In this paper the problem of hydraulic fracture in elasto-plastic pressure sensitive material is analyzed. The superdislocation model is used to approximate the plastic deformations in the crack tip area. This model is employed to derive a new crack propagation condition based on the concept of effective fracture toughness. A parametric analysis supported by FEM simulations is conducted to verify the underlying assumptions of the superdislocation model and the resulting crack propagation condition. The results, obtained with the new crack propagation condition for the HF problem, are compared with those produced by a commercial geomechanical FEM package Elfen. The comparison proves the validity of the new crack propagation condition and the proposed modeling approach.

本文对弹塑性压敏材料的水力断裂问题进行了分析。超位错模型用于近似裂纹尖端区域的塑性变形。该模型用于基于有效断裂韧性的概念推导新的裂纹扩展条件。进行了由 FEM 模拟支持的参数分析，以验证超位错模型的基本假设和由此产生的裂纹扩展条件。将使用 HF 问题的新裂纹扩展条件获得的结果与商业地质力学 FEM 软件包 Elfen 产生的结果进行了比较。比较证明了新的裂纹扩展条件和所提出的建模方法的有效性。