A rapid consolidation and compaction method for densifying various layers of soils and intermediate geomaterials in a soil deposit, the rapid consolidation and compaction method comprising:
- (i) installing porous displacement piles comprising a pipe section with a removable end plate and filled with compacted sandy soils, in at least one layer of very soft, soft, medium stiff, stiff, very stiff clayey and silty soil for the rapid consolidation and densification of the clayey and silty soil and/or of very loose, loose, medium dense, dense sandy soil for instantaneous densification of the sandy soil;
- (ii) first driving a non-displacement pile comprising of a pipe section into ground;
- (iii) filling and compacting each and every layer of the sandy soil to a specified relative density in the pipe section attached with the removable end plate when the said pipe section is held laterally in vertical position above a ground surface, either at the same location where the said pipe section filled with compacted sandy soil and with the removable end plate to be driven into the ground or at a distant location other than where the said pipe section filled with the compacted sandy soil and with the removable end plate to be driven into the ground;
- (iv) the compacted sandy soil to be in compliance of a filter design criterion, gradation, that is particle size distribution of the compacted sandy material shall be designed to allow free flow of the excess water for dissipating the excess pore-water pressures or the excess pore-air pressures and also to prevent migration of fine particles of in-situ soil;
- (v) driving the displacement pile comprising the said pipe section filled with compacted soil and with the removable end plate into the ground through inside the non-displacement pile;
- (vi) after driving the displacement pile, placing a weight or a hammer on top of the compacted sandy soil in the pipe section before pulling the pipe section out of the ground;
- (vii) during pulling the pipe section of the displacement pile out of the ground, the removable end plate opens 100 percent of inside area of the pipe section;
- (viii) during pulling the pipe section of the displacement pile, placing the weight or the hammer on top of the compacted sandy soil in the pipe section in order to continue to push the compacted sandy soil vertically downwards to fill the compacted sandy soil in the space previously occupied by the pipe section to form a column of compacted sandy soil;
- (ix) leaving the column of the compacted sandy soil in the ground, after pulling out of the pipe section of the displacement pile out of the ground;
- (x) therefore, an area of cross-section of the column of the compacted soil is at least equal or more than the inside area of the pipe section;
- (xi) the column of the compacted sandy soil left in the ground after pulling out of the pipe section, behaves as a porous displacement pile up to a depth up to which the pipe section of the displacement pile was driven;
- (xii) the porous displacement pile occupies space previously occupied by the clayey and silty soil and develops excess pore-water pressures in saturated clayey and silty soil and the excess pore-water pressures and the excess pore-water pressures in partially saturated clayey and silty soil, by pressurizing the pore-water and pore-air present in the pores of the saturated clayey and silty soil;
- (xiii) the excess pore-water pressures and pore-air pressures developed in the clayey and silty soil are rapidly dissipated by flow of the pressurized pore-water and pore-air through the porous displacement pile to the ground surface or to the sandy layer located within the ground, thereby densifying the clayey and silty soils;
- (xiv) the displacement pile displaces the at least one layer of sandy soil below the non-displacement pile;
- (xv) the porous displacement pile occupies the space previously occupied by the sandy soil reducing volume of voids of the soil matrix and densifying the sandy soil instantaneously;
- (xvi) in the sandy soil, the excess pore-water pressures do not develop and if develop, dissipate immediately;
- (xvii) installing a plurality of the porous displacement piles spaced apart in a grid pattern in the entire area requiring densification;
- (xviii) installing the porous displacement piles either vertically or at a batter;
- (xix) wherein using one of following three methods for compacting sandy soil in the pipe section above the ground;
- (xx) in first method, filling the sandy soil in the layers in the pipe section and compacting and densifying each layer by drops of the hammer or the weight;
- the sandy soil is filled in the layers in the pipe section and each layer compacted and densified by drops of the hammer or the weight;
- (xxi) wherein a connecting rod connects the weight or the hammer to a boom of crane or to a pile driving hammer;
- (xxii) in second method, filling each layer of the sandy soil in the pipe section and placing hammer or weight on the top of the sandy soil in the pipe section;
- (xxiii) wherein then a surface vibrator is attached on side of the pipe section and the pipe section is vibrated to compact and densify each layer of the sandy soil inside the pipe section;
- (xxiv) in third method, filling each layer of the sandy soil in the pipe section and placing the hammer or the weight on the top of the sandy soil in the pipe section and vibrating the hammer or the weight for densifying the sandy soil inside the pipe section;
- (xxv) the pipe section during compaction of the sandy soil is laterally supported to maintain the pipe section in vertical position;
- (xxvi) wherein depending on subsurface soil conditions at a site, and specifications up to which subsurface soil layers to be densified at that site (a) compacting the sandy soil in the pipe section to a particular relative density to either medium dense or dense or very dense sand condition and (b) using appropriate spacing and diameter of the porous displacement piles in the grid pattern.