摘要
以成都轨道交通11号线新川路至龙灯山盾构区间下穿沙河沟桥工程为例,通过方案比选,选择拆桥重建作为穿越方案,破除盾构穿越范围内桥梁桩基;盾构穿越河流段,覆土为1.89 m.为满足盾构抗浮,隧道两侧设置长12 m、间距4m的抗拔桩,顶部设800 mm厚抗浮板.针对工程雨季施工以及结合盾构工筹,改变原有施工顺序:抗拔桩施工完成后,先填土(盾构顶部覆土6m),保障盾构穿越.盾构穿越时,做好同步注浆以及二次注浆;盾构区间贯通之后,通过管片背后注浆,对管片上半环2 m范围、下半环1 m范围进行加固.隧道内采用满载电瓶车+两侧压沙袋的方法进行抗浮压载、分块分层挖土(分层厚度不大于1 m)、先施工桥梁承台然后再施工抗浮板的应对措施.
The paper took the Shahegou Bridge project from the Xinchuan Road to the Longdengshan shield section of Chengdu Rail Transit Line 11 as an example,through the comparison of the schemes,the bridge reconstruction was selected as the traversing scheme to break the bridge pile foundation in the shield crossing range.The shield crossed the river section with the soil cover of 1.89 m.In order to meet the requirement of shield anti-floating.uplift piles with a length of 12 m and a distance of 4 m were installed on both sides of the tunnel,and 800 mm thick anti-floating slab was installed on the top of the tunnel.In view of the construction of the rainy season in the project and the construction of the shield,the original construction sequence was changed.After the construction of pull-out piles was completed,the earth Was filled first and the top of the shield Was covered for 6 m to ensure the shield.While the shield passing,synchronous grouting and secondary grouting should be done well as well as secondary grouting.After the shield section was penetrated,the back of the segment was grouted,the upper half of the segment was 2 m,and the lower half of the segment was reinforced.The tunnel Was filled with a sandbag on both sides to carry out anti-floating and ballasting with a full-loaded battery.The layered soil was excavated in sections,and the layer thickness was less than 1 m.First,the bridge cap was constructed,and then the anti-floating slab Was constructed.
作者
姚文峰
Yao Wenfeng(China Railway Fifth Survey and Design Institute Group Co.Ltd.,Beijing 102600,China)
出处
《铁道建筑技术》
2019年第S02期164-167,共4页
Railway Construction Technology
关键词
下穿
河流及桥梁
施工工艺
监控量测
underneath crossing
rive and bridge
construction technique
monitoring and measurement
