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考虑翼形裂纹内渗透压和主裂纹连通部分渗透压对翼形裂纹尖端应力强度因子的影响,建立渗透压-应力作用下岩体压剪翼形裂纹模型,该模型引入翼形裂纹的折算长度l_(eq),将翼形裂纹尖端的应力强度因子K_Ⅰ视为远场应力作用下平直孤立翼形裂纹产生的应力强度因子K_Ⅰ~((1))和等效主裂纹(主裂纹和折算翼形裂纹对组成)产生的应力强度因子K_Ⅰ~((2))之和.针对不同的侧压系数和裂纹渗透压,建立渗透压-应力作用下翼形裂纹有限元分析模型,得出:在高渗透压作用下,随翼形裂纹扩展,翼形裂纹尖端拉应力集中区逐渐增大;侧向拉应力和高渗透压是导致翼形裂纹不稳定扩展的主要因素.通过理论模型和有限元分析对比发现:除翼形裂纹很短的情况外,考虑裂隙渗透压时翼形裂纹理论模型得到的应力强度因子普遍较小,而不考虑渗压时模型解和有限元解误差较少,可以认为理论模型得到的翼裂尖端无量纲应力强度因子与翼形等效裂纹长度关系曲线在走向和量值与有限元解基本上是吻合的.渗透压-应力作用下翼形裂纹模型的建立可为水力劈裂研究和矿井岩溶突水力学机理研究提供理论参考:
Considering the influence of the osmotic pressure in the wing crack and the osmotic pressure of the communicating part of the main crack on the stress intensity factor at the tip of the airfoil crack, an airfoil compression cracked wing crack model under osmotic pressure-stress is established. The converted length of the airfoil crack (eq), the stress intensity factor K_I at the tip of the crack tip is regarded as the stress intensity factor K_Ⅰ ~ (1) and the equivalent primary crack (the main crack and the primary crack) generated by the flat isolated solitary crack under far field stress And the stress intensity factor K_Ⅰ ~ (2) produced by the composition of the wing cracks.The finite element analysis model of the wing crack under the osmotic pressure-stress was established for different lateral pressure coefficient and crack osmotic pressure, Under the condition of high osmotic pressure, with the increase of wing crack, the stress concentration zone at the tip of the wing crack increases gradually. Lateral tensile stress and high osmotic pressure are the main factors leading to the unstable expansion of the wing crack. By theoretical model and finite The results of element analysis show that except for the case of short wing crack, the stress intensity factor obtained by the theoretical model of wing crack is generally small when the seepage pressure of fractures is taken into account, while the error of model solution and finite element solution is less than that of seepage pressure. It can be considered The relationship between the dimensionless stress intensity factor at the tip of the wing and the equivalent wing-length crack length obtained by the theoretical model basically agrees well with the finite element solution. The establishment of the wing crack model under the osmotic pressure-stress can be Hydraulic fracturing research and mine karst water inrush mechanism provide a theoretical reference: