Dynamic Replacement is an extension of the Dynamic Compaction process that is applicable for use on finer-grained, highly compressible and very weak soils. For this technique, the tamping energy drives imported, or site-sourced, granular material down into compressible soils to form large diameter soil reinforcement columns. Additional improvement can be obtained beneath the Dynamic Replacement columns in the underlying soil layers through the transmission of dynamic energy at depth. This method therefore combines the advantages of both Dynamic Compaction and Stone Columns by creating large-sized Dynamic Replacement inclusions with high internal shear resistance to promote compaction, consolidation and reinforcement of the foundation soils. The Dynamic Replacement technique is typically applied for heavily loaded and settlement sensitive structures whose stringent design requirements may not be achieved using traditional Dynamic Compaction methods.
Dynamic Replacement columns are formed by dropping a 10 to 20 tonne pounder from heights of 10 to 25 metres as determined by the initial soil properties and performance requirements. With this technique, granular inclusion to soil volume replacement ratios of 10 to 35 % can be achieved. For uniformly loaded structures or at sites where the location footing loads have yet to be determined, Dynamic Replacement can be applied over a regular grid pattern to create uniform soil improvement. Alternatively, Dynamic Replacement columns can be located beneath known footing locations for direct foundation support.
- Increases soil bearing capacity
- Reduces total and differential settlements
- Reduces the potential of soil liquefaction
- Well adapted to substantial loading conditions (up to 150 tons per column)
- Improves the factor of safety against slope failure under embankments
- Increases the time rate of consolidation due to enhanced draining characteristics
- Very high production rate can be achieved in comparison to other ground improvement techniques
Featured Dynamic Replacement Projects
Construction of a Grain SiloBécancour, QCThe Terminal Port of Quebec intended to build a 48m diameter, 35m high grain silo located within Bécancour harbour (Qc). Menard Canada was awarded the soil improvement works to be completed under the silo, truck shelter and conveyor bases. Treatment was performed with an offset in order to ensure proper confinement for the structures and achievement of both settlement and bearing... Read More