The construction of Berths 55/56 at the Port of Oakland required the stabilization of a cut slope under a proposed container wharf, extending 2,400 feet long and 124 feet wide. The cut slope was constructed to transition soil backlands to the design dredge depth for a maximum slope height of 65 feet.

Soil conditions encountered on the project consisted of surface fill, Bay Mud and Young Bay Deposits described as soft, weak and/or susceptible to seismically induced liquefaction and lateral spreading. This condition posed a potential threat to the stability of the proposed wharf structures during and after major earthquakes. A CDSM buttress system was proposed to provide shoreline stabilization and control lateral spreading.

The soil-cement buttress consisting of a rectangular grid of Cement Deep Soil Mixed (CDSM) walls was formed using 3-foot diameter columns spaced on 2-foot centers. The grid consisted of two longitudinal walls parallel to the shoreline spaced 32 feet apart, and a series of transverse walls perpendicular to the shoreline spaced nine feet apart. The transverse walls served as the primary source of soil stability while the longitudinal walls provide end restraint for the transverse walls and contain the potentially liquefiable fill behind the buttress.

A CDSM test section was performed prior to full production to verify that the CDSM equipment, procedures and mix design could produce the required soil improvement as well as to assess the impact of wharf pile driving on the CDSM walls. Results from the test section demonstrated that the CDSM walls would provide adequate stabilization of the shoreline, satisfying the geometric, strength design and uniformity requirements. The test section also demonstrated that the driving of wharf piles would not adversely affect the CDSM buttress. The use of the CDSM method allowed for the owner to capitalize on noteworthy cost and schedule benefits.

Over 36,000 cubic yards of CDSM ground stabilization was constructed over a period of five months. Triple-shaft CDSM equipment was used for ground stabilization to a maximum depth of 38 feet. Drilling depth, penetration/withdrawal speed, shaft rotation and slurry injection rates were monitored in real-time and recorded in 3-foot depth increments to assure accurate control and a uniformly mixed soil-cement product.

Test specimens for unconfined compressive strength were retrieved by a triple barrel coring system, and exceeded the acceptance criteria of an average 160 psi at 28 days.
 

The construction of Berths 57/58 at the Port of Oakland required the stabilization of a cut slope under a proposed container wharf extending 2,400 feet. The cut slope was constructed to transition soil backlands to the design dredge depth for a maximum slope height of 65 feet.

Soil conditions encountered on the project consisted of surface fill, Bay Mud and Young Bay Deposits described as soft, weak and/or susceptible to seismically induced liquefaction and lateral spreading. This condition posed a potential threat to the stability of the proposed wharf structures during and after major earthquakes. A CDSM buttress system was proposed to provide shoreline stabilization and control lateral spreading.

The soil-cement buttress consisted of a rectangular grid of Cement Deep Soil Mixing (CDSM) walls formed using 3-foot diameter columns spaced on 2-foot centers. In the shallow Bay Mud area, the grid consisted of two longitudinal walls parallel to the shoreline spaced 31 feet apart, and a series of transverse walls perpendicular to the shoreline spaced twelve feet apart. In the deep Bay Mud area, the width of the CDSM grid was increased by extending the transverse walls in the direction of the shoreline slope. When the width of the CDSM grid was greater than 68.5 feet, a third longitudinal wall was added. The maximum treatment depth in the deep Bay Mud area was 88 feet.

Over 60,000 cubic yards of CDSM ground stabilization was constructed over a period of five months. Triple-shaft CDSM equipment with a real-time monitoring system was used for ground stabilization.

Test specimens for unconfined compressive strength were retrieved by a triple barrel coring system, and exceeded the acceptance criteria of an average of 150 psi at 28 days.

The construction of the Oakland International Airport Roadway Project for the airport expansion required the stabilization of subsurface soils for the construction of three grade separation structures - two roadway interchanges and one intersection of a roadway and taxiway serving the airport.

Loose, sandy fill and soft Bay Mud were improved by Cement Deep Soil Mixing (CDSM) for the construction of a soil-cement foundation under MSE (Mechanically Stabilized Earth) walls for a roadway over-crossing, a soil-cement gravity retaining wall to maintain stability of a roadway under-crossing during and after a major earthquake, and a soil-cement-bentonite cutoff wall for groundwater control.

A test section was performed prior to full production to verify that the CDSM equipment, installation procedures, and mix designs would produce soil-cement and soil-cement-bentonite with sufficient strength, uniformity, and permeability to meet the design intent. Additional test sections were performed for the confirmation or modification of the mix design and installation procedures to cope with the complex subsurface soil conditions resulting from the historical development of the site. Test section results revealed that the CDSM cutoff wall, retaining wall, and foundation could be constructed to satisfy the design criteria and that the supplemental test sections would alleviate the impact of the varying subsurface soil conditions.

Over 60,000 cubic yards of CDSM ground improvement and over 8,500 cubic yards of CDSM cutoff wall were constructed over a period of eleven months. xxxx Triple-shaft CDSM equipment was used for ground stabilization and cutoff wall installation to a maximum depth of 43 feet. Drilling depth, penetration/ withdrawal speed, shaft rotation and slurry injection rates were monitored on a real-time basis for accurate mixing control and a uniform mixed product.

Core samples were retrieved from the hardened soil-cement foundation and gravity retaining walls for strength testing. Test specimens from the soil-cement-bentonite cutoff wall for strength and permeability testing were retrieved by wet sampling. Acceptance criteria for unconfined compressive strength required an average of 150 psi at 28 days for ground stabilization and an average of 80 psi at 28 days for the cutoff wall. Hydraulic conductivity of the cutoff wall required a maximum coefficient of 1x10-6 cm/sec.

The CDSM (Cement Deep Soil Mixing) method was used to construct a grid pattern of soil-cement columns under two 820-foot by 490-foot critical industrial facilities.  The grids were created to prevent the generation of excessive pore water during and after earthquakes and to prevent the liquefaction of soils within the foundation area.

Raito was contracted to build a Cut Off Wall for the city of Ensenada, Mexico. 

The world's largest breakwater has been completed in Mexico.  Raito, Inc. helped build the foundation for this 680m breakwater for the Ensenada, Mexico project.