According to the viewpoint that the kind of brittle spalling of wall rock is the embodiment of in-situ rock stress

a new evaluation method of general geostress is put forward based on spalling features of wall rock. Firstly

the spatial relationship of three principal stresses is gained through the analysis of spalling features of wall rock from the aspect of spatial distribution and intensity relation. Then

the direction of maximum principal stress is counted according to the trend of spalling’s split veins. The values of three principal stresses are calculated also based on the stress threshold values of spalling and threshold values of crack initiation. The in-situ stress evaluation of right powerhouse region in Baihetan hydropower station is validated by the local measured in-situ rock stress results and contrastively numerical analysis of different directions of maximum principal stress

which prove that the method is reasonable and useful for understanding the break of wall rock and checking the measured in-situ rock stress results.