北京地铁浅埋暗挖法施工引起地表沉降规律研究
发布时间：2019-05-11 11:05
【摘要】：随着城市化建设进程节奏的逐步加快,城市里面人口越来越多,地面空间变得越来越拥挤,地下建筑的大规模建设解决了这个问题。在地铁施工过程中,由于地下土体被挖出,造成洞室周围土体应力重分部,不可避免的产生地表沉降。因此,对地下建筑施工引发的地表沉降规律进行研究十分重要。本文首先对地铁建设引发的地表沉降的研究成果进行了总结,并对浅埋暗挖法以及监控测量技术进行了概括性的描述,并结合北京地铁九龙山站7号线地铁站及14号线地铁站车站主体84个监测断面,附属结构60个监测断面,区间20个监测断面,共计164个断面,并剔除之中9个数据异常的监测断面,最终选取155个断面的现场实际监控测量数据进行分析,并辅以FLAC3D数值模拟。通过研究所得,对九龙山站PBA工法施工的车站主体进行了小导洞开挖方法的优化,本文主要结论如下:1.区间隧道采用台阶法施工,开挖上台阶的施工,对地表沉降影响较大,占总沉降量的50%-65%,因此缩短开挖的进尺,及时使得施工掌子面封闭成环可有效减缓地表沉降;2.隧道上覆建筑的存在,由于建筑的自重作用对隧道拱部土体产生压应力,改变了土体中应力的分布,因此地表受到的影响很大,引起了较大的沉降量,并且使得沉降槽平缓,宽度变大;3.施工方法及隧道断面形状对沉降槽宽度系数影响较大,上覆埋深基本相同的情况下,不同施工方法产生沉降槽宽度由大到小的排列顺序为PBA工法中洞法CRD工法;4.高跨比的增加使得沉降槽宽度变小,沉降曲线宽度参数也相应变小,地层损失率也有所减小,在粉质粘土和粉细砂为主的条件下,成拱效应高跨比的值在1.2-1.5之间;5.PBA工法步骤较多,小导洞施工阶段,采用“先上后下,交错施工”的施工方案对地层的影响较小,引发沉降量较小,通过现场监控测量数据与数值模拟计算结果比较分析,可知计算结果较为合理,可为今后的设计和施工提供参考;
[Abstract]:With the gradual acceleration of the pace of urbanization construction, the population in the city is more and more, and the ground space is becoming more and more crowded. The large-scale construction of underground buildings has solved this problem. In the process of subway construction, because the underground soil is dug out, the stress of the soil around the caverns is divided, and the surface settlement is inevitable. Therefore, it is very important to study the law of surface subsidence caused by underground building construction. In this paper, the research results of surface subsidence caused by subway construction are summarized, and the shallow excavation method and monitoring and measurement technology are described in general. And combined with Beijing Metro Jiulongshan Station Line 7 subway station and line 14 subway station main 84 monitoring sections, subsidiary structure 60 monitoring sections, interval 20 monitoring sections, a total of 164 sections. Nine monitoring sections with abnormal data are eliminated, and the actual monitoring and measurement data of 155sections are selected for analysis, supplemented by FLAC3D numerical simulation. Through the research, the excavation method of the small guide tunnel is optimized for the main body of the station constructed by PBA construction method of Jiulong Mountain Station. The main conclusions of this paper are as follows: 1. The interval tunnel is constructed by step method, and the construction of excavating the upper step has a great influence on the surface settlement, accounting for 50% 鈮，
本文编号：2474443
[Abstract]:With the gradual acceleration of the pace of urbanization construction, the population in the city is more and more, and the ground space is becoming more and more crowded. The large-scale construction of underground buildings has solved this problem. In the process of subway construction, because the underground soil is dug out, the stress of the soil around the caverns is divided, and the surface settlement is inevitable. Therefore, it is very important to study the law of surface subsidence caused by underground building construction. In this paper, the research results of surface subsidence caused by subway construction are summarized, and the shallow excavation method and monitoring and measurement technology are described in general. And combined with Beijing Metro Jiulongshan Station Line 7 subway station and line 14 subway station main 84 monitoring sections, subsidiary structure 60 monitoring sections, interval 20 monitoring sections, a total of 164 sections. Nine monitoring sections with abnormal data are eliminated, and the actual monitoring and measurement data of 155sections are selected for analysis, supplemented by FLAC3D numerical simulation. Through the research, the excavation method of the small guide tunnel is optimized for the main body of the station constructed by PBA construction method of Jiulong Mountain Station. The main conclusions of this paper are as follows: 1. The interval tunnel is constructed by step method, and the construction of excavating the upper step has a great influence on the surface settlement, accounting for 50% 鈮，
本文编号：2474443
本文链接：https://www.wllwen.com/kejilunwen/diqiudizhi/2474443.html
