Mark West Quarry Mining and Reclamation Plant
Santa Rosa, CA

Mark West Quarry is one of the primary suppliers of high quality crushed rock aggregate in the North Bay area. The owner plans to expand the quarry in response to the increasing demand for concrete aggregate, aggregate
road base, sub­base, and fill material.  The quarry presently extends over 85 acres. It will be expanded to 184 acres and will be developed as an open pit excavation with working slopes as much as 90 feet high.

The   quarry   expansion  requires   several   governmental permits, a detailed reclamation plan that outlines the planned operations, the expected environmental effects, the final land configuration, and use. These detailed plans require the expertise of numerous professional consultants, such as geologists and geotechnical engineers, hydrologists, environmental planners, biologists, and landscape architects.

The   site   geology   includes   greenstone
rock of the Franciscan Complex, which is
the   resource   formation.  The site also
includes ash fall deposits of the Sonoma
Volcanics and two ancient landslides.
 
The planned quarry operations will lower
the ridge top about 450 feet to the final
quarry floor and will consolidate surface
drainage into a single watershed for erosion control.  

Miller   Pacific   provided   the   baseline
geologic mapping  and geotechnical
engineering for the quarry operations and
reclamation plan.  Our slope stability
analyses established the basis of design
for both interim and final slopes.   The
interim slopes will be 60 to 90 feet high,
as needed for efficient operations, while
the final slopes will have a total vertical
height of 365  feet and will incorporate
wide benches at 30­foot vertical intervals.
Our reclamation recommendations
include criteria for quarry closure fills,
drainage, and the final end use of the
quarried area.  

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Shamrock Center/ 
Landrover Dealership
San Rafael, CA

Client: La Terra Trifoglio
Architect: Patri Marker Architects

This new development was a reuse of former ready mix concrete plant. The site is a former
marshland that had been filled progressively over several decades with random rock and
concrete tailings. Development required the site to be raised about four feet for flood protection and was to incorporate portions of an existing masonry building. Grade transitions and control of differential settlement was paramount.

After a thorough subsurface exploration
and analysis, MPEG developed a unique
solution to avoid differential settlement.
The existing building was modified with a
false floor to avoid placing new fill that
would induce new settlement. To prepare
the new building area the existing fill was
over excavated and the area backfilled
with extremely lightweight “concrete” fill to
achieve “zero” stress increase

A four foot thick layer of foamed “concrete”, weighing 24 lbs per cubic foot, was placed beneath and around the new building. A normal weight reinforced concrete floor slab was placed over the lightweight fill for the vehicle showroom
and service bays.

Our geotechnical services included the
initial subsurface investigation, laboratory
testing, and extensive settlement analysis.
We evaluated the design alternatives to
reduce building settlement, developed
design criteria of the grading and
foundations. We then provided monitoring
and testing during construction.

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Gnoss Field Paving and Perimeter Levee
Novato, CA

Client: Marin County Public Works/Cortright & Seibold

Miller Pacific Engineering Group provided geotechnical design, consultation and construction observation  and testing services for a range of projects at Gnoss Airfield in Novato, California.  

The perimeter levee system was raised to improve flood protection and Miller Pacific Engineering provided construction
observation and testing services to verify contractor compliance with the plans and specifications, including minimum compaction levels and soil fill quality.

Distressed pavements in front of hangars and taxiways were also rehabilitated, and Miller Pacific Engineering Group was involved in design and construction observations.  Due to very soft soil subgrades, we recommended the use of geotextile fabrics to reduce the required pavement section, reduce the construction period and decrease project costs. 

The other “Gnoss Field” project was planning and feasibility reports for a major new hangar complex.  Fifty new hangars, taxiways, an office building and airplane “bridge” are proposed, pending environmental and economic hurdles. 

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