Cement–sodium silicate (C–S) slurry has been widely used to prevent water inrush during the construction of submarine tunnels. The diffusion mechanism of C–S slurry in seawater is still unknown. In this study, a series of contrast and orthogonal tests was conducted using a visual fracture grouting device to investigate the effects of the initial flowing water speed, seawater content, grouting rate, roughness, and aperture width of rock fractures on the propagation patterns and sealing effect. The contrast test results showed that seawater has a significant impact on slurry diffusion and fracture sealing. The orthogonal test results indicated that the propagation patterns can be classified into four types according to the experimental results: (1) complete sealing without cavities or water flow channels; (2) incomplete sealing with large cavities but no water flow channels; (3) partial sealing with water flow channels along both sides of the fracture; and (4) failed sealing with obvious water flow channels composed of many cavities. The descending order of factors on the sealing effect was as follows: initial water flow speed, seawater content, aperture width, roughness, and grouting rate. Moreover, the influences of these factors on the sealing effect were revealed. The sealing effect increased with the seawater content and grouting rate, and decreased with the initial flowing water speed, roughness, and aperture width. The results contribute to the understanding of the grouting diffusion mechanism and the design of grouting treatments for water inrush in submarine tunnels to reduce the risk of tunnelling.

中文翻译：

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水泥-硅酸钠浆液在流动海水岩石裂缝中的密封效果试验研究


水泥-硅酸钠 （C-S） 浆料已被广泛用于防止海底隧道施工过程中的突水。C-S 浆料在海水中的扩散机制仍然未知。本研究采用目视裂缝注浆装置进行了一系列对比和正交试验，研究了岩石裂缝初始流速、海水含量、注浆速率、粗糙度和孔径宽度对岩石裂缝扩展模式和密封效果的影响。对比试验结果表明，海水对浆液扩散和裂缝密封有显著影响。正交试验结果表明，根据实验结果，传播模式可分为四种类型：（1） 完全密封，无空腔或水流通道;（2） 密封不完全，空腔大，但无水流道;（3） 沿裂缝两侧用水流通道进行部分密封;（4） 密封失败，由许多空腔组成的明显水流通道。影响密封效果的因素从大到小依次为：初始水流速度、海水含量、孔径宽度、粗糙度和注浆速率。此外，揭示了这些因素对密封效果的影响。封堵效果随海水含量和注浆速率的增加而增加，随初始流水速度、粗糙度和孔径宽度的增加而降低。研究结果有助于理解注浆扩散机制和海底隧道突水注浆处理的设计，以降低隧道掘进的风险。