黄土盾构隧道膨润土泥浆渣土改良技术研究

为了解决黄土地层中土压平衡盾构施工地铁区间隧道时出现的出土困难、土仓压力难以建立以及刀具温度过高等问题,采用膨润土、泡沫对渣土进行改良才能保证盾构掘进效果。采用正交试验法进行了膨润土泥浆优化试验与泡沫优化试验。通过膨润土泥浆优化试验找到了适合黄土地层的膨润土改良剂及膨润土泥浆的最优体积分数。通过泡沫优化试验找到了泡沫性能与发泡剂溶液最佳体积分数的关系,本文研究成果在实际工程中得到了成功应用,以期为类似工程提供借鉴与参考。

Study on Grounding Conditioning by Bentonite Slurry in Shield Tunneling in Loess Strata

When EPB shield bores in loess strata, the muck conveying is difficult, the pressure in the excavation cham ber is difficult to be established and the temperature of the cutting tools is very high. In this case, ground conditioning by grounding conditioning agents, such as bentonite, is needed so as to ensure successful shield boring. Bentonite slurry optimization test and foam optimization test are made by means of orthogonal test. The optimum concentration of the ben tonite conditioning agent and bentonite slurry suitable for loess strata is obtained by means of bentonite slurry optimization test; the relationship between the foam performance and the optimum concentration of the foaming solution is obtained by means of foam optimization test. The paper can provide reference for similar projects in the future.