土石混合体变形破坏的基覆面效应研究

为了研究含石量的变化对土石混合体变形破坏演化规律的影响，考虑了基覆面效应的含石量因素，对土石混合体的变形破坏问题进行了分析.采用自主设计的大型推剪仪对剪切面与基覆面的夹角进行了研究，得到了不同含石量情况下最大剪应力的变化规律，借助渗压计与土压力计研究了孔隙水压力与土压力的变化规律.研究结果表明:当含石量从10%增加至50%时，相同剪切位移情况下土石混合体的抗剪强度会增加，剪切面与基覆面的夹角增加80%；在基覆面底部，剪切面与基覆面的距离增加63.6%；土石混合体变形破坏的最大剪应力即峰值强度增加32.5%；孔隙水压力变化值达到最大值所需的时间增加78.9%；土压力变化值达到最大值所需的时间增加80%；在试验过程中石块会发生翻滚旋转，不会发生被剪断，石块最终会指向土石混合体剪切破坏的方向. 

Study of Bedrock Surface Effect under Different Percentages of Rock

The laws of deformation and failure of soil and rock mixtures under different percentages of rock were analyzed in this study, while considering the percentage of rock of the bedrock surface effect. Firstly, the intersection angle of bedrock surface and shearing surface was studied using an in-house developed large shear test. The maximum shearing stress change law was studied under different percentages of rock. The change laws of the pore water pressure and earth pressure were studied using the pore water pressure gauges and earth pressure gauges. The results showed that the shearing strength of the soil and rock mixtures increased under the same shearing displacement as the percentage of rock increased from 10% to 50%, the intersection angle of bedrock surface and shearing surface increased by 80%; the distance of the bedrock surface and shearing surface increased by 63.6% at the bottom of the bedrock surface as the percentage of rock increased; the maximum shearing stress increased by 32.5% as the percentage of rock increased; the time increased by 78.9% when the pore water pressure change value reached the corresponding maximum value as the percentage of rock increased. The time increased by 80% when earth pressure change value reached the corresponding maximum value as the percentage of rock Increased. The rock rotated, but the remained undamaged. The rock pointed to the shearing failure direction of soil and rock mixtures.