FS-Soil cement column
Foundation Specialists, Inc. has developed and perfected over the last twenty years a soil-cement consolidation system initially called and patented with the name “CSS” (or “Chemically Soil Strengthening” system) and lately improved and likewise patented with the name “FS Soil-cement Column”. The “FS Soil-cement Column” system is particularly suited for the very poor and water saturated soil formations found in the coastal areas of the Philippines, where the soil in general is characterized by very low bearing capacity and low shear values. The overlaying soil strata of this formation have an extremely high liquefaction potential in earthquake condition.
FS has developed the technology, the tools, and the in-situ mixing procedures, which have permitted to establish the method’s complete reliability.
The “FS Soil-Cement Column” method produces high mechanical characteristics shear and compressive strength for the soil treated, maintaining the costs affordable and competitive. FS uses different tools and procedures for different soil types to achieve maximum soil strength.
The method applies well for clay, silt, sand, peat, gravel, organic material and all combination of the above.
Unlike other soil improvement systems, “FS Soil-cement Column” system works equally well with high or low water table, various granulometry of the soil to be treated, in presence of organic material, and with soil having high liquefaction potential.
One more application of "FS Soil Cement Column" is to form retaining walls to protect excavation in areas where the high water table and the unstable soils do not permit unprotected excavation.
The relatively low cost and the versatility of this technology as compared to steel or concrete sheet piling walls or diaphragm walls are very strong reasons for this method's increasing favor amongst structural engineers.
The photo above shows the 550mm. diameter FS Soil-Cement Column with embedded H-beams as reinforcement executed by FS as foundations sub-contractor of TAISEI for the new Bulletin Building in Intramuros, Manila. The size of the column (550 mm) is smaller than the standard one of 800 mm because space between the old building’s footings and the new building’s foundations to be excavated and installed could only accommodate 550 mm diameter columns. Purpose of the reinforced FS Soil-Cement Column as in the figure, was to form a secant-column retaining wall to protect the very old adjacent building from the effects of the pit excavation for the new building’s foundation.
In the National Museum (formerly Finance Building in Rizal Park, Manila), retaining wall for 4m. and 5m. deep excavation in very soft soil (SPT count = 2) was executed by use of “FS Soil Cement Column” 800 mm diameter on two parallel lines.