Abstract: The collapsibility characteristics of wind-blown sand in Thar Desert of Pakistan are investigated based on preliminary survey findings and collapsibility test results. The correlation between basic physical indexes of wind-blown sand and collapsibility are also examined. Results demonstrate that the collapsibility of wind-blown sand is mainly distributed in layer ① and layer ②, and the average collapsibility coefficient is 0.039, indicating slightly to moderately collapsible. The grain composition and soluble salt characteristics of wind-blown sand are the main internal basis of collapsible deformation. In addition, strong dispersion is found between collapsibility coefficient and water content of the wind-blown sand. Collapsibility coefficient is also positively correlated with porosity and linearly negatively with dry density. When porosity is smaller than 0.65 or dry density exceeds 1.60 g/cm³, wind-blown sand is not collapsible.

Key words: Thar desert, wind-blown sand, collapsibility, physical indexes, correlation