摘要
超前模筑衬砌法的基本思想是将外层衬砌结构分解成多个小断面并进行钢管顶进,通过切割、焊接,形成一个封闭的衬砌模板。在模板内浇筑混凝土,形成衬砌结构,可实现软弱地层中的大断面快速开挖。结合某地铁站的超前模筑衬砌法设计施工,对顶管直径、壁厚、间距以及顶力等参数进行研究分析(采用有限元软件MIDAS-GTS建立数值计算模型),得出如下研究成果。(1)顶管管径:应根据施工地质条件、设备要求、结构断面、周边环境条件及工程造价等进行综合分析,在满足施工空间(一般不小于2 m)及结构尺寸要求的前提下,宜尽量减小。(2)顶管壁厚:应根据顶进和切割的施工顺序、地质条件及有限元数值模拟成果综合确定(一般要求不大于1%管径)。(3)顶管间距:按照土拱效应理论计算最大的顶管间距,结合施工空间要求,合理确定顶管间距。(4)顶管顶力:可按照施工工序,按顶管外侧摩阻力即为顶力的原则进行计算。
The basic idea of advanced form lining method is to decompose the outer lining structure into several small sections for steel pipe jacking,and form a closed lining formwork by cutting and welding.Pouring concrete in the formwork to form the lining structure can realize the rapid excavation of large section in soft stratum.Combined with the design and construction of a metro station with advanced form lining method,the parameters such as jacking pipe diameter,wall thickness,spacing and jacking force are studied and analyzed(the numerical calculation model is established by MIDAS-GTS),and the following research results are obtained.(1)Pipe diameter of pipe jacking:comprehensive analysis shall be carried out according to the construction geological conditions,equipment requirements,structural section,surrounding environmental conditions and project cost,and it shall be minimized on the premise of meeting the requirements of construction space(generally not less than 2 m)and structural size.(2)Pipe jacking wall thickness:it shall be comprehensively determined according to the jacking and cutting construction sequence,geological conditions and finite element numerical simulation results(generally,it is not more than 1%of pipe diameter).(3)Pipe jacking spacing:the maximum pipe jacking spacing shall be calculated according to the soil arching effect theory,and the pipe jacking spacing shall be reasonably determined in combination with the construction space requirements.(4)pipe jacking force:it can be calculated according to the construction process and the principle that the external friction of pipe jacking is the jacking force.
作者
陈五二
Chen Wuer(China Railway Engineering Design and Consulting Group Co.,Ltd.,BeiJing 100055,China)
出处
《铁道勘察》
2019年第6期50-55,共6页
Railway Investigation and Surveying
关键词
超前模筑衬砌
顶管
关键参数
地铁隧道
Advance form lining
Pipe jacking
Key parameters
Metro tunnel
