地铁矿山法隧道装配式二次衬砌配套拼装需求条件研究

Study on Conditions for Prefabricated Secondary Lining Support Assembly of Metro Tunnel Constructed by Mining Method

为解决矿山法隧道内预制二次衬砌拼装面临的空间有限、运输不便、定位困难、隧道自身结构、现浇与拼装接口组合、下井转运、工艺技术等问题,通过采用数值分析、盾构工程类比等方法,结合拼装机工法工艺流程,根据地铁矿山法隧道装配式衬砌环结构条件,研究撑靴式和机械手式拼装机2套设备及其技术需求条件,实现隧道初期支护轮廓内的衬砌片机械化拼装。主要结论如下:(1)撑靴式拼装机能够提供衬砌片的持续压紧,而设备撑靴需要作用于初期支护结构上,要求初期支护结构承载力不得低于150 kPa;(2)机械手式拼装机需要借助衬砌环间螺栓实现衬砌片的纵向压紧,对于300 mm厚的衬砌片,在螺栓轴力达到25 kN时,衬砌片环间可达到防水要求;(3)独立设置的拼装机吊装竖井净空尺寸一般可取4.6 m×6.7 m;(4)对于地铁暗挖区间的非标准断面,需采用现浇方法先行施作,以保证拼装与现浇结构衔接,同时保证拼装机可顺利通过;(5)可借助提前施作定位导台的方式,实现拼装环的精准定位。

To solve the problems encountered during the assembly of prefabricated secondary lining of mined metro tunnel in terms of limited space,inconvenient transportation,difficult positioning,tunnel structure,joint between precast and cast-in-situ structure,transportation in a shaft,and construction technology,two suits of equipment,a gripper-type and a manipulator-type assembling machine and their technical demands,are investigated using numerical analysis and shield-engineering analogy method.The construction technology of the assembling machine and structural conditions for the prefabricated lining ring are presented.The mechanical assembly of the lining ring in a primary support inner contour is realized.The main conclusions are as follows:(1)The gripper-type assembling machine can continuously keep the lining ring in a compaction state.The gripper should act on the primary support structure;thus,the bearing capacity of the primary support should not be less than 150 kPa.(2)The longitudinal compaction state of the lining ring can be achieved by the manipulator-type assembling machine with the help of lining ring bolts.The waterproof of 300-mm thick lining rings can be realized when the axial force of bolt reaches 25 kN.(3)The independent hoisting shaft for the assembling machine should be used,and the clearance size generally can be 4.6 m×6.7 m.(4)For the nonstandard cross-section of the underground metro section,the cast-in-situ method should be employed first;then the assembled structure should be well-connected to the cast-in-situ structure,thereby ensuring smooth passage of the assembling machine.(5)The accurate positioning of the assembled ring can be realized using a positioning guide in advance.