摘要
以某地铁下穿城市广场工程为研究对象,创新性地在该类地区采用冷冻固结措施;同时总结了地下联络通道冻结固结施工难点,并提出了对应的优化及改进技术措施。冻结加固区位于卵石土地层中,富含地下水,并且渗透系数较大,流速超过冻结法所适用的地下水流速,不利于冻结法加固,易造成冻结帷幕不均匀。因此,在钻孔过程中对渗透性强的地层用膨润土进行冻结孔护壁,同时通过钻孔注水泥浆,以改良土层并减小水流速。通过数值模拟与现场实测可知,在卵石土地层,对沉降要求较高的工程采用冷冻固结法优势明显。
Taking a subway under the city square as the research object,the freezing consolidation measures are innovatively adopted in this kind of area;at the same time,the difficulties of freezing consolidation construction of underground connecting passage are summarized,and the corresponding optimization and improvement technical measures are put forward.The freezing reinforcement area is located in the pebble soil layer,which is rich in groundwater and has a large permeability coefficient.The flow rate exceeds the groundwater flow rate applicable to the freezing method,which is not conducive to the reinforcement of the freezing method and is easy to cause uneven freezing curtain.Therefore,in the drilling process,bentonite is used to freeze the hole wall for the formation with strong permeability,and mud is injected through the drilling to improve the soil layer and reduce the water flow rate.Through numerical simulation and field measurement,it can be seen that in the pebble soil layer,the freezing consolidation method has obvious advantages for projects with higher settlement requirements.
作者
沈春盛
SHEN Chunsheng(East China Regional Headquarters of China Railway Construction Corporation Limited,Hangzhou Zhejiang 310011,China)
出处
《铁道建筑技术》
2022年第5期138-142,共5页
Railway Construction Technology
基金
中铁十二局集团有限公司科技研发计划项目(2019-10)。
关键词
冻结加固
联络通道
富水砂卵石地层
盾构隧道
freezing reinforcement
connecting passage
water rich sandy pebble stratum
shield tunnel
