摘要
西安地铁2号线北端盾构施工过程中全断面穿越中砂、粗砂层,其中中砂的标贯击数达到150击,砂层极为密实,且需严格控制地面沉降;盾构掘进出现极限参数,不能正常运转,同时螺旋、刀盘甚至是盾体磨损加快。通过增加开挖面积、主动铰接辅助推进、渣土改良、压缩空气辅助建压等措施来解决超密实地层盾构掘进问题,使用效果比较明显,提高了土压平衡盾构对密实砂层的适应性。
Since the north end of Line Two of the Xi'an Metro has to full-cross-section run through the medium-size sand and coarse sand stratum with a shield,where the SPT blow count for medium-size sand reaches 150,the sand stratum being extremely dense,the ground settlement needs to be strictly controlled;in such a case,the limits of parameters emerge in the middle of the shield-drilling,the shield can′t work properly,with the spiral and the cutter-holder,or the body of the shield itself,worn faster.The problem of a shield drilling through an extraordinarily dense stratum is solved by means of increasing the excavation area,using active hinges to assist drilling,modifying the muck,using compressed air to help pressure buildup and other measures.The effects of applying these measures are comparatively obvious,with the adaptability of the earth-pressure-balancing shield to dense sand strata improved.
出处
《国防交通工程与技术》
2016年第5期23-25,39,共4页
Traffic Engineering and Technology for National Defence
关键词
密实砂层
中砂
标贯击数
盾构
渣土改良
建压
dense sand layer
medium-sized sand
SPT blow count
shield
modification of muck
pressure buildup