The Foundation Specialists, inc. has developed and perfectioned over the last 20 years a soil-cement consolidation system called initially "CSS" or "Chemical Soil Strengthening" and eventually soil-cement column treatment or "FS-Soilcement Column" system. The "FS-Soilcement Column" system is particularly suited for the very poor and water saturated soil formations found in the coastal areas of the Philippines, where the very low bearing capacity and low shear values of the soil in general is coupled with extremely high liquefaction potential (in earthquake condition), of the overlaying strata.
Foundation Specialists, inc. has developed the technology, the tools, the in-situ mixing procedures which have permitted to establish the method's complete reliability.
The FS method produces high mechanical characteristics shear and compressive strength for the soil treated, maintaining the costs affordable and competitive. Different tools and procedures are used by FS for different soil types, in order to achieve maximum soil strength, but the general procedures are the same: the "FS-Soilcement Column" system process is carried-out by employing high torque capacity rotary equipment with continuous kelly bars, and continuous injection of cement which is then mechanically mixed to the soil particles by special tools attached to the kelly bar. Each soil type requires a specially designed tool in order to optimize the mixing of the original soil with the cement introduced in it.
The cement is hydrated and reacts with the soil particles forming eventually a solid rocky conglomerate with good mechanical characteristics.
Unlike the other soil improvement systems, the "FS-Soilcement Column" execution is not negatively influenced by high or low water table, by granulometry of the soil to be improved, by the presence of organic material, or by the quality of the water in the water table.
The method applies well for clay, silt, sand, peat, gravel, organic material and all combination of the above.
The resulting structures, as the name implies, have the shape of cylindrical columns with the diameter given to them by the diameter of the tool used: the diameter most used by FS is 800 mm which has been proven to be the most cost effective.
Unlike the products of other soil densification technologies, the "FS-Soilcement Columns" are not negatively affected by the soil liquefaction of the surrounding soil happening during earthquake. In fact, the soil improvement is produced by the cementation of soil particles into a rock-like structure. FS-Soilcement Column" treatment can be designed also to form cells and barriers to effectively prevent liquefaction to happen within the area of the "FS-Soilcement Column".