Method of compaction of foundations laid with soft mineral soils

摘要

FIELD OF THE INVENTION The invention relates to the construction industry, and in particular to the field of soil compaction of foundations and foundations of buildings (including power industry buildings). The technical solution of the present invention is to realize the compaction of the foundation constructed through the soft mineral soil by setting the best technical design parameters of the compaction pile for the total area of the foundation. The essence of the invention is as follows. Pre-engineering and geological surveys in the area of foundations in the method of compaction of foundations made of soft mineral soils, including borehole formation, supply of sealant to each borehole, and impact of hollow tubular working tools on the sealant to form compaction piles; Determine the deformation coefficient, Poisson's ratio, internal friction angle, non-adhesion, specific gravity, and initial porosity ratio of soft mineral soil. Thereafter, the ε i value of the expansion strain of each borehole is set equal to 0.1, and the void ratio of the soft mineral soil after compaction around the compaction pile is calculated. For each step, the predicted value of the soft mineral soil liquidity index is calculated according to the formula below. The nearest tentative value of the deformation coefficient of the mineral soil surrounding the compaction pile as the standard value now exists after the above is calculated according to the void ratio of the soft mineral soil after compaction around the compaction pile and the value of the soft mineral soil liquefaction index after compaction. The placement stride of the compaction pile represents the three diameters of the hollow tubing tool and the actual average effective strain coefficient is calculated. Compare this to the design strain coefficient of the mineral soil. If the actual mean effective strain coefficient of the underlying soil is smaller than the design factor, the εi value of the borehole expansion strain is iteratively used with a magnitude of 0.1. The calculation of the actual mean effective strain coefficient of the foundation is repeated until the design value also achieves a compaction pile placement step equivalent to 1.5 times the diameter of the hollow tubular working tool. The expansion of the borehole diameter equivalent to the expansion strain caused by the press-fitting process is calculated according to the formula below. and the length of the compaction pile is equal to the distance from the roof to the floor of at least one layer that requires compaction. A hollow tubular working tool is press-fitted to create a borehole corresponding to the length of the compaction pile. The feeding of the sealant into the borehole is effected through the bore of the hollow tubular working tool and the compressive effect to form the compaction pile is effected through the hollow tubular working tool which is press-fitted into the sealant. Subsequent engineering and geological investigations in the footing area determine the coefficient of deformation of compacted mineral soils between compacted piles. Calculate the actual mean effective strain coefficient of the compacted foundation and compare it with the design value. And if the value of the actual mean effective deformation coefficient does not match the design value, an additional compaction pile is constructed between the previously constructed compaction piles.