The Scenic Drive reconstruction project consisted of the stabilization and reconstruction of a critical roadway (emergency response corridor) in La Honda, California. The roadway embankment failed during the wet winter season in late 2017 and dropped downslope up to 8 feet. In addition, three homes adjacent to Scenic Drive were damaged beyond repair due to the landslide movement, requiring complete demolition. The project presented multiple constraints throughout the planning, design, and construction phases. Balancing San Mateo County budgetary constraints, requirements of FEMA to satisfy funding eligibility, development of effective stabilization, and construction/staging footprint limitations led to a challenging project to execute within a short, accelerated project schedule. Innovative design solutions and consistent communication between the project owner, design team, and contractor provided for a successful project that was completed on time and below the allocated construction budget..
– APWA Silicon Valley California Chapter: 2022 Project of the Year – Disaster / Emergency Response
Kami Court Emergency Landslide Stabilization
The Kami Court emergency landslide stabilization project unloaded over 100,000 cy of material to arrest a large bedrock landslide moving at up to 92 feet deep, that was impacting private properties Investigation, monitoring, design, and construction of the stabilization measures were completed in three months. CE&G completed a preliminary evaluation of the landslide and recommended emergency stabilization measures to the Dougherty Valley Geotechnical Abatement District (DVGHAD).
– APWA Northern California Chapter: 2020 Project of the Year – Emergency Response
– CalGeo: 2020 Outstanding Project of the Year for Public – Medium Project Category
Penitencia Delivery Main and Penitencia Force Main Seismic Retrofit
The CE&G team, as a subconsultant to Carollo Engineers, and in collaboration with SCVWD, and California DWR, was retained to complete a landslide study and Landslide Displacement Hazard Analysis (LDHA) and provide geotechnical design and seismic retrofit recommendations to prevent catastrophic earthquake damage of three large pipelines that service the Penitenica Water Treatment Plant.
– CalGeo: 2019 Outstanding Project of the Year for Public – Medium Project Category
– Engineering News Record (ENR): 2018 California Best Projects Award – Water/Environment
Rifle Range Road Stabilization
The CE&G teamed with NCE and worked with the City of Richmond, to provide geotechnical engineering and structural design services for Rifle Range Road, which had been destabilized by a landslide and caused the loss of pavement on the downslope of the roadway. The emergency repair was conceived, designed, and constructed in less than nine months.
– APWA Northern California Chapter: 2019 Project of the Year – Emergency Response
Redwood Creek Improvements
The purpose of the 2017-2018 Redwood Creek Improvements Project (Jefferson Branch) was to improve the deficiencies of the concrete structures, while also ensuring the continued reliability of the stormwater collection system. CE&G provided geotechnical investigation and worked closely with prime consultant Wood Rodgers as consultants to the City. The project included replacement of a portion of the Jefferson Branch, which was the tributary of Redwood Creek with the most deflections. The length of the concrete rectangular channel portion was 236 linear feet.
– APWA North California Chapter: 2019 Project of the Year
Oro Loma Wet Weather Equalization & Ecotone Demonstration
CE&G worked with ESA and the Oro Loma Sanitation District to design an eco-friendly embankment that provides the following; equalization of high storm flows to the treatment plant, improved ecotone habitat for plants and animals along the bay margin, research site for biotechnical treatment to improve water quality, flood protection.
Geotechnical challenges included construction of embankments on soft bayfront sediments and expedited construction which required wick drains and instrumentation.
