Abstract: Dolomite sandification is a typical geological problem in Yuxi segment of Central Yunnan Water Diversion Project. Accurate physical and mechanical parameters of sandy dolomite could offer basis for construction and design, and ensure the safety of life and property of construction personnel. Due to broken structure, intensively sandy dolomite is difficult to be made into standard specimens for laboratory test to obtain its mechanical parameters. In view of this, the mechanical parameters of intensively sandy dolomite is estimated by using Hoek-Brown strength criterion based on field investigation and needle penetration test. The estimation results are compared with those of field adit test. Results manifest that Hoek-Brown strength criterion has good application effect in estimating the mechanical parameters of intensively sandy dolomite rock mass because most of the estimated values are within the range of test results. In addition, the recommended values of mechanical parameters of intensively sandy dolomite in the study area are given to support engineering construction.

Key words: sandy dolomite, intense sandification, Hoek-Brown strength criterion, needle penetration test, estimation of rock mass mechanical parameters