| Compaction combined preloading of dynamic drainage consolidation method for reinforcingsoft soil have been extensively applications in practical engineering, but the study ofreinforcement mechanism is still not perfect. Based on the site geological data andreinforcement method of Shantou municipal infrastructure construction of soft soil foundationtreatment project, the indoor experiment of compaction combined preloading reinforcementsoft soil is designed. Through the indoor experiment of preloading and compaction dynamictest, the consolidation law of soft soil is analyzed and compared with the existing calculatedmethod of soft soil final settlement includes standard method and curve fitting method. Thepropagation of compaction energy and dynamic characteristics and response are studied.There are some conclusions:(1) During the process of consolidation settlement, theoretical calculation of the degree ofconsolidation result is larger than the measured result, and the difference increases first andthen decreases. The difference is lager in the early settlement. When the measuredconsolidation degree is greater than90%, the difference with theoretical calculation result isless than8%. It is verified that the reliability of the consolidation degree theoreticalcalculation results.(2) The final settlement calculated by standardized method is16.3%larger than themeasured result. With the measured observation data of68h, the final settlement is calculatedthrough the curve fitting method. The results calculated by Hyperbolic method are17.8%larger than measured results, the results calculated by Logarithmic curve method are10.7%smaller than measured results.(3) The acceleration and speed caused by compaction vibration are decreases with thedistance and depth increased, and the acceleration increases with the number of tamping.Compaction energy is decayed by the form of negative exponential function. Theinfluence range of dynamic compaction in the vertical direction is greater than the horizontaldirection, and the decay of speed is faster than acceleration. At the3times hammer diameterin the horizontal direction and the vertical direction, the attenuatio n of compaction energy are all more than90%.(4) The excess pore water pressure caused by compaction dissipates with time. The excesspore water pressure dissipates completely, the soil consolidation degree is91%. The processof soil compressed consolidation is as the process of excess pore water pressure dissipated.Excess pore water pressure dissipates completely, soil consolidation degree is over90%.(5) According to the void ratio changes before and after dynamic consolidation, can bededuced22.5N m of compaction energy is equivalent to13.5kPa average load or1m thickfill preloading apply on soft soil and the consolidate86h. The settlement is quite with theconsolidation settlement caused by dynamic compaction. The effect of dynamic consolidationon soft is obvious... |
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