【作者】 王斌；

【导师】 王连国；

【作者基本信息】 中国矿业大学 ， 一般力学与力学基础， 2019， 硕士

【摘要】 充填水泥浆对于加固裂隙岩石,维护破裂围岩稳定具有重要的理论和工程意义,尤其是超细水泥的高耐久性、高强度等优良特性对破裂围岩控制具有明显的效果。本文通过自行设计的直剪试验系统开展了一系列不同粒径的充填水泥浆裂隙岩石剪切力学试验,结合声发射监测以及电镜扫描技术分析了充填水泥浆裂隙岩石宏观破裂演化规律及细观结构分布特征。并通过水泥浆液充填裂隙岩石流动性试验研究了不同粒径对浆液流变参数的影响,以实现水泥浆液在裂隙岩体中的流动可行性。取得成果如下:(1)制备了粗糙度适中的红砂岩裂隙试样,通过自行设计的直剪试验系统,进行了充填不同类型水泥浆红砂岩裂隙岩石的直剪试验研究,并利用声发射监测系统对剪切过程中的声发射信号进行监测,研究成果表明充填三种类型水泥浆裂隙岩石的剪切应力-剪切应变曲线形态基本一致,均无明显峰值。在相同法向应力作用下,充填超细水泥裂隙岩石剪切强度、剪切刚度、粘聚力等力学参数均有了明显的提高。(2)通过高清CCD相机实时观测充填水泥浆裂隙岩石破裂过程,探讨了不同粒径充填水泥浆裂隙岩石宏观破裂演化规律与破坏形态,结果发现在剪切破坏过程中岩壁-浆液结石接触面首先开始分离,随着剪切变形的进一步增加,水泥结石体逐渐被剪断。并通过电镜扫描研究了不同粒径水泥结石体及浆-岩界面细观结构特征。结果发现超细水泥在结石体和界面过渡区与普通水泥相比,孔洞和缺陷数量均明显减少,结构更加密实,结构整体性更好。(3)开展了水泥浆液充填裂隙岩石流动可行性试验研究,结果表明超细水泥浆液I、II的表观粘度整体上高于普通水泥浆液,而且三种水泥浆液的表观粘度随着减水剂掺量的增加呈先减小后增大的趋势。并根据Bingham模型分析了水泥浆体屈服应力和塑性粘度等流变参数随减水剂掺量变化规律。更多还原

【Abstract】 Filling cement slurry has important theoretical and engineering significance for strengthening fractured rock and maintaining the stability of fractured surrounding rock.Especially,the excellent characteristics of ultra-fine cement,such as high durability and high strength,have obvious effect on controlling fractured surrounding rock.In this paper,a series of shear mechanics tests of fissured rock filled with cement slurry with different particle sizes were carried out by a self-designed direct shear test system.The macro-fracture evolution law and micro-structure distribution characteristics of fissured rock filled with cement slurry were analyzed by acoustic emission monitoring and scanning electron microscopy.The influence of different particle sizes on the rheological parameters of grout is studied through the fluidity test of fissured rock filled with cement slurry,so as to realize the feasibility of the flow of cement slurry in fissured rock mass.The results are as follows:(1)Fissure samples of red sandstone with moderate roughness were prepared.The direct shear test of filling different types of cement mortar red sandstone fissure rocks was carried out by self-designed direct shear test system.The acoustic emission signals during shear process were monitored by acoustic emission monitoring system.The research results show that the shear stress-shear displacement curves of filling three types of cement mortar fissure rocks are different.The line shape was basically the same,and there was no obvious peak value.Under the same normal stress,the shear strength,shear stiffness,cohesion and other mechanical parameters of rock filled with ultra-fine cement fissures have been significantly improved.(2)Through real-time observation of fracture process of filling cement slurry fissure rock by high-definition CCD camera,the macro-fracture evolution law and failure mode of filling cement slurry fissure rock with different particle sizes are discussed.It is found that the interface between rock wall and slurry stones begins to separate first in the process of shear failure.With the further increase of shear deformation,the cement stones are gradually sheared.The micro-structure characteristics of cement stone body and magma-rock interface with different particle sizes were studied by scanning electron microscopy.The results show that the number of holes and defects in the superfine cement in the transitional zone between the stone body and the interface are significantly reduced,the structure is more compact and the integrity of the structure is better than that in the ordinary water.(3)The feasibility study on the flow of fissure rock filled with cement slurry is carried out.The results show that the apparent viscosity of superfine cement slurry I and II is generally higher than that of ordinary cement slurry,and the apparent viscosity of three kinds of cement slurry decreases first and then increases with the increase of water reducer content.Based on Bingham model,the variation of rheological parameters such as yield stress and plastic viscosity of cement paste with water reducer content was analyzed.更多还原