岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2013年
3期
520-527
,共8页
基坑工程%围护墙变形%实测%混凝土收缩%混凝土垫层%超长混凝土结构
基坑工程%圍護牆變形%實測%混凝土收縮%混凝土墊層%超長混凝土結構
기갱공정%위호장변형%실측%혼응토수축%혼응토점층%초장혼응토결구
foundation pit engineering%deformation of retaining wall%field measurement%concrete shrinkage%concrete cushion%overlong concrete structure
基于实测数据,对上海中心大厦裙房逆作超大深基坑工程的围护墙变形规律进行分析.分析结果表明,在垫层混凝土浇筑完成至梁板结构混凝土浇筑完成期间,围护墙侧移增量很小,垫层对围护墙变形具有明显的约束效应;在此期间,因作为垫层支撑点的圆形地墙受偏载作用引起较大的变形,导致测点P04墙体侧移增量较大;结合现场施工条件,对混凝土垫层约束效应的发挥进行说明.在混凝土结构养护期间,超长水平支撑梁板结构或大底板的混凝土收缩,引起围护墙侧移增量较大;且在大底板混凝土养护期间,西侧测点P23的围护墙侧移增量大于最后一次土方开挖所引起的墙体侧移增量;而短跨水平梁板结构混凝土收缩对围护墙变形影响可忽略.结合上述规律,给出相应的施工措施,以便减小基坑变形.
基于實測數據,對上海中心大廈裙房逆作超大深基坑工程的圍護牆變形規律進行分析.分析結果錶明,在墊層混凝土澆築完成至樑闆結構混凝土澆築完成期間,圍護牆側移增量很小,墊層對圍護牆變形具有明顯的約束效應;在此期間,因作為墊層支撐點的圓形地牆受偏載作用引起較大的變形,導緻測點P04牆體側移增量較大;結閤現場施工條件,對混凝土墊層約束效應的髮揮進行說明.在混凝土結構養護期間,超長水平支撐樑闆結構或大底闆的混凝土收縮,引起圍護牆側移增量較大;且在大底闆混凝土養護期間,西側測點P23的圍護牆側移增量大于最後一次土方開挖所引起的牆體側移增量;而短跨水平樑闆結構混凝土收縮對圍護牆變形影響可忽略.結閤上述規律,給齣相應的施工措施,以便減小基坑變形.
기우실측수거,대상해중심대하군방역작초대심기갱공정적위호장변형규률진행분석.분석결과표명,재점층혼응토요축완성지량판결구혼응토요축완성기간,위호장측이증량흔소,점층대위호장변형구유명현적약속효응;재차기간,인작위점층지탱점적원형지장수편재작용인기교대적변형,도치측점P04장체측이증량교대;결합현장시공조건,대혼응토점층약속효응적발휘진행설명.재혼응토결구양호기간,초장수평지탱량판결구혹대저판적혼응토수축,인기위호장측이증량교대;차재대저판혼응토양호기간,서측측점P23적위호장측이증량대우최후일차토방개알소인기적장체측이증량;이단과수평량판결구혼응토수축대위호장변형영향가홀략.결합상술규률,급출상응적시공조시,이편감소기갱변형.
@@@@Based on field measured data,the lateral deformation laws of retaining wall,which belongs to super-large deep foundation pit of Shanghai Tower podium,are analyzed. The analytical results show that,during the period from completion of cushion concrete placement to the completion of beam-slab concrete placement,the increment in lateral deformation of retaining wall is very small,indicating that the constraint effect of cushion on deformation of retaining wall is significant. However,due to the eccentric load effect,the lateral deformation of circle wall,which is the support point of cushion,is relatively large;and it leads to a large increment in lateral deformation of measuring point P04 during this period. Combining with the site construction conditions,the constraint effect of cushion concrete is explained. During the period of structure concrete curing,due to the concrete shrinkage of overlong beam-slab structure or bottom plate,the increment in lateral displacement of retaining wall is large. During the curing period of bottom plate,the increment in lateral deformation of measuring point P23 is larger than that caused by soil excavation for the last time. For the short concrete structure,the effect of concrete shrinkage on the lateral displacement of retaining wall can be neglected. Finally,based on the above laws,some suggestions are proposed to control the deformation of retaining wall effectively.
