U.S. Army Corps of Engineers’ Pittsburgh District seeks expert advice from specialty geotechnical construction firms experienced with the performance of jet grouting to determine ways to improve and reuse existing on-site soils present at the site of the new Montgomery Locks and Dam river chamber near Monaca, Beaver County, Pa. Experience in constructing micropiles would be beneficial because there are secondary issues related to deep seated sliding of the cofferdam structures on a surficial weak rock.
This is a request for advice from the Corps; it is not a contract solicitation.
This project will install 2000 LF of cofferdam to allow for portions of the new lock structure to be constructed in the dry. The length of the structure is split approximately in equal lengths with about 1,000 LF of damming surface located both downstream and upstream of the existing structure.
Once the cofferdam damming surface has been constructed (installed) there will be some amount of existing alluvium present within each cell, presenting a significant impact on the overall cost of construction and project schedule since removal and subsequent disposal of the material then must be considered. ACE is “soliciting industry advice about cost-effective alternatives to managing the existing alluvium in-situ rather than resorting to total removal and replacement.” ACE asks whether soil mixing is possible to create a cementitious-type material to allow for the existing soils to remain in place. And, can a portion of these soils create a tremie seal securing the project’s foundation.
This Notice states that “USACE intends to award a large construction contract for completion of the new chamber which will include cofferdam construction as an early phase activity.” And an industry day is planned for this upcoming project. Contact Matt Desjardins - matthew.c.desjardins@usace.army.mil.