复杂环境下某深厚软土基坑的实测性状研究

应宏伟; 孙威; 吕蒙军; 陈东

doi:10.11779/CJGE2014S2074

复杂环境下某深厚软土基坑的实测性状研究 English Version

应宏伟^{1, 2},
孙威^{1, 2},
吕蒙军³,
陈东⁴

1. 浙江大学滨海和城市岩土工程研究中心,浙江杭州 310058;
2. 浙江大学软弱土与环境土工教育部重点实验室,浙江杭州 310058;
3. 杭州运河集团投资发展有限公司,浙江杭州 310014;
4. 浙江省建筑设计研究院,浙江杭州 310006

基金项目: 国家自然科学基金项目（51278462）; 浙江省建设厅科技推广应用研究项目

详细信息

作者简介:
应宏伟(1971- ),男,副教授,主要从事岩土工程的教学和科研工作。E-mail: ice898@zju.edu.cn。

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出版历程
- 收稿日期: 2014-07-27
- 发布日期: 2014-07-27

Measured characteristics of a deep soft soil excavation in complex environment

YING Hong-wei^{1, 2},
SUN Wei^{1, 2},
LÜ Meng-jun³,
CHEN Dong⁴

1. Research Center of Coastal and Urban Geotechnical Engineering, Zhejiang University, Hangzhou 310058,China;
2. MOE, Key Laboratory of Soft Soils and Geoenvironmental Engineering of Ministry of Education, Zhejiang University, Hangzhou 310058, China;
3. The Hangzhou canal group investment and Development Co., Ltd., Hangzhou 310014, China;
4. Zhejiang Province Institute of Architectural Design and Research, Hangzhou 310006, China

摘要

摘要: 详尽分析了杭州某上部带有较厚硬壳层的深厚软黏土地基中,开挖深度为17.4~19.8 m,采用地下连续墙和多层钢筋混凝土支撑作为支护结构的超深基坑工程的实测性状。现场监测内容包括基坑侧壁土体水平位移、坑外地表沉降及内支撑轴力。研究表明,本案例基坑的最大水平位移与基坑最大开挖深度之比介于0.24%~0.75%,最大水平位移超过100 mm,其中蠕变变形占总侧向变形的比例高达44%~56%,基坑水平位移蠕变速率为0.15~0.76 mm/d,蠕变速率与基坑开挖深度和基底附近土层性质有密切关系;“T”型地下连续墙和隔断墙技术对减小侧壁土体变形有一定作用。基坑坑外横向地面沉降大致呈抛物线分布,坑外纵向沉降大致呈马鞍形,地表周围土体最大沉降与基坑最大开挖深度之比介于0.26%~0.7%,最大沉降量与坑壁最大侧向位移量的关系大致为~,沉降蠕变速率为0.1~0.6 mm/d。随着开挖及相邻支撑的浇筑及拆除,多层支撑支护结构中各层支撑的轴力不断变化。
- 深基坑 /
- 水平位移 /
- 沉降 /
- 蠕变速率 /
- 支撑轴力
Abstract: The monitoring data of a 17.4 m~19.8 m-deep multi-strutted soft clay excavation built on hard shell layer soft soil foundation in Hangzhou is analyzed. The deep excavation is supported by a concrete diaphragm wall and multi-storey reinforced concrete brace. The monitoring includes soil and wall deflections, surface and subsurface ground settlements, axial forces of concrete struts. This study shows that the maximum horizontal displacements are 0.24%H_m~0.75%H_m, in which H_m is the total excavation depth. The maximum horizontal displacement is larger than 100 mm, in which the proportions of creep deformation reach up to 44%~56%. The horizontal creep rates are in 0.15~0.76 mm/d and closely related with the excavation depth and the properties of the soils near the base. The technology of T-diaphragm wall and partition wall can reduce the horizontal displacement of the excavation to some extent. The distribution of the lateral settlement is in a parabolic shape and the longitudinal settlement is in a saddle shape. The maximum settlements are 0.26%H_m ~0.7%H_m and the settlement rates are 0.1~0.6 mm/d. The relationship between the maximum settlements is between and 2.57, in which is the maximum horizontal displacement. The axial forces of the struts change dynamically during the excavation and construction or removal of the adjacent braces.
- deep excavation /
- horizontal deflection /
- settlement /
- creep rate /
- strut force

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参考文献(11)

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