Four polyacrylate materials with different mass ratios of soft and rigid segment were made by semi-continuous pre-emulsified seed emulsion polymerization. Methyl methacrylate (MMA) and butyl acrylate (BA) were used as soft and rigid segments, and acrylic acid (AA) was used as the functional segment. The composite emulsifiers were composed of sodium dodecyl sulfate (SDS) and alkylphenol polyoxyethylene ether (OP-10). In this study, we successfully fabricated polyacrylate (PA). The morphology of the latex particles was spherical, with a diameter of similar to 200 nm. With the increase of BA content, the glass transition temperature (T g ) of PA decreased. The PA curing agent could significantly improve the soil's mechanical property and water resistance. The compressive strength of PA-1 solidified soil increased to 2.67 MPa, which 187 % higher than the pure soil sample (PA-0). Meanwhile, PA-1 solidified soil would not break down after being immersed in water for 30 days. This indicated that PA emulsion had an efficient solidification ability and a good water resistance, which was beneficial to sand fixation and slope protection.

With the advancement of ecological and environmental protection construction, the research on the modification of expansive soil using environmentally friendly polymers can make up for the harm to the ecological environment caused by traditional modification. Mechanical and microscopic properties of modified expansive soils were analyzed through indoor tests. The results showed that the liquid limit and plasticity index decreased by 52.14% and 77.36%, respectively, and the plastic limit increased by 20.83%. Maximum dry density decreased by 5.11% and optimum moisture content increased by 28.47%. The compressive and shear strength increases and then decreases with the increase of dosage, and the strength reaches the maximum when the dosage is 4%, and the vertical and lateral deformation of the specimen is the smallest. Modified soil swelling was reduced by 54.57% and swelling forces were reduced by 15-57%. The modified soil cracks developed slowly and the width of the cracks was reduced by 61.68% after the modification. Microscopy showed that no new minerals were generated after doping modifier, while hydrophilic minerals were reduced by 43.14%, and the gel film formed by hydration made the pores smaller and the structure tighter by filling and wrapping on the surface of the particles.