The uniaxial compressive strength (UCS) is one of the most basic parameters in geotechnical investigation; it is widely used in the rock foundation design

surrounding rock classification

rock mass classification

rock excavation grading

and rock foundation check and its acceptance. Proximately

70% of Chongqing urban area is located in the middle Jurassic Shaximiao Formation; so that the UCS has great significance in Shaximiao formation research. From the exploration project practices

this article seeks to establish the relation between the UCS and the softening coefficient of Shaximiao formation rock. An empirical formula has been established between the saturation and natural compressive strength by comparing the calculated values and the large number of experimental values. The results show a high reliability of the calculated values which can replace the experimental values to get a broad application prospects.