摘要
掌握黄土地层地铁车站洞桩法施工竖向土压力的分布规律对于该地层车站的设计和施工至关重要。以西安地铁某车站为工程背景,基于数值模拟,分析洞桩法施工过程中竖向土压力的变化规律,以及导洞的不同施工顺序对竖向土压力分布的影响,并与现场实测数据进行对比分析,结果表明:(1)上层边导洞拱脚处竖向土压力约为拱顶处竖向土压力的1.26倍,中间导洞拱脚处竖向土压力约为拱顶处竖向土压力的1.16倍,表明中间导洞B、C拱顶受力更为均匀。(2)相较于同层导洞开挖顺序,上下层导洞开挖顺序对导洞竖向土压力影响更大,“先上后下,现边后中”的导洞开挖顺序更为合理。(3)扣拱施工时,最大的竖向压力发生在扣拱和冠梁、顶纵梁交接处,并且拱脚处的竖向压力要远高于拱顶,表明拱-桩-柱体系能有效承担结构顶部受力。
It is very important for the design and construction of subway stations in loess stratum to master the distribution law of vertical earth pressure in hole-pile construction.Taking a subway station in Xi'an as the engineering background,based on numerical simulation,the variation law of vertical earth pressure in the construction process of cave-pile method and the influence of different construction sequences of guide tunnels on vertical earth pressure distribution were analyzed,and compared with the field measured data,the results showed that:(1)The vertical earth pressure at the arch foot of the upper side guide hole is about 1.26 times of the vertical earth pressure at the top of the arch,and the vertical earth pressure at the arch foot of the middle guide hole is about 1.16 times of the vertical earth pressure at the top of the arch,indicating that the force of the middle guide hole B and C arches is more uniform.(2)Compared with the excavation sequence of the same layer guide tunnel,the excavation sequence of the upper and lower guide tunnels has a greater influence on the vertical soil pressure of the guide tunnel.The excavation sequence of the guide tunnels with"first up and then down,and the current edge and then middle"is more reasonable.(3)During the construction of buckle arch,the maximum vertical pressure occurs at the junction of buckle arch,crown beam and top longitudinal beam,and the vertical pressure at the arch foot is much higher than that at the arch top,indicating that the arch-pile-column system can effectively bear the load on the top of the structure.
作者
薛瑞蕾
XUE Ruilei(Xi'an Traffic Engineering Institute,Xi'an Shaanxi 710300,China)
出处
《西安交通工程学院学术研究》
2024年第1期5-11,共7页
Academic Research of Xi'an Traffic Engineering Institute
关键词
洞桩法
黄土
竖向土压力
导洞开挖顺序
PBA method
loess
vertical earth pressure
excavation sequence
