【摘要】：隨著城市化建設(shè)進(jìn)程節(jié)奏的逐步加快,城市里面人口越來越多,地面空間變得越來越擁擠,地下建筑的大規(guī)模建設(shè)解決了這個問題。在地鐵施工過程中,由于地下土體被挖出,造成洞室周圍土體應(yīng)力重分部,不可避免的產(chǎn)生地表沉降。因此,對地下建筑施工引發(fā)的地表沉降規(guī)律進(jìn)行研究十分重要。本文首先對地鐵建設(shè)引發(fā)的地表沉降的研究成果進(jìn)行了總結(jié),并對淺埋暗挖法以及監(jiān)控測量技術(shù)進(jìn)行了概括性的描述,并結(jié)合北京地鐵九龍山站7號線地鐵站及14號線地鐵站車站主體84個監(jiān)測斷面,附屬結(jié)構(gòu)60個監(jiān)測斷面,區(qū)間20個監(jiān)測斷面,共計164個斷面,并剔除之中9個數(shù)據(jù)異常的監(jiān)測斷面,最終選取155個斷面的現(xiàn)場實際監(jiān)控測量數(shù)據(jù)進(jìn)行分析,并輔以FLAC3D數(shù)值模擬。通過研究所得,對九龍山站PBA工法施工的車站主體進(jìn)行了小導(dǎo)洞開挖方法的優(yōu)化,本文主要結(jié)論如下:1.區(qū)間隧道采用臺階法施工,開挖上臺階的施工,對地表沉降影響較大,占總沉降量的50%-65%,因此縮短開挖的進(jìn)尺,及時使得施工掌子面封閉成環(huán)可有效減緩地表沉降;2.隧道上覆建筑的存在,由于建筑的自重作用對隧道拱部土體產(chǎn)生壓應(yīng)力,改變了土體中應(yīng)力的分布,因此地表受到的影響很大,引起了較大的沉降量,并且使得沉降槽平緩,寬度變大;3.施工方法及隧道斷面形狀對沉降槽寬度系數(shù)影響較大,上覆埋深基本相同的情況下,不同施工方法產(chǎn)生沉降槽寬度由大到小的排列順序為PBA工法中洞法CRD工法;4.高跨比的增加使得沉降槽寬度變小,沉降曲線寬度參數(shù)也相應(yīng)變小,地層損失率也有所減小,在粉質(zhì)粘土和粉細(xì)砂為主的條件下,成拱效應(yīng)高跨比的值在1.2-1.5之間;5.PBA工法步驟較多,小導(dǎo)洞施工階段,采用“先上后下,交錯施工”的施工方案對地層的影響較小,引發(fā)沉降量較小,通過現(xiàn)場監(jiān)控測量數(shù)據(jù)與數(shù)值模擬計算結(jié)果比較分析,可知計算結(jié)果較為合理,可為今后的設(shè)計和施工提供參考;
[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，

本文編號：2474443