Acid-modified method for loess aseismic subsidence and its microstructure analysis

The loess with low viscosity and large number of powder particles, has weak-cemented and more frame-holes microstructure, which could lower its dynamic strength and induce large seismic subsidence deformation under dynamic loading. It brings some challenges technology problems for foundation treatment in engineering construction. The acidified modification method is through by changing the loess microstructure from base to reduce its dynamic deformation and collapsibility. The modification method is by adding below, the boron chemical compound, the main materials can produce strong dispersed and cemented effect, light calcium carbonate, to adjust the original loess particles size gradation, and the diluted phosphoric acid, to adjust the original loess pH value. Moreover, through contrasting the seismic subsidence test and others by different ingredients, then analyzing its microstructure and energy spectrum before and after modification, the best proportion of ingredient is determined. The study results show that the acid-modified method can change the loess microstructure and reduce the seismic subsidence conefficients effectively. In addition, the all modified adding materials have non-toxic, and have no pollution to the soil.