چكيده به لاتين
Currently, conventional remediation of liquefaction triggering may have many environmental effects, and this important issue has led researchers to look for more sustainable methods. In this research, one of the new bio-improvement methods (biogas) has been used to generate gas-bubbles within a soil, susceptible to liquefaction. Using this method, two bio materials create ammonium ions and carbonate, in which ammonium ion is converted into nitrate and nitrite due to the presence of bacteria in water, and they are eventually converted to nitrogen gas in an anaerobic condition. The nitrogen bubbles created in water reduce the soil degree of saturation, which in effect increases the soil resistance to liquefaction occurance. In the present study, two sources of ureaze enzyme were used to reduce the soil degree of saturation. The effects of various parameters, including the optimum concentration of each substance for optimum time to generate gas bubbles, as well as the effect of the oxygen amount in water were investigated using monotonic triaxial tests. The results illustrate that the addition of refered two substances to the oxab or tap water decreased the pore water pressure due to desaturation. Finally, the substance containing the amount of oxab with the highest decrease in pore water generation, here called "optimum selection", was tested in the cyclic triaxial device, and the results were analyzed to evaluate liquefaction occurance using the energy approach. The outcome of these results revealed that compared with the strain energy of the non-treated sample, the treated sample had a much higher strain energy; in other words, the treated sample needed a larger amount of loading to trigger liquefaction.
