Yu Xiao, Cao Yajun, Tian Fubing, Chen Chaowei, Chen Chao, Wang Wei, Jiang Yaru
Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210024, China.
Materials (Basel). 2025 Jul 3;18(13):3155. doi: 10.3390/ma18133155.
In pipe jacking construction, thixotropic slurry critically governs lubrication, friction reduction, and ground support. This study evaluated slurry performance through six parameters: specific gravity (SG), pH, fluid loss (FL), water separation rate (WSR), filter cake thickness (FCT), and funnel viscosity (FV). Orthogonal experiments optimizing bentonite, carboxymethyl cellulose (CMC), and sodium carbonate (NaCO) ratios established 10 wt.% bentonite, 0.3 wt.% CMC, and 0.4 wt.% NaCO as the optimal formulation. Subsequently, to address performance limitations in challenging conditions, this study introduces hydroxyethyl cellulose (HEC) as a novel additive, with potential advantages under high-salinity and variable pH conditions. Comparative experiments demonstrated that HEC, as a non-ionic water-soluble cellulose, not only significantly increases FV and reduces FL while maintaining SG, FCT, and WSR within acceptable thresholds, but also exhibits superior pH stability compared to CMC. Based on the aforementioned results, interface friction characterization tests were conducted on representative slurry formulations with varying FVs, quantitatively demonstrating the viscosity-dependent friction-reduction performance. Complementary scanning electron microscopy (SEM) analysis of three distinct thixotropic slurry compositions systematically revealed their microstructural characteristics, with microscopic evidence confirming the excellent compatibility between HEC and thixotropic slurry matrix. These findings highlight HEC's potential as an effective alternative in pipe jacking, particularly in demanding geological environments.
在顶管施工中，触变泥浆对润滑、减摩和地层支护起着关键作用。本研究通过六个参数评估泥浆性能：比重（SG）、pH值、失水量（FL）、析水率（WSR）、滤饼厚度（FCT）和漏斗粘度（FV）。通过优化膨润土、羧甲基纤维素（CMC）和碳酸钠（NaCO）比例的正交试验，确定了10 wt.%膨润土、0.3 wt.% CMC和0.4 wt.% NaCO为最佳配方。随后，为了解决在具有挑战性条件下的性能限制，本研究引入羟乙基纤维素（HEC）作为一种新型添加剂，其在高盐度和可变pH条件下具有潜在优势。对比试验表明，作为一种非离子型水溶性纤维素，HEC不仅显著提高了FV并降低了FL，同时将SG、FCT和WSR保持在可接受的阈值范围内，而且与CMC相比还表现出优异的pH稳定性。基于上述结果，对具有不同FV的代表性泥浆配方进行了界面摩擦特性测试，定量证明了粘度依赖性的减摩性能。对三种不同触变泥浆成分进行的补充扫描电子显微镜（SEM）分析系统地揭示了它们的微观结构特征，微观证据证实了HEC与触变泥浆基质之间具有优异的相容性。这些发现突出了HEC作为顶管施工中一种有效替代品的潜力，特别是在苛刻的地质环境中。
