 cubic yards of shaft concrete. For 12 of the shafts access could only be provided via work barge by way of the Puget Sound waters. The remaining four shafts were constructed landside.

The existing bridge was not rated for the combined weights of ready-mix concrete trucks and a pump truck. In order to deliver concrete to the in-water shafts DBM utilized a two concrete pump truck delivery system. The system involved pushing concrete through approximately 1,000 lineal feet of slick line using one of the pump trucks located landside before reaching a second pump truck located waterside near the top of the shaft location, where concrete was placed into the drilled shaft excavation.

Green River Bridge

Location: Black Diamond/Enumclaw, WA

Owner: WSDOT

General Contractor: Scarsella Brothers

Details: The Green River Bridge on state Route 169 between Black Diamond and Enumclaw was span was closed in November 2008 due to unstable soil at the south approach. It took about $8 million and two phases of repairs to make the bridge safe for traffic. The first phase started in June of 2008, when engineers noticed significant soil movement. DBM Contractors installed 90 soil nails and covered the area with shotcrete as part of the interim, low-impact repair.

Heavy rains in November caused further soil movement, prompting WSDOT to close the bridge and do permanent repairs. To fix the slide problem, DBM built a 160-foot-long retaining wall that reaches as much as 90 feet down into firm bedrock. DBM drilled 57 shafts, which were filled alternately with concrete and lean concrete, and nailed the wall into the ground.

Brightwater Freeze Holes

Location: Kenmore, WA


General Contractor:

Details: Working closely with SoilFreeze of Seattle, WA, DBM installed a ground freezing program designed to rescue a disabled tunnel boring machine(TBM) at the Brightwater Conveyance System. This project is the deepest "zone freeze" project (targeted freeze from 280' to 330' below ground surface) known to be completed in the United States.

To complete the complicated project involving a variety of soil conditions and the restricted location of the operation, DBM drilled 35 holes up to 330-feet deep and installed five-inch steel freeze-pipes for the full depth of each hole. Borehole advancement included a combination of 9 5/8”-diameter permanent steel casing, and a combination of rotary drilling with air and water flushing media to achieve the 330-foot-depth. Bentonite drilling fluid was used to maintain borehole stability while the freeze pipes were installed.

WSDOT Nalley Valley

Location: Tacoma, WA

Owner: WSDOT

General Contractor:

Details: Installation of 84 each drilled shafts for support of new freeway bridges. Shaft excavations vary in diameter from 6' to 14', with primary diameter range of 8' to 10'. Shaft depths extended to a maximum of 105', with an average depth of 65'.

Soos Creek

Location: Covington, WA

Owner: Soos Creek Water Development

General Contractor:

Details: Install 21,000 lf of 1 m diameter secant pile excavation support : Secant piles provided shoring for 20' dia to 40' dia shafts and ranged from 65 feet to 80 feet in depth with 6500+ cy of concrete placment. Includes installation of concrete guide wall system to maintain secant pile alignment.

Oregon - Public Work

Port of Newport Phase I&II

Location: Newport, OR

Owner: Port of Newport

General Contractor: Natt McDougall Co. Tualatin, OR

Details: DBM installed 55 each 200 kip capacity permanent ground anchors to support a 180 foot long section of sheet pile bulkhead. Anchors were drilled from access on the deck of the scuttled concrete ship, the Pasley, which was listing at about a 15 degree angle – a significant challenge for crews to set up equipment and install the anchors.

Willamette River Bridge

Location: Eugene, OR

Owner: Oregon State Department of Transportation

General Contractor: Hamilton Construction

Details: Completed installation of permanent cantilever piles and drilled shafts for earth retention and foundation support for the Willamette River Bridge between Eugene and Springfield, Oregon. The project involved the installation of 48-each steel soldier piles at Wall 21128 and 55-each steel soldier piles at Wall 21129. Additionally, DBM installedl 22 each, seven-foot and eight-foot diameter drilled shafts ranging in depth from 30 feet to 80 feet.

