Zhang Feng, Liu Jinxiao, He Jiawei, Zhang Kai, Qin Zhongcheng
School of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao, China.
National Demonstration Center for Experimental Mining Engineering Education, Shandong University of Science and Technology, Qingdao, China.
PLoS One. 2025 Aug 18;20(8):e0328492. doi: 10.1371/journal.pone.0328492. eCollection 2025.
As the excavation depth of the tunnel increases, the stress on the surrounding rock increases, and the tunnel becomes fragmented, especially in coal tunnels, which require grouting reinforcement. Conventional materials are inadequate for the grouting and reinforcing demands of this type of surrounding rock; therefore, it is essential to create grouting materials with specific expansion properties. First, the orthogonal test method was employed to optimize the expansion grouting materials ratio. Compared with traditional grouting materials, it exhibits certain expansibility along with good fluidity and strength. Based on a comprehensive evaluation of the mechanical properties of the material, the optimal formulation was determined as follows: 10% UEA expansive agent, 5% early-strength agent, and 1.2% water-reducing agent. Additionally, Through SEM tests and grouting reinforcement test of broken coal or rock, it was found that expansive grouting materials can effectively fill micro-fractures in coal rock, enhance the integrity of the surrounding rock, and improve its mechanical properties. The findings indicate that the recovery strength of coal and rock using expansion grouting materials at 7 days is 0.18 and 0.1 greater than that of pure cement; at 28 days, the recovery strength of coal and rock is 0.27 and 0.15 higher than that of pure cement. Ultimately, the expansion grouting materials is employed in engineering applications. Following the application of anchor grouting and expansion grouting materials, the maximum deformation of the roof at the roadway intersection measures 125 mm, while the maximum deformation on both sides reaches 190 mm. The distortion of the surrounding rock of the roadway is well managed. This is essential for the reinforcement of tunnels within shattered surrounding rock and for the secure extraction of coal in mines.
随着隧道开挖深度增加，围岩应力增大，隧道出现破碎，尤其是煤巷，需要进行注浆加固。传统材料无法满足这类围岩的注浆加固需求；因此，研制具有特定膨胀性能的注浆材料至关重要。首先，采用正交试验法优化膨胀注浆材料配比。与传统注浆材料相比，它具有一定的膨胀性，同时流动性和强度良好。基于对材料力学性能的综合评价，确定最佳配方如下：10%UEA膨胀剂、5%早强剂和1.2%减水剂。此外，通过对破碎煤岩的扫描电镜试验和注浆加固试验发现，膨胀注浆材料能有效填充煤岩中的微裂隙，增强围岩完整性，提高其力学性能。研究结果表明，使用膨胀注浆材料时，煤和岩石在7天的恢复强度分别比纯水泥高0.18和0.1；在28天，煤和岩石的恢复强度分别比纯水泥高0.27和0.15。最终，膨胀注浆材料应用于工程实践。采用锚杆注浆和膨胀注浆材料后，巷道交叉口处顶板的最大变形量为125mm，两侧的最大变形量为190mm。巷道围岩变形得到有效控制。这对于破碎围岩中的隧道加固和煤矿煤炭的安全开采至关重要。
