Yalei Zhe, Kepeng Hou, Zongyong Wang, Shifei Yang, Yunlin Yu, Yong Yang
Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming, 650093, China.
Yunnan Yuntianhua Co., Ltd, Kunming, 650228, China.
Sci Rep. 2024 Oct 3;14(1):23029. doi: 10.1038/s41598-024-74583-2.
Slurry retention in fractures decreases after grouting is completed and the pressure supply is stopped, which affects the grouting sealing effect and prevents or restrains the occurrence of such adverse conditions. Based on the time-varying yield stress of grout, a theoretical analysis model of grouting diffusion decay is established, the decay height variation function and the minimum pressure stabilisation time calculation formula are derived, and the sealing mechanism of a jointed rock mass with multiple joints is studied. Moreover, a 3D visualisation laboratory test device for grouting diffusion decay of a jointed rock mass with layers was developed to analyse the diffusion and decay process of grout with different water-cement (W/C) ratios visually, and the correctness of the theoretical model was verified. The results show that: (1) the W/C ratio of grout should not be greater than 2, otherwise it is difficult for grout to remain in the cracks; (2) a large fissure opening easily spreads grout but is not conducive to the retention of grout; and (3) the time of stable pressure determines the retention rate of the slurry in the crack. When the horizontal crack opening width is 3 mm and the W/C ratio of the slurry is 1, the minimum stable pressure time to achieve a better sealing effect is 810 s. The research results can be used to reasonably plan the grouting time and improve the grouting efficiency to ensure the grouting effect, which is crucial for improving the theoretical system of grouting technology.
注浆完成且停止压力供应后，裂隙中的浆液留存率降低，这影响注浆封堵效果，并防止或抑制此类不利情况的发生。基于浆液的时变屈服应力，建立了注浆扩散衰减的理论分析模型，推导了衰减高度变化函数和最小压力稳定时间计算公式，并研究了多裂隙节理岩体的封堵机理。此外，研制了一种层状节理岩体注浆扩散衰减的三维可视化室内试验装置，以直观分析不同水灰比（W/C）浆液的扩散和衰减过程，并验证了理论模型的正确性。结果表明：（1）浆液水灰比不应大于2，否则浆液难以在裂隙中留存；（2）较大的裂隙开度容易使浆液扩散，但不利于浆液留存；（3）压力稳定时间决定了浆液在裂隙中的留存率。当水平裂隙开度为3mm且浆液水灰比为1时，达到较好封堵效果的最小稳定压力时间为810s。研究结果可用于合理规划注浆时间，提高注浆效率以确保注浆效果，这对完善注浆技术理论体系至关重要。
