摘要
高渗透性富水砂层条件下,端头井水泥系加固质量控制、盾构进出洞防渗漏动态控制与涌水涌砂时现场应急处置等方面的研究有较为重要的现实意义;根据现场实际合理评估施工风险,采取合理风险预控措施尤为重要。6类施工方案的实践表明,高渗透性富水砂层条件下,以洞门帘布橡胶+折页板为代表的简单防渗漏措施不能完全满足施工安全需要。高渗透性富水砂层条件下,降水是关键,洞口段增设管片注浆环、端头井提前施作应急注浆孔等应急处置措施不可缺少。在降水效果、端头加固质量无法保证的条件下,地下2层车站的盾构进出洞施工采用短套筒+盾尾刷/弹簧钢板类的止水措施较为经济适用,地下3层及以上车站的盾构进出洞施工采用钢套筒+冻结法施工较为安全,但采取水平冻结还是垂直冻结方式视现场情况而定。采用增设气囊等新型止水措施也可取得较好止水效果,但无论采取何种措施,均应加强安全防护措施施工质量管控。
Under the condition of high permeability water-rich sand strata,the research on the quality control of cement system reinforcement of the work well,the dynamic control of leakage prevention of the shield departure and reception,and the on-site emergency disposal in case of water and sand gushing has more important practical significance.It is particularly important to reasonably assess the construction risks according to the actual situation on site and take reasonable risk pre-control measures.The practice of 6 types of construction schemes shows that under the condition of high permeability water-rich sand strata,the simple anti-leakage measures represented by portal rubber ply+hinged slabs cannot fully meet the needs of construction safety.Under the conditions of having a high-permeability water-rich sand strata,precipitation is the key,and emergency measures such as adding grouting rings for segments at the entrance of the tunnel and constructing emergency grouting holes in advance in work well are indispensable.Under the condition that the precipitation effect and the quality of work well reinforcement cannot be guaranteed,it is more economical and practical to use the short sleeve+shield tail brush/spring steel plate for the shield departure and reception construction of the 2nd floor underground station.It is safer to use the steel sleeve+freezing method for the construction of the shield departure and reception on the 3rd floor underground or above,but the horizontal freezing or vertical freezing method depends on the site conditions.New water-stopping measures such as adding airbags can also achieve better water-stopping effects,but no matter what measures are taken,safety protection measures should be strengthened to control construction quality.
出处
《现代城市轨道交通》
2022年第10期49-53,共5页
Modern Urban Transit
关键词
城市轨道交通
高渗透性
富水砂层
盾构
进出洞
urban rail transit
high permeability
water-rich sand strata
shield
departure and reception
