TRD技术在超大基坑中的应用
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摘要
武汉市长江航运中心属超大面积深基坑工程,地质勘查发现,对基坑开挖影响最大的软~流塑、高压缩性、强度较低的粉质粘土夹粉土在整个场地均有分布,因紧邻长江,基坑工程还将面临极为严峻的承压水影响问题。基于地质水文条件,地下二层区域采用常规的钻孔灌注桩结合三轴水泥土搅拌桩止水帷幕作为支护体。对于地下三层区域,其受承压水影响严重,止水帷幕深度较大。TRD工法地下连续墙可施工的深度较大,而且地层适应性也广,可满足本工程隔断地下水的要求,因此,地下三层区域选择地下连续墙(TRD工法)支护体。Ⅰ区和Ⅱ区的水平支撑均采用对撑结合边桁架支撑。
The Yangtze River Navigation Administration Center Project is located at the intersection of Yuanjiang Boulevard and Minsheng Road in Jiangan District.The proposed building has a total area of 46,000m2 with a building area of 31,500m2.The foundation excavation area is 38,600m2,with a perimeter f 888 meters.The proposed excavation depth varies from 10.7to21.9meters and this type of deep excavation can be classified as super-large excavation project.Based on the hydrological and geological conditions at site,the conventional cast-in-place reinforced concrete pile with three-axis cement mixing curtain as a seepage cut-off wall was used as supporting system in areas with two-story underground spaces.In areas with three-story underground spaces,the hydraulic pressure is high due to the required excavation depth.The slurry walls formed by the Trench Cutting Remixing Deep Wall(TRD method was used.The TRD walls can have a large structural depth and is applicable in a wide variety of subsurface conditions.The cross strut supports with corner supports using truss system in the horizontal direction are used in both areas.
The Yangtze River Navigation Administration Center Project is located at the intersection of Yuanjiang Boulevard and Minsheng Road in Jiangan District.The proposed building has a total area of 46,000m2 with a building area of 31,500m2.The foundation excavation area is 38,600m2,with a perimeter f 888 meters.The proposed excavation depth varies from 10.7to21.9meters and this type of deep excavation can be classified as super-large excavation project.Based on the hydrological and geological conditions at site,the conventional cast-in-place reinforced concrete pile with three-axis cement mixing curtain as a seepage cut-off wall was used as supporting system in areas with two-story underground spaces.In areas with three-story underground spaces,the hydraulic pressure is high due to the required excavation depth.The slurry walls formed by the Trench Cutting Remixing Deep Wall(TRD method was used.The TRD walls can have a large structural depth and is applicable in a wide variety of subsurface conditions.The cross strut supports with corner supports using truss system in the horizontal direction are used in both areas.
引文
[1]岩土工程勘察规范(GB50021-2001)[S].
[2]混凝土结构设计规范(GB50010-2002)[S].
[3]钢结构设计规范(GB50017-2003)[S].
[4]安关峰,宋二祥,高俊岳.广州地铁小谷围站基坑支护设计与检测分析[J].岩土力学,2006,27(2):317-322.
[5]曾进群,杨光华,蔡晓英,等.复杂环境下多种支护型式共用的基坑设计实例[J].岩土工程学报,2006,28(z1):1573-1576.
[2]混凝土结构设计规范(GB50010-2002)[S].
[3]钢结构设计规范(GB50017-2003)[S].
[4]安关峰,宋二祥,高俊岳.广州地铁小谷围站基坑支护设计与检测分析[J].岩土力学,2006,27(2):317-322.
[5]曾进群,杨光华,蔡晓英,等.复杂环境下多种支护型式共用的基坑设计实例[J].岩土工程学报,2006,28(z1):1573-1576.