作　　者： ; ;

机构地区： 湖南科技大学能源与安全工程学院

出　　处： 《爆炸与冲击》 2012年第4期423-431,共9页

摘　　要： 由于单轴荷载下饱水岩石的动态力学特性与静态力学特性存在很大差异,从宏观上进行力学分析存在局限性。根据岩石受压全应力应变曲线的细观机制,分析了静态及动态单轴荷载条件下孔隙水影响饱水岩石裂纹扩展的情况。在静态单轴压缩条件下,初始裂隙受压使自由水产生孔隙水压力,自由水对翼裂纹有向外挤压的应力,促进裂纹扩展。在动态单轴压缩条件下,自由水会产生粘结力,抑制裂纹扩展。根据翼裂纹受压扩展原理,推导出饱水单轴条件下动态抗压强度、静态抗压强度的计算公式,在相同断裂韧度下,饱水岩石静态抗压强度<风干岩石静态抗压强度<饱水岩石动态抗压强度。对自然风干和饱水砂岩进行单轴静态、动态压缩实验,结果与理论模型的结果相符。 Dynamic mechanical properties of water-saturated rock under uniaxial load are highly different from its static mechanical properties,the reasons of which can not be explained well based on macro-mechanics.According to meso-mechanism of rock complete stress-strain curve under uniaxial compression,crack propagation of water-saturated rock influenced by pore water under dynamic load is analyzed as well as under static load.When initial fractures are subjected to static uniaxial compression load,it can cause free water to appear pore water pressure,which can promote the expansion of winged crack due to its extruding winged crack outwards.In the condition of dynamic uniaxial compression loads,free water appear cohesive force to hinder the propagation of winged crack.Based on compressive wing crack propagation mechanism,calculation formulas of static compressive strength and dynamic compressive strength with water under uniaxial load are obtained.With the same fracture toughness,static compressive strength of water-saturated rock is even lower than that of dry rock.Both of them are lower than dynamic compressive strength of water-saturated rock.Static and impact compressive experiments on air-dried and water-saturated sandstone are conducted,the experiment results are in agreement with the ones from theoretical models.

关 键 词： 固体力学 动态抗压强度 细观力学 饱水岩石 裂纹扩展

领　　域： [理学] [理学]