富水破碎岩体注浆加固实验与机制研究

 采用模拟富水破碎岩体注浆的方法，开展普通硅酸水泥42.5#(PO.42.5)、硫铝酸盐水泥42.5#(SAC.42.5)和自主研发水泥基复合注浆材料(CGM)的注浆加固效果实验。通过对比破碎灰岩和破碎砂岩试样注浆后结石体的单轴压缩实验结果发现，岩体破碎程度越高，注浆后强度改善效果越明显，岩石孔隙率越大，注浆后韧性增强显著。CGM材料对应注浆加固结石体强度显著高于PO和SAC材料，对多孔隙砂岩的刚性改善效果最优，且结石体沿岩–浆界面产生滑移破坏的概率最小，SAC材料次之，PO材料最差。采用扫描电子显微镜测试手段，分析岩–浆界面过渡区域矿物种类及分布形态，揭示了不同水泥类材料注浆效果产生差异的原因，从微观角度确定了岩–浆界面的胶结类型主控因素为岩石的岩性，与水泥材料类型无关。对于致密度高的灰岩类岩石属于Ollivier-Grandet模型，对于多孔隙砂岩类岩石属于Zimbelinan模型。结合对岩–浆界面过渡区域X射线衍射分析和元素扫描分析结果，证明注浆不仅改善岩石的物理力学性能，还会引发岩石组分发生化学变化，在界面区域生成类岩石矿物，可提高岩–浆界面胶结强度。

Grouting reinforcement experiment for water-rich broken rock mass

In this research，the simulation of grouting for water rich and broken sandstones was performed. The ordinary Portland cement #42.5(PO.42.5)，the Sulphatealuminium cement #42.5(SAC.42.5) and the self-developed cement-based composite grouting material(CGM) were applied. Comparison of the uniaxial strengths of samples of broken limestone and sandstone after grouting shows that when the broken degree of rock is higher，the strength improving effect is more obvious，and that the larger the porosity，the better the strengthen improvement. The toughness enhancement of grouted stone is significant. The strengths of CGM strengthened stones are significantly higher than those of PO and SAC materials. The performance improvement of CGM on the porous sandstone is the best. The slippage probability on the surface of CGM and rock is the least. The effect of SAC grouts is better than PO grouts. Scanning electron microscopy was applied to analyze the mineral species and distribution patterns in the interface transition zone of rocks and grouts，which reveals the essence of different grouting effects. The bonding types of the interface between grouts and rocks are mainly determined by the types of rocks. The high-density limestone rocks belong to the Ollivier-Grandet model，and the porous sandstone rocks belong to the Zimbelinan model. The results of X-ray diffraction and scanning elemental analysis show that the grouting can not only improve the mechanical properties of rocks，but also change the chemical composition of rocks. The generated minerals by grouts in the interface zones can improve the bonding strength between the interface of rocks and grouts.