铁道科学与工程学报
鐵道科學與工程學報
철도과학여공정학보
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
2010年
1期
52-58
,共7页
雷明锋%彭立敏%施成华%翟旭东
雷明鋒%彭立敏%施成華%翟旭東
뢰명봉%팽립민%시성화%적욱동
长大深基坑%围岩变形%空间有限元%动态模拟
長大深基坑%圍巖變形%空間有限元%動態模擬
장대심기갱%위암변형%공간유한원%동태모의
large-long-deep foundation pit%surrounding rock deformation%spatial FEM%dynamic simulation
针对目前对深基坑施工围岩动态变形规律缺乏系统研究的现状,以武广客运专线上的金沙洲隧道明挖段深基坑工程为实例,建立空间有限元模型,实现了施工动态模拟;分析了长大深基坑施工过程中,各部位围岩的动态变形和分布规律,并指出了围岩变形的关键位置与施工环节.研究结果表明:坑周土体沉降在竖直方向表现为沿深度逐步减小,最大值出现在地表,但在水平方向上,沉降规律较复杂,受到围护桩自身刚度的影响,呈现为"勺"形,最大沉降位置并非出现在桩顶位置,而是离桩项约11 m处;坑周土体水平位移随基坑开挖逐渐增大,且位移中心逐渐下移,直至开挖深度2/3处;基坑开挖后,基底产生一定程度的回弹和内挤变形.开挖深度越大.土体条件越差,变形越大.
針對目前對深基坑施工圍巖動態變形規律缺乏繫統研究的現狀,以武廣客運專線上的金沙洲隧道明挖段深基坑工程為實例,建立空間有限元模型,實現瞭施工動態模擬;分析瞭長大深基坑施工過程中,各部位圍巖的動態變形和分佈規律,併指齣瞭圍巖變形的關鍵位置與施工環節.研究結果錶明:坑週土體沉降在豎直方嚮錶現為沿深度逐步減小,最大值齣現在地錶,但在水平方嚮上,沉降規律較複雜,受到圍護樁自身剛度的影響,呈現為"勺"形,最大沉降位置併非齣現在樁頂位置,而是離樁項約11 m處;坑週土體水平位移隨基坑開挖逐漸增大,且位移中心逐漸下移,直至開挖深度2/3處;基坑開挖後,基底產生一定程度的迴彈和內擠變形.開挖深度越大.土體條件越差,變形越大.
침대목전대심기갱시공위암동태변형규률결핍계통연구적현상,이무엄객운전선상적금사주수도명알단심기갱공정위실례,건립공간유한원모형,실현료시공동태모의;분석료장대심기갱시공과정중,각부위위암적동태변형화분포규률,병지출료위암변형적관건위치여시공배절.연구결과표명:갱주토체침강재수직방향표현위연심도축보감소,최대치출현재지표,단재수평방향상,침강규률교복잡,수도위호장자신강도적영향,정현위"작"형,최대침강위치병비출현재장정위치,이시리장항약11 m처;갱주토체수평위이수기갱개알축점증대,차위이중심축점하이,직지개알심도2/3처;기갱개알후,기저산생일정정도적회탄화내제변형.개알심도월대.토체조건월차,변형월대.
According to the present situation that there is lack of a system research about the dynamic change law of surrounding rock in deep foundation pit construction,Jinshazhou tunnel open cut works on Wuguang passenger dedicated hne was taken as an engineering example,a spatial FEM model was established,which implemented the construction dynamic simulation,and an overall analysis about the dynamic deformation law and distribution of surrounding rock was made.The results show that the settlement of soil around deep foundation pit decreases gradually along the depth and the maximum value appears in ground surface,but on horizontal direction,the subsidence rule is more complex influenced by the retaining pile own rigidity,the settlement curve represented as "spoon-like"and the biggest subsidence position appears by no means in the head of piles,but leaves the head of pile approximately 11 m.The horizontal displacement of soil around deep foundation pit increases gradually with excavation,and the displacement center moves gradually until cutting depth 2/3.The basement will generate uplift and in-push in some degree after the inner soil is excavated,and the cutting depth is bigger,the soil condition is worse,and the deformation is bigger.