冻结井高强混凝土损伤演化与渗透性关系

Relation between Damage Evolution and Permeability of High-strength Concrete of Freezing Shaft Lining

以冻结井高强混凝土为研究对象,通过混凝土三轴压缩受力全过程渗透性试验,研究混凝土力学损伤演化与渗透性关系。结果表明：混凝土在压缩应力作用下的损伤演化与结构内部微裂隙的扩展发育有关;通过间接测量法即测量微观损伤的宏观表现来量化损伤,以环向应变作为宏观表现形式定义新的损伤变量,提出相应的损伤本构方程;分析围压、损伤变量、主应力差与混凝土渗透性之间的关系;运用数理统计中回归分析方法给出反映混凝土渗透性与围压、损伤的相关经验公式。

The damage evolution of concrete under compressive stress condition and its impact on concrete permeability were investigated via a series of hydro-mechanical triaxial coupling tests on high-strength concrete of freezing shaft lining specimens under different confining pressures using triaxial servo-controlled seepage equipment. The experimental results show that the damage evolution of concrete under compression stress is related to internal micro-porous structure and the development and expansion of the cracks. The damage evolution was measured indirectly. The damage factor is defined by circumferential strain on specimens, and a damage constitutive relationship was proposed. The relationships among the confining pressure, damage factor, principal stress deviator and permeability of concrete were established. Furthermore, the relation between permeabilities of concretes relevant to pressure and damage evolution can be described by an empirical formula obtained based on linear regression.