Controlled Modulus Columns ( CMC ) : Application to the support of Mechanically Stabilized Earth Walls ( MSE Walls )

摘要

The patented CMC system fits in the generic category of inclusions. The design technology behind the development and experience with CMC makes them uniquely efficient for the immediate support of MSE walls and embankments for public transportation, other infrastructure facilities, large storage tanks, and building facilities. Traditional embankment and fill wall construction for road and rail corridors had placed little value on time in developing the engineering schemes for settlement control prior to placing pavement. As an improvement to the least first cost alternative - waiting for primary consolidation to occur - when working above fine-grained soils prone to long term consolidation, wick drains with surcharge have been commonly applied to speed up the settlement process. This approach can still take up to 1 year depending on site conditions, wick drain spacing, thickness of the slow-draining layer, and the degree of consolidation desired prior to paving. Accelerated construction of embankments, with immediate placement of roadway pavements over compacted embankment fills offers a very desirable solution. CMCs, as well as other types of rigid and semi-rigid inclusions systems, are an ideal solution for the immediate support of embankments. CMCs are designed using special proprietary finite element techniques that include the effects of load sharing between the distribution platform, the columns, and the surrounding improved ground. The paper summarizes the design approach, and presents case histories of completed public facilities supported on CMC foundations. The case of an MSE bridge approach in Southern New Jersey will be discussed in details and the support of another MSE Wall in Northern New Jersey will be briefly presented.