F1离子固化剂加固泥岩物理力学特性试验

Physical and Mechanical Properties Experiment of Solidified Mudstone by F1 Ionic Soil Stabilizer

泥岩具有吸水膨胀软化、失水收缩干裂和易崩解等不良工程特性,经常诱发路基上拱、边坡坍塌、渠坝和建筑物开裂等工程病害。为消除泥岩的不良特性,采用F1离子固化剂对泥岩进行改良试验研究,对不同F1掺量的固化泥岩试样开展无荷膨胀试验、三轴不固结不排水试验、冻融循环试验、核磁共振试验和X射线衍射(X-ray diffraction,XRD)衍射试验,对F1加固泥岩的物理力学特性、微观孔隙结构和矿物成分展开研究。结果表明:F1固化剂通过离子交换作用和磺化油疏水作用,显著改善了泥岩土的水敏性和压实特性,降低了渗透性和膨胀性;在泥岩中加入0.5 L/m^(3)(最佳掺量)的F1固化剂后,其破坏应力提升1.97倍,摩擦角和黏聚力分别增大1.29倍和1.64倍,且冻融循环次数对F1固化泥岩土样黏聚力和摩擦角的影响较小;分析核磁共振试验与XRD衍射试验结果可知,F1固化剂作用前后,泥岩中并无新物质生成。掺入F1固化剂后,泥岩土样中的大、中、小孔隙数量减小,孔隙总体积降低,土体密实度提升。

Mudstone has unfavorable engineering characteristics such as water absorption expansion softening,water loss shrinkage,dry cracking and easy disintegration,which often induces engineering diseases such as subgrade arching,slope collapse,canal dam and building cracking.In order to eliminate the bad characteristics of mudstone,F1 ionic soil stabilizer was used to improve mudstone.The no-load expansion test,triaxial unconsolidated undrained test,freeze-thaw cycle test,nuclear magnetic resonance test and X-ray diffraction(XRD)test were carried out on the solidified mudstone samples with different F1 content.And the physical and mechanical properties,micro pore structure and mineral composition of F1 reinforced mudstone were studied.The results show that F1 ionic soil stabilizer significantly improves the water sensitivity,compaction characteristics of mudstone soil and reduces the permeability and expansibility through ion exchange and hydrophobic action of sulfonated oil.After adding 0.5 L/m^(3)(the best content)of F1 ionic soil stabilizer into mudstone,the failure stress is increased by 1.97 times,the friction angle and cohesion are increased by 1.29 times and 1.64 times.What’s more,the frequency of freeze-thaw cycles has little effect on the cohesion and friction angle of F1 improved mudstone sample.The results of nuclear magnetic resonance test and XRD diffraction test show that there is no new material in mudstone before and after adding F1 ionic soil stabilizer.After adding F1 ionic soil stabilizer,the number of large,medium and small pores in the mudstone soil samples are decreased,the total pore volume is decreased,and the compactness of soil mass is increased.