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.