大断面顶管侧向开洞口型管片结构及其内力分析

Structure of Large Section Pipe-jacking Segment with Lateral Opening and Its Internal Force Analysis

目前大断面顶管管片一般采用整体式钢筋混凝土管片,纵向接头采用"承插式"接头,开大洞口型管片如果采用整体式钢筋混凝土管片,会由于该管片质量大、体积大而给该管片的吊装、运输和场地、纠偏等带来较大的麻烦,为了适应这种大断面顶管侧向开大洞口型管片结构需要,特设计一种侧向开大洞口型管片结构,这种管片结构由外环钢板、内环钢板、环肋板和纵肋板组成,而且这种管片在纵向上可以分成几段,分段和分段之间采用螺栓连接。本文以深圳某连接通道大断面顶管实际工程为例,分析了开大洞口型钢管片的各种工况组合情况,发现把洞口上方纵肋和洞口下方转角处纵肋构件加强后,整体应力都控制在安全合理的范围内。

Currently,large section pipe-jacking segment commonly adopts a monolithic reinforced concrete structure,using ＂socket and spigot joint＂as longitudinal joints. But if monolithic reinforced concrete applied to the large section pipe-jacking segment with lateral opening,it will cause problems at segments in the hoisting,transportation,site layout,rectification and so on due to its heavy weight and large volume. In order to accommodate the requirement of structure design,we specifically designed a large section pipe-jacking segment structure with lateral opening. This kind of pipe-jacking segment consists of outer and inner steel plates,hoop and longitudinal ribs,which can be divided into several sections in the longitudinal direction,with bolt connections between each other.This paper takes certain connecting tunnel using large section pipe jacking structure in Shenzhen as an example.Several load cases of steel sheet segment with lateral opening are analyzed. This study shows that,the overall stress can be reasonably controlled in a safe range after strengthening the longitudinal ribs both above the hole and at corners below the hole.