富水圆砾地层盾构短套筒接收施工关键技术

富水圆砾地层因其含水量高、渗透系数大、化学注浆加固成形率差,增加了盾构接收进洞的施工难度。以南宁轨道交通1号线10标白苍岭—火车站站区间盾构接收进洞施工为例,运用"接长补短"理念,创新性地提出盾构短套筒接收施工工艺。在洞门环板前端通过增加短套筒的方式延长盾构机接收长度,使盾构机接收位置前移,盾构机在短套筒的保护下能够完全进入端头加固区,结合对盾构机主机尾部已脱出盾尾的管片二次注浆封堵或者地面降水措施,保证在盾构机接收过程中端头加固体内部水系与外界处于隔离状态,确保盾构机在接收过程中不发生涌水、涌砂,达到安全接收的目的。

Key Technology of Short Sleeve Shield Reception in Water-rich Gravel Stratum

The water-rich gravel stratum is characterized by high water content,large permeability coefficient and poor rate of chemical grouting reinforcement,which increases the difficulty of construction during the departure and reception of shield.The author takes shield reception between Baicangling and Nanning Railway Station as an example and puts forward the innovative construction technology for short sleeve shield reception.In the front end of the hole ring,the short sleeve is installed to extend the length of the shield reception distance.Under the protection of the short sleeve,the whole shield can be completely put into the reinforcement area.By the grouting at the tail of the shield or the engineering dewatering measures,the water can be isolated from the outside,which can reduce the risk of quicksand and water gush during the process of shield reception.