水底盾构掘进泥水喷发现象研究

泥水式盾构工法是水底软土隧道施工的首选工法,施工时泥水压力过大可导致开挖面前方地层劈裂,引发泥水喷发、河(海)水倒灌事故。以此类现象为研究对象,研究地层劈裂发生、伸展机制及不同泥水压力对地层劈裂的影响。研究结果表明:水底隧道泥水式盾构施工时,开挖面前方地层微小劈裂纹不可避免,但泥水喷发现象能否发生与盾构掘进参数、泥水性质、地层特性及盾构覆土厚度密切相关,通过理论分析和盾构掘进模型试验,得出了泥水喷发半经验公式,在此基础上提出了防止泥水喷发现象发生的相关措施。

STUDY ON SLURRY-WATER GUSHING DURING UNDERWATER SHIELD TUNNEL CONSTRUCTION

The slurry type shield method is the first choice for submarine soft-soil shield tunnel. If the slurry pressure is too high,it may lead to hydraulic fracturing of stratum in front of open face and cause accident of water gushing. The phenomena described as above,including mechanism of fracturing and the influence of slurry pressure on stratum fracturing,are studied. The achieved results show that,as slurry type shield is driven in submarine stratum,it is inevitable for some tiny cracks to exist in the strata,but the phenomena with/without water gushing has close relation with driving parameter,slurry characteristics,stratum characteristics and overburden thickness. Through theoretical analysis and shield model test,a semi-empirical formula of slurry gushing and anti-gushing method is put forward.