预制节理岩体试件强度及破坏模式的试验研究

采用相似材料模型试验对不同节理倾角、节理贯通度、节理组数、载荷应变率、试件长径比、节理充填物厚度及类型等7种工况下的预制节理岩体在单轴压缩下的峰值强度及破坏模式进行了研究。结果表明：节理岩体的破坏模式及峰值强度与节理构造形态密切相关。贯通节理岩体将产生沿节理面的剪切破坏或穿切节理面破坏，且与第1种破坏模式对应的岩体峰值强度更低。非贯通节理岩体的强度介于完整岩体和贯通节理岩体之间。随着平行节理组数的增加，岩体峰值强度逐渐下降。随着载荷应变率的增加，岩体峰值强度逐渐增大，相应地试件的破坏模式也变得更加复杂。试件长径比基本没有改变其破坏模式，完整试件仍主要是以张拉破坏为主，而节理试件仍以剪切破坏为主。随着长径比增加，试件峰值强度逐渐增大。随着节理充填物厚度增加，试件峰值强度降低。不同节理填充物对试件峰值强度也有一定影响。

Test study of strength and failure mode of pre-existing jointed rock mass

Strength and failure modes of pre-existing jointed rock mass with different joint dip angles, joint discontinuity degrees, joint sets, load strain ratios, slenderness ratios, joint filling’s depths and its sort under uniaxial compression are studied by means of similar material model tests. The results show that failure modes and peak strength of jointed rock mass are much related to joint configuration. Shear failure along or tensile failure across the joint face will occur in the continuous jointed rock mass, in which the peak strength is less corresponding to the first failure mode. To discontinuous jointed rock mass, its peak strength lies between that of intact rock and continuous jointed rock mass. With increase of parallel joint sets’ number, strength of rock mass gradually decreases. With increase of loading strain ratio, peak strength of rock mass gradually increases; and its failure mode becomes complicated. The slenderness ratio does not change the failure mode of the rock mass; and the intact specimens mainly show tensile failure; while the jointed ones mainly show shear failure. With increase of the slenderness ratio, the peak strength gradually increases; while to joint filling’s depth, it is reverse. The effect of different joint’s fillings on the specimen’s strength exists.