Abstract Due to the ice-water transition, frost weathering in cold regions has always been in focus as a rock deterioration mechanism. Internal stresses, developed by this process, conduce to progressive fracturing and consequent changes in rock properties, particularly, elastic velocities. Previous research was mainly focused on isotropic properties of rocks. However, we have found that elastic anisotropy is substantially enhanced by frost weathering. A series of freeze-thaw tests were performed on weathered rapakivi granite fully saturated by water. The experimental basis involved: a neutron diffraction study of texture, measurements of the 3D distributions of ultrasonic P-wave velocities, and permeability at atmospheric and high confining pressures. Experimental data, along with texture-based effective media modeling of rock elastic properties, revealed the anisotropic response of elastic velocities to freeze-thaw cycling, which is related to the volume increase of specifically oriented cracks. Through permeability measurements, these oriented cracks were determined to be hydraulically interconnected and also responsible for observed frost weathering deterioration. Both ultrasonic and permeability experiments suggested a decrease in the crack closing pressure due to freeze thaw cycling.

中文翻译：

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rapakivi 花岗岩的弹性各向异性、渗透性和冻融循环

摘要 由于冰水过渡，寒冷地区的霜冻风化作为岩石的劣化机制一直受到关注。由该过程产生的内应力导致逐渐破裂和随之而来的岩石特性的变化，特别是弹性速度。以往的研究主要集中在岩石的各向同性特性上。然而，我们发现霜冻风化显着增强了弹性各向异性。对完全被水饱和的风化 rapakivi 花岗岩进行了一系列冻融试验。实验基础包括：质地的中子衍射研究、超声波 P 波速度的 3D 分布测量以及大气和高围压下的渗透率。实验数据，以及基于纹理的岩石弹性属性有效介质建模，揭示了弹性速度对冻融循环的各向异性响应，这与特定定向裂纹的体积增加有关。通过渗透率测量，这些定向裂缝被确定为水力互连，也是观察到的霜冻风化恶化的原因。超声和渗透性实验均表明由于冻融循环导致裂缝闭合压力降低。