Cost Considerations
Cost is an important consideration when comparing microtunneling with other construction methods. Direct costs should not be the only consideration. Microtunneling has other benefits that...
Detailed Site Investigations
This section addresses site investigation issues that are important for detailed design and construction of microtunneling projects. These site investigations include the following: Geotechnical...
Pipe Characteristics
Microtunneling pipe should meet the following general requirements: Circular shape with a flush outside surface (including at the joints); Strength sufficient to withstand both the installation...
Pipe Design
The pipes and joints, once installed, must be capable of safely withstanding, for the project design life, all in-use service loads, including those associated with the following factors:...
Field Aspects
As soon as practical after their arrival at the project site, all pipes, fittings, and appurtenances should be thoroughly checked for compliance with the contract documents and accepted...
Microtunneling Operation
The shaft should provide safe working conditions and fully support the ground. Jacking and receiving shaft support system and sizes are typically determined by the contractor. See Chapter...
Machine Performance
Annular Thickness, Annulus, and Annular Space; Overcut; Slurry or Auger System; Cutter Wheel Design and Select; Slurry Separation Plant; Buried Objects and Obstruction; Steering....
Submittals
The contractor should submit the items listed in the specifications for review and acceptance by the engineer. The submittals are generally divided into preconstruction and postconstruction...
Shafts/Temporary Structures
Shafts should be of a size to accommodate the equipment and pipe selected and to allow for safe working practices. If the shaft must accommodate the permanent works, it is the contractor's...
Construction Support Services
A preconstruction survey of existing structures within the anticipated construction zone of influence should be conducted before any construction begins. A plan for structures that need...
Regulations
The contractor should meet federal, state, and local regulations. The contractor is responsible for jobsite safety....
Instrumentation and Monitoring
A detailed plan for monitoring possible ground surface movements caused by the microtunneling operations should be prepared. The plan is typically prepared by the engineer in consultation...
Restoration and Cleanup
The contractor should be responsible for site restoration and keeping the construction site clean, neat, and orderly at all times....
Measurement and Payment
The owner shall establish a bid schedule to obtain pricing for all work associated with the microtunneling installation. This bid schedule provides the bidders the opportunity to establish...
Filling The Bay: Deepening the Oakland Inner and Outer Harbors
The project to deepen the Oakland Inner and Outer Harbors from elevation -42 to -50 ft was federally authorized in 1999 to accommodate the next generation of post-Panamax container ships....
Innovative Use of a Groin Structure: Saving Cost, Shortening the Schedule, and Minimizing Impacts
Almost any type of construction activity can pose a shock to the surrounding environment and habitat. Obviously, the extent of the impact will depend on the location of the project and...
The New Bedford Marine Commerce Terminal
When construction of the first American offshore wind farm support terminal encountered greater challenges than expected, jet grouting enabled construction to continue....
Geo-Congress 2014
Technical Papers and Keynote Lectures
Proceedings of the 2014 Geo-Congress, held in Atlanta, Georgia, February 23-26, 2014. Sponsored by the Geo-Institute of ASCE. GSP 234, Geo-Congress...
Failure of a Large Circular Excavation
A circular excavation, 117 feet (36 m) in diameter by 90 feet (27 m) deep, was designed by an experienced engineering firm and construction was performed by an experienced contractor....
Failure of a Twenty-Foot High Retaining Wall
A cantilever retaining wall, designed in apparent accord with provisions in a civil engineering handbook, failed soon after construction. Analyses of the causes of the failure are presented....
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