Slurry grouting plays an important role in water plugging for hydrogeological engineering and there are multiple factors that restrict the slurry flow. This study investigates the restriction mechanisms, based on a single inclined rough fracture, employing a space stepwise method (SSM) using multi-direction sectors (MDS) for calculating the diffusion of variable-viscosity slurry under constant flow. The specifically developed numerical algorithm is validated by experimental results. The spatio-temporal effects of major factors on the flow, and the rock hydraulic properties, were analyzed for cement-based slurry. The results show that the slurry flow calculated by MDS-SSM exhibits strong fitting with experimental results. The diffusion pattern no longer exhibits a circular plane, but rather a double semi-elliptical distribution. The fracture direction angle, especially for the upward vertical flow, must be considered in the case of a larger dip angle. The main controlling factor of the pressure field is the higher slurry viscosity in regions far from the injection hole, and the influence of dip angle is significantly greater closer to the hole. Roughness has an influence on the fracture hydraulic properties, and the required grouting pressure increases with an increase in roughness. The fracture aperture, viscosity coefficient, and diffusion radius are three key factors with strong sensitivity affecting the forecasting accuracy of grouting parameters. The role of the fracture dip angle can be neglected only in narrow fractures and long-distance diffusion with higher-viscosity slurry or larger pressure. The key threshold value can be obtained with a fitting formula under given conditions.

泥浆灌浆在水文地质工程的堵水中起着重要作用，并且有多种因素限制了泥浆的流动。这项研究研究了基于单倾斜粗糙裂缝的约束机制，采用空间逐步方法（SSM）和多方向扇形（MDS）来计算恒定流量下可变粘度浆料的扩散。实验结果验证了专门开发的数值算法。分析了水泥基泥浆的主要时空因素对流量的时空影响以及岩石的水力特性。结果表明，利用MDS-SSM计算得到的泥浆流与实验结果具有很好的吻合性。扩散图案不再呈现圆形平面，而是呈现双半椭圆形分布。在较大倾角的情况下，必须考虑断裂方向角，特别是对于向上的垂直流。压力场的主要控制因素是在远离注入孔的区域中较高的浆料粘度，并且靠近注入孔的倾角的影响明显更大。粗糙度对裂缝的水力性能有影响，并且所需的灌浆压力随粗糙度的增加而增加。裂缝孔径，黏度系数和扩散半径是影响灌浆参数预测精度的三个关键因素，敏感性强。裂缝倾角的作用只能在高粘度浆液或较大压力下的狭窄裂缝和长距离扩散中被忽略。