流塑状淤泥层及饱和砂层浅埋盾构掘进技术

Tunneling Technology of Shallow Shield in Flow Plastic Silt Layer and Saturated Sand Layer

东莞市轨道交通1号线道滘东站—人民医院站区间盾构隧道覆土浅,洞身位于全断面流塑状淤泥层、饱和砂层中,富含承压动水,地面建筑和地下管线较多,盾构掘进风险高。结合该工程实践,介绍在多风险叠加工况下,盾构始发、接收、掘进的主要对策及关键技术。洞门坍塌、盾构喷涌、盾构栽头、隧道上浮、地面隆起,是该工程的主要风险。采用钢套筒始发技术、配置双螺旋输送器及主动铰接、调整推进千斤顶布置及盾构机重心、上坡超压掘进等关键措施,保障盾构机连续均衡掘进、推进轴线及地面沉降(或隆起)在规范允许范围内。

The shield tunnel between Daojiao East Station and People's Hospital Station of Dongguan Rail Transit Line 1 is covered with shallow soil,and the tunnel body is located in the full face flow plastic silt layer and saturated sand layer,which is rich in confined dynamic water,with many buildings on the ground and pipelines underground.Therefore,the shield tunneling risk is high.In combination with the implementation of the engineering project,this paper introduces the main countermeasures and key technologies of shield launching,receiving and tunneling under multi-risk conditions.The main risks of the Project include portal collapse,shield gushing,shield heading,tunnel floating and ground uplift.Key measures such as use of steel sleeve launching technology,configuration of double screw conveyor and active articulation,adjustment of thrust jack layout and center of gravity of shield machine,and upslope overpressure tunneling are put forward to ensure that the continuous and balanced tunneling of shield machine,thrust axis and ground settlement(or uplift)are within the allowable range of the specification.