Abstract To enhance the strength and stability of the fine sandy soil in underground engineering construction, a novel chemical slurry was studied. Series of laboratory tests were performed to determine the effect of each component on the rheological properties of grout (e.g. viscosity, gel time and plastic strength). The relationship of the penetrability of grout in sand with different densities was explored by the falling-head permeability test. To assess the performance of cementation, the cemented sand specimens were prepared in the laboratory by hand mixing of grout and loose sand. A range of unconfined uniaxial compression tests, split tensile tests and direct shear tests were performed to determine the effect of several vital factors (e.g. the curing time, grout mix ratio and water content) on the mechanical properties of the cemented sand. As revealed from the results of the experiment, the slurry pertains to Newton fluid in the initial stage, which exhibits lower initial viscosity (2 mPa·s), controllable gel time (5–20 min) and higher plastic strength (35 kPa). In terms of the cemented sand, the maximal cohesion and friction angle is 403.8 kPa and 65°; the biggest compressive strength and tensile strength is 3.68 and 0.37 MPa. The slurry can enhance the strength and stiffness of the loose sand significantly, whereas the degree of improvement is dependent of the grout mix ratio and water content of cemented sand.

中文翻译：

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新型化学浆液及胶结砂力学行为研究

摘要 为提高地下工程施工细砂土的强度和稳定性，研究了一种新型化学泥浆。进行了一系列实验室测试以确定每种成分对灌浆流变特性（例如粘度、凝胶时间和塑性强度）的影响。通过落水头渗透试验，探讨了不同密度砂浆中砂浆渗透性的关系。为了评估胶结性能，在实验室中通过手工混合灌浆和松散沙子制备胶结砂试样。进行了一系列无侧限单轴压缩试验、劈裂拉伸试验和直接剪切试验，以确定几个重要因素（例如固化时间、灌浆混合比和含水量）对胶结砂机械性能的影响。实验结果表明，浆液在初始阶段属于牛顿流体，具有较低的初始粘度（2 mPa·s）、可控的凝胶时间（5-20​​分钟）和较高的塑性强度（35 kPa）。就胶结砂而言，最大内聚力和摩擦角为403.8 kPa和65°；最大抗压强度和抗拉强度分别为3.68和0.37 MPa。浆液可以显着提高松散砂的强度和刚度，而提高的程度取决于水泥砂的灌浆配合比和含水量。最大内聚力和摩擦角为403.8 kPa和65°；最大抗压强度和抗拉强度分别为3.68和0.37 MPa。浆液可以显着提高松散砂的强度和刚度，而提高的程度取决于水泥砂的灌浆配合比和含水量。最大内聚力和摩擦角为403.8 kPa和65°；最大抗压强度和抗拉强度分别为3.68和0.37 MPa。浆液可以显着提高松散砂的强度和刚度，而提高的程度取决于水泥砂的灌浆配合比和含水量。