Four failure criteria, a simplified Mohr–Coulomb, a Mohr–Coulomb, a von Mises and a Drucker–Prager model are considered for borehole failure and sand onset predictions. The von Mises is a special case of the Drucker–Prager. The resulting analytical expressions are suitable for implementation in the analytical software for sand onset and sand mass analyses. The models are calibrated and validated against experimental data for hollow cylinder and hollow prism tests on Red Wildmoor sandstone. The analysis shows that a Drucker–Prager model is necessary to capture the experimentally observed effect of axial stress on hole failure. The simplified Mohr–Coulomb model shows no such effect, while the Mohr–Coulomb model shows an effect only at high values of axial stress. The Drucker–Prager model can match satisfactorily the experimental results. It requires, however, the calibration of an additional material parameter which can be done on anisotropic loading hollow prism tests. The models include also a lateral stress anisotropy parameter and a field calibration factor to allow for better approximation of available field or laboratory data.

考虑了四个失效标准，即简化的Mohr-Coulomb模型，Mohr-Coulomb模型，von Mises模型和Drucker-Prager模型，用于井眼破裂和起砂预测。冯·米塞斯（von Mises）是德鲁克-普拉格（Drucker-Prager）的特例。所得的分析表达式适合在沙粒起伏和沙粒质量分析软件中实施。该模型已针对Red Wildmoor砂岩上的空心圆柱体和空心棱镜测试的实验数据进行了校准和验证。分析表明，需要Drucker-Prager模型来捕获实验观察到的轴向应力对孔破坏的影响。简化的Mohr-Coulomb模型没有显示这种效果，而Mohr-Coulomb模型仅在较高的轴向应力下显示了效果。Drucker-Prager模型可以令人满意地匹配实验结果。这个需要，但是，可以在各向异性载荷空心棱镜测试中完成附加材料参数的校准。这些模型还包括横向应力各向异性参数和现场校准系数，以更好地逼近可用的现场或实验室数据。