铁道标准设计
鐵道標準設計
철도표준설계
RAILWAY STANDARD DESIGN
2015年
6期
117-121,122
,共6页
小净距隧道%下穿%既有建筑物%桩基%衬砌受力
小淨距隧道%下穿%既有建築物%樁基%襯砌受力
소정거수도%하천%기유건축물%장기%츤체수력
Small clear distance tunnel%Underpassing%Existing building%Pile foundation%Stress of lining
近接施工引起的结构稳定性一直是城市地下工程关注的热点问题。以合肥小净距隧道穿越利海大厦办公楼工程实践为依托，建立三维数值力学模型，研究建筑物桩基变形特性、小净距隧道围岩塑性区分布和衬砌力学响应。研究结果表明：上台阶开挖引起桩基沉降占整个断面通过后总沉降量较大比例，上台阶施工过程控制尤为重要；接近隧道入口的桩基沉降量最大，从外向内逐渐减小；隧道通过20 m后，桩基沉降基本稳定。小净距隧道围岩塑性区主要集中在边墙、中隔墙和拱脚，建议设置中隔墙对拉锚杆和拱脚锁脚锚杆；先行洞洞周变形大于后行洞，先行洞隧道拱肩、中夹岩柱侧边墙二次衬砌安全系数最小，应作为施工阶段重点监测部位。研究成果对复杂环境城市地下工程设计、施工提供参考和借鉴。
近接施工引起的結構穩定性一直是城市地下工程關註的熱點問題。以閤肥小淨距隧道穿越利海大廈辦公樓工程實踐為依託，建立三維數值力學模型，研究建築物樁基變形特性、小淨距隧道圍巖塑性區分佈和襯砌力學響應。研究結果錶明：上檯階開挖引起樁基沉降佔整箇斷麵通過後總沉降量較大比例，上檯階施工過程控製尤為重要；接近隧道入口的樁基沉降量最大，從外嚮內逐漸減小；隧道通過20 m後，樁基沉降基本穩定。小淨距隧道圍巖塑性區主要集中在邊牆、中隔牆和拱腳，建議設置中隔牆對拉錨桿和拱腳鎖腳錨桿；先行洞洞週變形大于後行洞，先行洞隧道拱肩、中夾巖柱側邊牆二次襯砌安全繫數最小，應作為施工階段重點鑑測部位。研究成果對複雜環境城市地下工程設計、施工提供參攷和藉鑒。
근접시공인기적결구은정성일직시성시지하공정관주적열점문제。이합비소정거수도천월리해대하판공루공정실천위의탁，건립삼유수치역학모형，연구건축물장기변형특성、소정거수도위암소성구분포화츤체역학향응。연구결과표명：상태계개알인기장기침강점정개단면통과후총침강량교대비례，상태계시공과정공제우위중요；접근수도입구적장기침강량최대，종외향내축점감소；수도통과20 m후，장기침강기본은정。소정거수도위암소성구주요집중재변장、중격장화공각，건의설치중격장대랍묘간화공각쇄각묘간；선행동동주변형대우후행동，선행동수도공견、중협암주측변장이차츤체안전계수최소，응작위시공계단중점감측부위。연구성과대복잡배경성시지하공정설계、시공제공삼고화차감。
The stability of approaching construction has been a focus in the field of urban underground engineering. Based on a small clear distance tunnel underpassing office building of Lihai mansion in Hefei, three-dimensional numerical model is established to investigate deformation characteristics of building pile foundation, distribution of surrounding rock plastic zone of small clear distance tunnel, and mechanical response of lining. The results show that most of the settlement of pile foundation takes place during upper bench excavation and the control of upper bench excavation is of special importance. The settlement of pile foundation at the entry of tunnel dominates and decreases from extroversion to introversion. When the working face of tunnel advances 20 m the settlement of pile foundation tends to be stable. As the plastic zone of small clear distance tunnel concentrates at side-wall, mid-partition wall and arch-footing, it is suggested that tensile-type bolts should be installed at mid-partition wall and locking anchor adopted at arch-footing. The deformation of first-excavation hole is more than that of subsequent hole. The safety factors of lining at spandrel and side wall close to mid-partition wall are the minimum, where special monitoring should be addressed. The research results can supply to the design and construction of urban underground engineering in complicated environment.
