Design of cement stabilized soil retaining walls with concrete panel facing

In order to minimize the cost of earth retaining structures, particularly for the low to medium height retaining walls required by highway departments, a new design of retaining wall was investigated. This utilized facing panel units anchored into a cement stabilized compacted fill. Only short anchors are required to retain the facing panels, as mechanical stabilization of the cross-section is achieved by the addition of about 7% cement, rather than by reinforcing strips. The feasibility and applicability of this design has now been demonstrated, on the basis of this study which included laboratory testing, numerical and physical modeling, and full scale construction and instrumentation of two experimental retaining walls. Specifications have been prepared and these have been refined on the basis of full-scale experience. This design (which is non-proprietary) may be used in situations where proprietary designs are used nowadays, although there are significant differences in construction procedure from other mechanically stabilized earth designs. It is suitable for general non-specialized use, without requiring specialist subcontractors, and there should be some cost advantage, particularly for locations where cement is inexpensive. Unit cost was around $20 per square foot for the experimental wall, and would be reduced with wider acceptance. The main disadvantage appears to be that large differential settlements from compressible foundation soils cannot easily be accommodated.