Abstract: The reinforcement of geotechnical materials plays an important role in the durability and safety of buildings. The construction waste is a huge, wasted resource and is currently largely produced in China. To improve the strength, the recycled powder construction waste is added to the soft soil. Based on the unconfined compressive strength test and the direct shear test of modified soil, re-developed constitutive model that combined with Drucker-Prager criterion is established by using platform ABAQUS platform. The geotechnical user material subroutine UMAT was used to predict the strength of the modified soil. The new constitutive model considers the influence of intermediate principal stress, the tensile stress and the hydrostatic pressure on the mechanical properties of the soil. The prediction results by the re-development platform are compared with the unconfined compression test results the soil specimens. Combined with the test and verification results, the appropriate amount of recycled powder was obtained to improve the soil strength. The results show that, it is beneficial to increase the strength of soil when the content of reclaimed fine powder is about 15 %. This subroutine command of ABAQUS can be used to describe and to predicte the mechanical properties of the modified soil well.

Key words: Modified Soil, Drucker-Prager Criterion, Unconfined Compressive Strength, Constitutive Model