基于RFPA^(2D)的含裂隙灌浆帷幕体渗透损伤演化规律

Permeability Damage Evolution Rules Based on RFPA^(2D) for the Grouting Curtain Body Containing Fissures

以某石灰石矿涌水治理工程为背景,基于RFPA^(2D)-Flow软件,建立不同加载方案下的含45°狭长椭圆裂隙的灌浆帷幕体二维平面应变数值模型,分析了轴压、围压及渗透水头差等因素对含裂隙灌浆帷幕体作用的损伤演化规律。结果表明:在轴向加载作用下,裂隙灌浆帷幕体的裂纹发生在裂隙尖端附近,且裂隙倾角与初始裂隙呈垂直扩展、延伸直至贯通破坏,破坏形式呈径向拉裂破坏;在围压加载作用下,裂隙灌浆帷幕体的裂纹萌生同样发生在裂隙尖端附近,但围压加载的破坏裂隙是沿轴向扩展、延伸贯通的;渗透水头差对裂隙灌浆帷幕体的水压致裂形式与轴向加载的形式较为相近,都是径向贯通破坏,不同之处在于渗透水头差造成的破坏呈现为初始裂隙范围内径向粉碎性贯通破坏。

Taking the water treatment project of a limestone mine as the background,a two-dimensional strain numerical model of grouting curtain,based on RFPA2d-Flow software,with45degrees of narrow elliptical fissures under different loading scenarios,has been thus established.An analysis has been made of the damage evolution rules for the axial pressure,confinement pressure as well as the seepage water head difference.The experimental results show that:under the effect of axial loading,the crack tip near the crack initiation occurs in the grouting curtain body which contain fissures,with the fracture angle and the initial fracture vertically extended until the failure of coalescence,characterized with radial tensile fractures;under the action of confining pressure,the crack initiation of fractured grouting curtain occurs near the crack tip,with the fracture under confining loading extending along and through the axial direction;the hydraulic fracturing in the form of grouting curtain body,which is caused by infiltration energy,is relatively similar in form to the axial loading,both with coalescence failures;what makes them different is that the damage by infiltration energy is all to pieces within the scope of the initial cracks.