砂土注浆颗粒流数值模拟研究

Micromechanics Particle Flow Numerical Simulation Research on Soil Grouting

基于流固耦合原理的PFC2D颗粒流数值模拟程序,运用其内置FISHTANK函数库和FISH语言,分别定义流体域的流动方程和压力方程,对灌浆过程中浆液在地层中的扩散过程和形态进行了数值模拟计算。通过调节PFC命令流中的注浆压力p、时步step、水力传导系数perm等参数,对浆液的注浆过程进行了模拟计算。结果表明,灌浆过程中浆液与地基土的作用形式与灌浆压力大小密切相关,过高的注浆压力会对地层结构造成一定的破坏。对钻孔周围土体的应力状态进行了理论推导和分析,理论推导结果与数值模拟结果相符。劈裂灌浆作用发生时,孔隙率和应变率均增加。浆液的渗透性能对高压劈裂灌浆的作用效果不明显。

Based on the principle of fluid-structure coupling numerical simulation program, PFC2D particles flow, which uses its built-in FISHTANK function library and FISH language, and the flow equation and pressure equation of fluid domain have been defined, the process of grouting slurry diffusion in the formation and shape are simulated and calculated. By adjusting the parameter of step and perm in PFC＇s command stream, grouting effects in different penetration gravels are obtained. Numerical simulation indicates that action modes between serous fluid and ground soil are mutually affected by the grouting pressure, and foundation structure will be destroyed as the pressure increase excessively. Stressed states around the drilling hole have been analyzed, its results comply with the simulation. When split grouting method occurs, porosity and strain are increased. Conductivity of the slurry affects the grouting little in high-pressure grouting.