By analyzed the uniaxial compressive strength test results, no. 8 specimen under normal maintenance conditions, No. 2 specimen soaked at PH=4 for 60d, No. 1 and No. 8 specimens soaked at PH=4 for 90d, No. 6 and No. 10 specimens soaked at PH=2 for 60d and No. 4 specimen soaked at PH=4 for 90d had significantly greater differences in compressive strength values than the other values. This is due to errors in the preparation of the rock-like material configuration and errors caused by the uniaxial compression test procedure.

To ensure the reliability of the data, the larger deviations were excluded. The average of the peak stresses of the other specimens was taken as the measured value of the specimens under natural and acidic conditions, and the specimen closest to the average was selected as the representative specimen. The mean values of the peak stresses of the specimens under different conditions and the peak stresses of the representative specimens are shown in Table 2.

Table2 Average and representative peak stress under different immersion conditions (MPa)