Alaska - Public Work

Seward Highway

Location: Seward, AK

Owner: Alaska Department of Transportation

General Contractor: Hamilton Construction

Details: DBM completed foundation support and drilled shafts for a section of Seward Highway. For this phase of the project DBM completed 10 each two-foot and four-foot diameter drilled shafts ranging in depth from 24 feet to 95 feet.

Idaho - Public Work

Parkside Condos

Location: Coeur d'Alene, ID

Owner: Parkside Towers, LLC

General Contractor: Robert Goebel Construction

Details: Temporary excavation support system consisting of 107 each soldier piles, 221 tiebacks, and 23,550 sq. ft. timber lagging. Also installed 16 each micropiles for the support of a tower crane foundation.

California - Private Work

Lone Bluff

Location: San Diego, CA

Owner: Newland Communities

Details: DBM completed a slope stabilization project in an occupied San Diego neighborhood on Lone Bluff Way.. The project was completed during the winter months on an actively creeping slope with a gradient of 2H:1V. The stabilization is intended to secure the slope safely for both homes located above the top of the slope as well as homes located adjacent to the bottom of the slope. There were homes above the construction that were vacated until completion of the stabilization but the homes at the base of the slope remained occupied requiring extra safety precautions.

To complete the project DBM drilled and installed 146 each permanent tieback anchors requiring more than 15,000 lineal feet of tieback drilling, arranged in up to four rows of varying elevation on the slope. Each of the tieback anchors was tested and locked off at the design load of 246 kips. The anchors were installed through a 5.5 foot tall and 3 foot thick, 1,255 total lineal feet of reinforced shotcrete grade beam. DBM also completed grading to restore the slope upon completion of the installation.

California - Public Work

University House

Location: La Jolla, CA

Owner: University of California at San Diego

Details: Working as the prime contractor, DBM completed installation of a permanent shoring system for the Chancellor’s House at University of California San Diego a first step in rehabbing the historic University House. Sitting on a La Jolla Bluff and atop a Native American burial ground, the house has been vacant since 2004.

The shoring system required DBM to install 11 each solider piles and 1,054 square feet of permanent sculpted shotcrete facing for the 11,400-square-foot adobe house. Due to the cultural considerations DBM took great care to not affect the ground outside of the general work area. The geology comprising the bluff is a sandstone material. The upper soil, above the sandstone, is comprised of material where there have been numerous discoveries of Native American remains over the years that date back in excess of 5,000 years. The state Native American Heritage Commission has declared the property a sacred Indian burial site. Thus the upper soil was excavated by hand by the project archaeologist under the supervision of Native American monitor.

Harris Reservoir

Location: Thousand Oaks, CA

General Contractor: Spiess Construction Company

Details: The Harris Reservoir was experiencing significant structural distress related to unstable soil conditions in the hillside where the reservoir is located. The project included demolishing the existing tank and building the new tank within the existing tank footprint. The new tank is smaller in diameter but is extended to nearly 50 feet deep to provide the same 4,000,000 gallon capacity.

In the first phase, DBM installed a reinforced shotcrete compression ring earth retention system. The shotcrete ring supported a 27 foot deep excavation below the foundation of the existing tank, allowing construction of the new tank. To complete the compression ring, DBM installed 11,000 square feet of reinforced shotcrete. To provide additional foundation stability in phase two, DBM installed 91 each, 290 kip permanent soil anchors through the foundation of the new tank and into the underlying slope.

Arizona - Public Work

Banjo Bill

Location: Sedona, AZ

Owner: Arizona Department of Transportation

Details: DBM earned the Arizona Transportation Excellence Award in 2008 for its $7.5 million rockfall containment project in the Oak Creek Canyon, six miles north of Sedona, Arizona. The Arizona Department of Transportation (ADOT) contracted with DBM for the project known as the Banjo Bill Rockfall Containment Project to repair 350 feet of the roadway, a site of dangerous rockfall and debris flow down the steep slopes of the canyon following the natural draws eroded into the canyon slope. The project included installing two 90-foot-long by 30-foot-high retaining walls at the bottom of the eroded channels and creating a basin to catch and contain the falling rocks.

