Tag Archives: tunnel

Lavergne Avenue Sewer Project , Tunnel and Reservoir Plan

Chicago, Illinois

Chicago Department of Water Management constructed a relief sewer, including a series of drop shafts, drain connections, catch basins and inlets along North Lavergne Avenue. This $20 million project replaced a 100-year-old sewer, preventing flooding in neighborhood homes. Jay Dee Contractors performed this work, which included installation of over 2,600 feet of reinforced concrete pipe sewer in a shallow tunnel (about 60 feet below the ground), five drop shafts connecting to the shallow sewer tunnel or to the existing deep tunnel (over 200 feet below grade), and connection structures to join the two tunnels. G2 Consulting Group assisted Jay Dee by evaluating subsurface conditions to guide construction techniques.

Fast Facts

Project Owner

Chicago Department of Water Management

Scope

G2 identified dewatering requirements for construction of the drop shafts, providing shaft designs through both soft ground and underlying rock leading to the deep tunnel, and evaluating design alternatives to meet requirements for constructing the shallow tunnel under an existing railroad line. In addition, G2 assisted Jay Dee Contractors during tunnel construction when the tunnel boring machine unexpectedly encountered saturated soils.

G2 Services Provided

Geotechnical Investigation and Design

Challenges/Solutions
    • Tunnel shafts were drilled through soft soils which overlay a deeper rock layer. Limited data was available to define the interface of these two layers. G2 conducted a geotechnical investigation to characterize existing conditions and evaluate dewatering techniques for construction of the shafts.
    • One of the shafts extends over 230 feet, connecting the new shallow collector tunnel to the existing deep tunnel. G2 developed shaft construction designs to provide stability in the soft soil conditions and in the rock.
    • As the tunnel was being constructed, saturated soils halted work.  G2 assisted Jay Dee by designing an approach using grouting and dewatering techniques to enable work to continue.
    • An existing railroad line crosses over the alignment of the new tunnel.  G2 assisted Jay Dee Contractors as they analyzed design alternatives to meet the railroad’s requirements.

Smart. Results. Fast. G2’s geotechnical solutions facilitated an expedited construction schedule for this highly visible project by simplifying excavation of the tunnel drop shafts and addressing construction challenges during tunnel boring.

Dugway Tunnel Project

Cleveland, Ohio


Part of Cleveland’s long term plan to control sewage discharges into Lake Erie, the $179 million Dugway Storage Tunnel intercepts high water flow and directs it to proper treatment before discharge to Lake Erie. This project included the installation of a 24-foot diameter, 15,000-foot long storage tunnel at depths approaching 200 feet below ground level. Several consolidation sewers, diversion structures, and drop shafts were constructed to capture and store combined sewer overflow from the service area.

Fast Facts

Project Owner

Northeast Ohio Regional Sewer District

Scope

G2 Consulting Group designed shafts ranging in configuration from circular with concrete ring beams to trapezoidal with steel bracing to facilitate construction of both tunnels and junction chambers.

G2 Services Provided

Geotechnical engineering
Geotechnical instrumentation monitoring

Challenges/Solutions

      • Work was performed in populated areas, and the construction approach minimized impact on this population. G2 designed remote geotechnical instrumentation to monitor construction activities, including vibration, providing the team access to this important data on a real time basis.
      • This project was on a fast-paced schedule. In cooperation with Walsh, G2 submitted plans and specifications for all 6 Phase I shafts within 30 days of Notice to Proceed.

Smart. Results. Fast. G2 completed design of 6 shafts within 30 days to meet critical project milestones.

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Dugway Tunnel Project Underway in Cleveland

G2-49

Mark Stapleton, P.E.
Project Manager

The Northeast Ohio Regional Sewer District is completing a massive stormwater control project in the Cleveland area to protect Lake Erie, while meeting the needs of their growing community. G2 Consulting Group worked closely with Walsh Construction to submit plans and specifications for several shafts within 30 days of notice to proceed. Check out the video below for more project details.

(Double click on image below to see on full screen)

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