Study on in-situ test on mechanical properties of the particle improved roadbed in permafrost

The adoption of particle improved roadbed (PIR) is one of the proactive measures to protect permafrost from warming and thawing in cold regions. The field plate loading test was performed to study the mechanical parameters of fillings after a freeze–thaw cycle, including bearing capacity, modulus of deformation, etc. In addition, the deformation features of the roadbed fillings were analyzed and discussed. The results indicated that the allowable bearing capacity of the roadbed fillings was 418.78 kPa, and the deformation modulus and shear modulus decreased with the increase of the loads. It is reasonable to consider the roadbed fillings as a three-dimensional elastic continuous medium to establish a model to study deformation of permafrost. The calculated deformation agreed well with the measured. Therefore, the model can provide reference for the deformation predication of other roadbed fillings in permafrost.