Testing method for determining in-situ mechanical properties of rockfill material based on lateral pressure equivalent

The invention provides a testing method for determining in-situ mechanical properties of a rockfill material. The testing method comprises the following steps of: performing an in-situ lateral pressure test on a certain elevation part of a lateral pressure test hole to obtain a lateral pressure modulus value of the rockfill material; adopting a filling gradation at the elevation of the in-situ lateral pressure test as an original gradation to perform gradation scale reduction to obtain a simulated gradation, and preparing rockfill material lateral pressure physical models with different dry densities; carrying out a lateral pressure test in the rockfill material lateral pressure physical models, and determining a relation curve between the lateral pressure modulus of the simulated gradation of the rockfill material and the dry density of a prepared sample; finding the dry density of a material of the corresponding simulated gradation from the relation curve of the material of the simulated gradation and the d