– CalGeo: 2018 Outstanding Project of the Year – Public – Medium Budget
– San Francisco Bay Institute: 2017 Bay Hero Award
– California Association of Sanitation Agencies (CASA): 2017 Outstanding Capital Project
– Friends of the San Francisco Estuary: 2017 Innovation award
Palomares Road Landslide Emergency Repair
On February 20, 2017, the uphill slope gave way, blocking both lanes of travel with debris. Associated rockfall boulders, one the size of a small car, also fell onto the road, along with mud, rocks, and saturated soil. CE&G was retained by the County to rapidly evaluate the conditions and provide design for emergency and permanent stabilization. CE&G determined thorough slope reconnaissance and rapidly deployed a UAS (drone) to identify that the primary debris flow source area was about 500 feet above the roadway. CE&G prepared emergency plans and specification’s to complete scaling (removing loose and unstable boulders, rocks, and soil from the landslide face) and construction of slope stabilization measures. 50,000 to 60,000 cubic yards of dirt and debris were removed. The permanent solution was an anchored wire mesh drapery system that terminated 8 feet above the roadway, preventing further damaging landslide activity.
– APWA Northern California Chapter: 2018 Project of the Year – Disaster or Emergency Construction/Repair, < $5M
Cull Creek Dam Spillway Modification & Creek Restoration
The CE&G team worked with the Alameda County Flood Control & Water Conservation District (ACFCWCD) to complete geotechnical engineering and provide resident engineering services during construction of the Cull Creek Dam Spillway Modification and Creek Restoration. The project restored Cull Creek to near natural conditions and mitigates seismic hazards associated with the original earth dam. The existing dam spillway was lowered by about ten feet, and sediment within the old reservoir was excavated to use on site as fill grading material for the restoration of downstream Cull Creek immediately upstream of the dam restoration.
– APWA Northern California Chapter: 2018 Project of the Year – Environmental, < $5M
San Francisco Bay Trail: George Miller Regional Trail
As a consultant to Contra Costa County in 2002, CE&G provided the geotechnical engineering and preliminary civil design and planning services for the conversion of the 1.7 mile-long abandoned section of Carquinez Scenic Drive into a segment of the S.F. Bay Trail. In 2011, CE&G was once again retained to provide geotechnical engineering and value engineering services on the project, this time as a subconsultant to the East Bay Regional Park District, who would develop the final design and construct the federally funded trail. The project included multiple retaining walls and a geofoam embankment.
– CalGeo: 2015 Outstanding Project of the Year for Public-Medium Project Category
Stanley Boulevard Streetscapes Improvements
This project entailed widening of a roadway to include a multi-use pathway. CE&G was initially retained by Alameda County to coordinate excavation and later, to review geotechnical design parameters for a retaining wall design. CE&G subsequently completed a geotechnical investigation and report for the project and designed and prepared PS&Es for a new design for a geogrid-reinforced segmental block retaining wall. CE&G provided construction engineering support and fast-tracked RFI responses and design alterations based on conditions encountered in the field.
– APWA Northern California Chapter: 2013 Sustainability Project of the Year
Alameda Creek Levees Upgrades and Accreditation
The CE&G team worked with the Alameda County Flood Control & Water Conservation District (ACFCWCD) to complete numerous geotechnical investigations and studies in support of FEMA levee certification studies. The work included investigation of over 18 miles of provisionally accredited levees that are under the jurisdiction of the ACFCWCD. The levees studied included two major levee systems (Zone 5 Line A – aka Alameda Creek – and Zone 2 Line B – aka San Lorenzo Creek) that were designed and constructed by the US Army Corps of Engineers in the 1960s. The geotechnical conditions of the riverine levees were investigated by drilling and sampling more than 100 borings and 200 cone penetration tests. In addition to the geotechnical investigations, CE&G also provided technical review of the project PS&E prepared for the deficient segment of the levees studies and field engineering services during construction of the needed improvements. The improvements have included construction channel stabilization measures, desilting, construciton of sheetpile and soil bentonite cutoff walls, levee raising, and construction of new inlet structures to improve hydraulic performance. CE&G personnel provided quality control materials testing and geotechnical engineering observation services during the construction of levee improvements required to obtain FEMA certification of the levee.
