大断面顶推箱涵施工中泥浆套形成机理试验研究

Testing Research on Slurry Sleeve Forming Principle of Large Cross-section Box Culvert

形成良好的泥浆套是大断面箱涵顺利顶进施工的关键。结合某大断面箱涵下穿分离式立交工程实例,设计了模拟试验。对不同土质情况下,正压力、土体含水量及密实度等影响泥浆套形成的因素进行分析。试验证明,最佳注浆压力应为泥浆膜扩散迅速发展的前一级压力,注浆压力随土体密实度增加而增加且与含水量无关,浆液的扩散是劈裂扩散,劈裂压力随土压力增大而增大,约为土压力的2倍。

It is a key factor for large cross-section box culvert to form good slurry sleeves. Simulating tests were designed according to project that a large cross-section box culvert across down a separate interchange. Influence factors of slurry sleeve were analyzed in different soil, including positive pressure, water content and compactness. These tests prove that the best grouting pressure is the pressure just before slurry sleeves rapid diffusion. Grouting pressure increases as soil compactness increases and has no relation with water content. The test also proves that the slurry diffusion is a splitting diffusion, and splitting pressure increases with soil pressure which about two times of soil pressure.