“7”字形半门式架在盾构曲线始发工况下的应用及施工要点

Application and Construction Points of“7”-shaped Half Portal Support Under the Starting Condition of Shield Curve Launching

根据盾构机机身和后配套设备的长度,盾构始发常需要配置约120 m长的车站完整结构。施工过程中由于各种条件的制约,经常会出现不能提供足够长度的车站结构,导致盾构机无法下井的情况。以广州地铁五号线东延段庙头站—夏园站盾构机曲线始发为案例,探讨未完成中板结构工况下的盾构始发方案,提出在地下二层结构侧墙预埋钢板,通过施作“7”字形半门式架及全门式架的支撑体系,确保盾构机实现曲线始发。工程实践证明,该方案能在中板结构未完成的工况下实现盾构机的始发,且可以同步实施中板结构,有效缩短工期。该方案操作简单,适用性强,可为类似工程提供借鉴。

According to the length of the shield machine fuselage and the rear supporting equipment,the shield launching often requires about 120 m long station structure.During the construction process,due to the constraints of various conditions,the station structure often cannot provide sufficient length,resulting in the shield machine cannot go into the working shaft.Taking the curve launching of the shield machine from Miaotou Station to Xiayuan Station in the east extension section of Guangzhou Metro Line 5 as an example,the shield launching scheme under the condition of unfinished middle plate structure is discussed,it is proposed to pre-embed the steel plate steel plate on the underground structure side wall,and construct the support system of the“7”-shaped half portal support and the whole portal support to ensure that the shield machine can realize the curve launching.The engineering practice has proved that the scheme can realize the initiation of shield machine under the unfinished working condition of the middle plate structure,and can simultaneously implement the middle plate structure construction,and shorten the construction period effectively.The scheme is simple and applicable,and can provide reference for similar projects.