– APWA Northern California Chapter: 2013 Project of the Year – $5M >$25M
– ASCE San Francisco Section: 2013 Flood Management Project of the Year
Upper Sand Creek Dam and Flood Control Basin
CE&G worked as a geology and geotechnical subconsultant to investigate and design the flood control and recreational facility created by construction of an embankment dam across Sand Creek and excavation within the reservoir to create the necessary storage capacity. The basin is formed by a main dam and a saddle dike. The main dam consists of a zoned earth embankment with a crest length of 1,900 feet, a maximum height of 40 feet, and embankment volume of 300,000 cubic yards. The project was reviewed and approved by the California Division of Safety of Dams (DSOD).
– APWA Northern California Chapter: 2014 Overall Public Works Project of the Year and Project of the Year for Environmental Projects Between $5M and $25M
Vasco Road Safety Improvements Project
Vasco Road was formerly a rural road that now serves as a major commute route from east Contra Costa County and was in need of major safety improvements. CE&G provided geotechnical consultation, design services, and construction observations and testing in conformance with the Caltrans federal aid process for the realignment and safety improvements of approximately 1 mile of Vasco Road just north of Livermore and south of the County line. The geotechnical aspects of the project included excavations up to 100 feet high and construction of embankments up to 82 feet thick. At the request of Alameda County, CE&G prepared earthwork specifications and designed and prepared the plans and developed specifications for: the large cut slope with horizontal drains, a 45-foot tall segmental block retaining wall, and several other temporary retaining structures. CE&G also provided engineering and construction observations and testing throughout the construction of 1.75 miles of a required PG&E gas line relocation, and during the construction of the actual road project. Due to the relatively high anticipated construction cost estimate, the project underwent the Caltrans-mandated value engineering review process.
– APWA Northern California Chapter: 2010 Project of the Year
– Federal Highway Administration: National Roadway Safety Award
Peralta Creek Improvements
CE&G performed a geotechnical investigation and designed creek bank retaining systems to improve the hydraulic capacity and habitat of a man-made section of Peralta Creek. The site presented numerous challenges due to accessibility, space limitations, and unknowns regarding existing improvements. The project revitalized the socially disadvantaged urban neighborhood with park-like views and a restored creek.
– APWA Northern California Chapter: 2009 Project of the Year – Environmental <$5M
– ASCE San Francisco Section: 2009 Outstanding Civil Engineering Small Project of the Year
– ASCE: Outstanding Small Water Project in the State of California
– Association of Bay Area Governments: Growing Smarter – Preserving and Protecting the Environment Award
McKillop Road Stabilization
CE&G was retained by the City of Oakland to complete an emergency geologic and geotechnical study, prepare plans, specifications, and engineer’s estimate to quickly stabilize a roadway and secure several homes that were threatened by a landslide. A two-wall system was used in which the first wall with tieback anchors was constructed below the center of the roadway and a second wall connected with tie rods at the edge of the right of way. During construction of this FEMA-funded project, CE&G provided engineering observation, inspection, and testing services.
–APWA San Francisco Chapter: 2007 Emergency Project of the Year
Lakeshore Avenue Drainage Improvements
CE&G was retained by Alameda County to reduce flooding along Lakeshore Avenue between Lake Park Avenue and Mandana Boulevard. Because Lakeshore Ave is a heavily travelled area with average daily traffic of over 48,000 vehicles, construction faced many difficult challenges such as traffic control, working hours, public safety, as well as preservation to Oakland’s historical structures. CE&G provided geotechnical engineering consulting services for construction of a 3000-foot long 6×8 foot pre-cast concrete box culvert adjacent to an existing cast-in-place box constructed in the early 1960s. The outfall of the line discharges into Lake Merritt. The variable soil conditions along the alignment required that the downstream 1200 feet of the line be supported on driven piles while the remainder of the project could be constructed as a conventional cut and cover box culvert. The project was completed in 2005 with virtually no claims from the contractor.
– APWA Northern California Chapter: 2006 Distinguished Project of the Year – Storm, Sewer or Water Facilities