暗挖导洞不同开挖施工顺序对地表沉降的影响规律研究  

Research on the Influence Law of Different Excavation Construction Sequences of Undercutting Pilot Tunnel on Surface Settlement

作　　者：任亨 REN Heng(China Railway Electrification Engineering Group Co.,Ltd.,Beijing 100071,China)

机构地区：[1]中铁电气化局集团有限公司,北京100071

出　　处：《工程技术研究》2024年第22期218-220,共3页Engineering and Technological Research

摘　　要：文章以某地铁车站为例,采用数值模拟法分析了“先下后上”和“先上后下”两种施工顺序下,PBA-8导洞暗挖全过程对车站主体地表沉降的影响规律。研究结果表明,“先下后上”和“先上后下”两种施工顺序对车站主体地表位移变形影响规律基本相同,最大沉降分别为30 mm及23 mm,均小于控制值60 mm。“先下后上”PBA暗挖的主要影响区域为地下车站外轮廓10 m内地层,而“先上后下”PBA暗挖的主要影响区域为地下车站外轮廓5 m内地层。可见,“先上后下”对地表沉降的影响范围以及沉降值均较小,PBA施作关键施工步序对地表产生的位移影响不受上下导洞开挖顺序的影响。Taking a subway station as an example,this paper analyzes the infl uence law of the whole undercutting process of PBA-8 pilot tunnel on the surface settlement of the main body of the station under two construction sequences of"fi rst down and then up"and"fi rst up and then down"by numerical simulation method.The results show that the influence law of the two construction sequences of"fi rst down and then up"and"fi rst up and then down"on the surface displacement and deformation of the main body of the station is basically the same.The maximum settlement is 30 mm and 23 mm respectively,which is less than the control value of 60 mm.The main infl uence area of"fi rst down and then up"PBA undercutting is the stratum within 10 m of the outer contour of the underground station,while the main infl uence area of"fi rst up and then down"PBA undercutting is the stratum within 5 m of the outer contour of the underground station.It can be seen that the influence range and settlement value of"first up and then down"on the surface settlement are small,and the infl uence of the key construction sequence of PBA on the displacement of the surface is not affected by the excavation sequence of the upper and lower pilot tunnels.

关 键 词：洞桩法 PBA-8导洞 数值模拟 施工顺序 地表沉降 沉降槽 

分 类 号：U231.3[交通运输工程—道路与铁道工程] P642.26[天文地球—工程地质学]