The invention discloses a macroscopic method capable of distinguishing expansibility grade of
soil mass during construction. The method is characterized in that before
project implementation, a representative sample in a work area is selected and is subjected to an indoor test of a free
swelling ratio, the relation among the expansibility, the lithological character, the
soil mass structure, colors, crack development characteristics and the like is established, and the accuracy and the scientificity of on-site rapid distinguishing are realized; a macrocontrol index for rapid distinguishing of the expansibility grade of the
soil mass is selected, and classified description and research of a control index are carried out; a soil
mass expansibility distinguishing model is established, the weight of each
influence factor is determined, besides, an indoor
verification test is carried out, and the reliability of the model and the accuracy of the test are improved; rapid distinguishing work of the expansibility grade of the soil
mass in the work area is performed on site according to the soil
mass expansibility distinguishing model. The defects that a treatment scheme and treatment strength cannot be adjusted timely in the implementation process of a project according to the expansibility grade in the prior art are overcome, and the method has the advantages of capability of rapidly distinguishing
expansive soil in the on-site construction process.