To anchor the wall system, DBM placed 136-each micropiles to a depth of 48 feet with four rows of permanent tieback anchors. The micropiles, which acted as the wall vertical structural elements, were installed at a 16-inch on center spacing and were laterally supported by an anchored shotcrete facing.

Nevada - Private Work

The Cosmo

Location: Las Vegas, NV


General Contractor:


River Palms

Location: Laughlin, NV


General Contractor:


Mission Industries

Location: Las Vegas, NV


General Contractor:


Colorado - Public Work

Telluride Regional Airport

Location: Telluride, CO

Owner: Telluride Regional Airport

General Contractor: Williams Construction

Details:DBM Contractors, Inc. worked to structurally stabilize a landslide near the southeast end of the runway at Telluride Regional Airport, North America's highest commercial airport. Since the mid-1980’s the airport has been plagued by landslides resulting in damage to property and threatening the airport operations. The landslide extended from the outer edge of the upper flat mesa area where the airport runway is located.

As work progressed down the hillside benches were cut for the subsequent levels of tieback anchors. Due to conditions encountered during construction a total of 16 rows of tieback anchors were installed with a total quantity of 371 each tieback anchors. In total there were more than 35,000 lineal feet of tieback ground anchors drilled and installed at the site.

The tieback anchor installation included drilling 6-inch diameter holes for the tieback tendon installation. The tieback anchors included either 141 kip or 211 kip tieback anchors with 326 each of the anchors having a design load of 211 kips. Each of the tieback anchors was backfilled with a neat cement grout.

Montana - Public Work

Two Medicine Bridge

Location: East Glacier, MT

Owner: Montana Department of Transportation.

General Contractor: Ralph L. Wadsworth Construction Company LLC out of Draper, Utah

Details: DBM installed foundation support for the Two Medicine Bridge on the Blackfeet Indian reservation near East Glacier, Montana. The project required DBM to install 18 drilled shafts into shale bedrock. Ten of the shafts were six feet in diameter with an average depth of 30 feet and eight were eight feet in diameter with a depth of 79 feet. The fast track project had to be completed in two months to avoid winter weather conditions. Two Medicine River Bridge project will replace the existing bridge over Two Medicine River on US Highway 2 (US 2) on a new alignment with approximately one mile of new roadway. The work replaced an existing bridge, built in 1941.

Belfry North

Location: Helena, MT

Owner: Montana Department of Transportation

General Contractor: Tamietti Construction Co., Inc.

Details: DBM Contractors, Inc. completed the foundation support for a bridge just north of Belfry, Mont. on State Route 72. The bridge replacement project, completed during the cold winter months, required DBM to install 200 feet of 4 foot diameter drilled shafts.

Utah - Public Work

SR 189 Vivian Park

Location: Orem, UT

Owner: Utah DOT

General Contractor: UDOT

Details: 175,000 SF of permanent sculpted shotcrete to cover existing anchored walls along a roadway. Walls were up to 100' high. All shotcrete was sculpted and stained. Some new rock bolts were installed for added support to the shotcrete. Aesthetic appearance of shotcrete facing was design build, and was subject to approval from a project shareholders group. DBM was GC for the project.

Hawaii - Public Work

Hawaii H1 and H3 retrofit

Location: Oahu, HI

Owner: Hawaii Department of Transportation

General Contractor: Kiewit Pacific

Details: The H1 and H3 retrofit on Oahu required DBM to install 17 each 48” diameter by 75’ average depth and 38 each 60” diameter x 104’ average depth shafts. They also used polymer slurry with sockets installed into the basalt bedrock. Kiewit Pacific was the general contractor for the Hawaii department of Transportation. HDOT was also the designer of the job.