2016年12月上第45卷第23期
DOI:10.7672/sgjs2016230001
施工技术
CONSTRUCTION TECHNOLOGY
超深基坑内坑中坑二次支护工程桩与混凝土
悬臂桩交叉作用施工技术
陈浩，黄爽，潘春龙
（中建三局集团有限公司东北分公司，辽宁沈阳110000）
[摘要】沈阳宝能环球金融中心项目T1塔楼为在建东北第一高楼，底板由四周到中间厚度分别为2.5,4.2,6.0， 7.6，8.4，11.1m，电梯基坑处底板最深达11.1m，板项标高为=24.650m，基底标高为=30.650m，局部最深电梯井坑底板底面标高为-35.750m。而电梯基坑开挖深度与周边开挖深度相差5.1m，为超深基坑内的深坑中坑，为了土方在开挖过程中坑中坑支护安全稳定性得到保证，本工程在土方开挖过程中采用工程桩和混凝土悬臂桩结合形成排桩支护体系对坑中坑进行支护，而且采用素混凝土承台模替代传统砖胎模，既保证了坑中坑开挖及施工安全，且加快了施工进度
【关键词］高层建筑；基坑；支护；大底板；工程桩；混凝土悬臂桩；施工技术
［中图分类号］TU753
【文献标识码］A
[文章编号］1002-8498(2016)23-0001-03
ConcreteCantileverPilesforthePit-in-pitSecondarySupportin
Ultra-deepFoundationExcavation ChenHao，HuangShuang,PanChunlong
( Northeast Branch of China Construction Third Engineering Group Co. ,Lid. ,
Shenyang,Liaoning110000,China)
Abstract : The Tower 1 of Shenyang Baoneng Global Financial Center which is in construction will be the tallest building in the northeast of China. The thickness of base plate varies from the perimeter to the middle, which is 2.5m, 4.2m, 6.Om, 7.6m, 8. 4m with the maximum depth of elevator pit 11.1m The surface elevation of the plate is-24.650m,and the bottom elevation is-30.650m.The surface elevation of the deepest elevator shaft foundation excavation is 35. 75Om. The excavation depth of the elevator shaft is 5. 1m which is deep pit-in-pit in ultra-deep foundation excavation. To make the safety and stability of pit-in-pit support guaranteed in soil excavation, the project applies engineering pile and soaoaoaeo structure.And plain concrete formwork of cushion cap is utilized instead of traditional brick form,which not only ensures the safety of the excavation but also accelerates the construction progress.
Key words: tall buildings; foundation excavation; supports; massive base plate; engineering piles; concrete cantilever piles; construction
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引言
随着我国城市高层建筑的兴起、地下空间的迅
速开发，基坑在开挖深度、开挖数量、开挖平面尺寸及使用领域方面都得到高速发展，深大基坑已非常
【作者简介］陈浩，总经理，党委书记，高级工程师，E-mail： ec3ch@ 163. cc
【收稿日期]方劳数据
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常见，而且在深基坑中仍会出现坑中坑，这样坑中坑开挖及其支护就会严重受到场地条件等制约，简单的放坡开挖支护等已无法满足要求，这样促使坑中坑支护需要考虑使用先进的施工技术以达到支护目的。为了保证基坑在开挖过程中及后期施工过程的安全性，本工程采用混凝土悬臂桩和工程桩交叉结合的方式使之形成排桩支护体系对坑中坑