Dry snow slab quasi‐brittle fracture initiation and verification from field tests
Dry snow slab quasi‐brittle fracture initiation and verification from field tests
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干雪板准脆性断裂引发及现场试验验证
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
D. Mcclung
中科院分区：
文献类型：
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作者：
D. Mcclung
[1]干雪板雪崩起源于粘性雪平面板下的薄的软弱层中的剪切断裂。本文分析了400多个雪剪切断裂试验的现场数据，并将其应用于雪板释放和雪包不稳定性评价问题。本文包含一个新的，但简单的，分析模型来估计断裂的临界长度。该模型包含一个有限的断裂过程区的假设，这可能是一个显着的分数板深度D或弱层剪切断裂的临界长度L。结果表明，比L/D是1阶的数据和模型，如先前预测的雪板。结合实验室试验的实验结果，两组现场数据和新的模型，表明，以前的理论论点雪板释放近30年的现场数据是一致的。简单的扩展解释粘弹性温度效应和边坡法向软弱层变形对雪板失稳的影响。由于试验现场数据包含粘弹性效应和边坡法向效应，因此必须在模型中考虑这些效应，并进行雪板不稳定性评估。
[1] Dry snow slab avalanches initiate from shear fracture in a thin weak layer underneath a planar slab of cohesive snow. In this paper, field data from more than 400 snow shear fracture tests are analysed and applied to the problem of snow slab release and snow pack instability evaluation. The paper contains a new, but simple, analytical model to estimate the critical length for fracture. The model contains the assumption of a finite fracture process zone which may be a significant fraction of the slab depth D or the critical length L for weak layer shear fracture. The results suggest that the ratio L/D is of order 1 for both the data and the model as previously predicted for the snow slab. Using a combination of experimental results from laboratory tests, two sets of field data and the new model, suggests that previous theoretical arguments about snow slab release over almost 30 years are congruent with the field data. Simple extension to explain viscoelastic temperature effects and slope normal weak layer deformation on snow slab instability evaluation is included in the analysis. Since the experimental field data contain viscoelastic effects and slope normal effects, it is imperative to account for these in the model and for snow slab instability evaluation.