Kleinfelder is providing geotechnical and materials testing services on Molycorp Project Phoenix, a $780 million expansion and modernization to Molycorp’s Mountain Pass Mine located in southeastern California.
This high-profile project required an aggressive schedule at a complex site that included relics of previous site activities. The coordinated design and construction of four major facilities needed to occur on sites of limited area and varied topography. The team constructed a rockfill test pad program to develop a performance specification for the more than three million cubic yards of rockfill placed for the project. The design team sought a Site Class C for economic considerations that Kleinfelder was able to provide early in the design, based on shear wave velocity testing and correlations of values obtained in existing fill at the site. The preliminary design values were validated with later testing of the completed rockfill test pad.
After identifying a “room problem” in the Mill area, additional building space would be required to accommodate the construction of a tank farm. To create the additional room, the client decided to extend the fill pad out onto a closed, 100-acre tailings impoundment and perform the site improvements needed to make this option viable, thereby tasking Kleinfelder with the evaluation.
The original alternative to address the need for additional building space was an expensive, time consuming site remediation program, including the possible implementation of specialized foundation design measures. Kleinfelder’s analyses showed an option that allowed immediate placement of fill without remediation—a solution that was successfully implemented, saving the client time and money.