摘要
为更加正确、合理地评价坑中坑开挖对基坑围护结构变形特性的影响,依托某实际工程,采用可以考虑土体硬化特征的HMC本构模型模拟地基土,建立了可以考虑坑中坑影响的内撑支护基坑的数值模型,引入外坑围护结构最大侧移增长率ξ,通过主要参数敏感性分析(坑距比α、内外坑深度比χ及内外坑围护结构插入比λin、λout),揭示了坑中坑式基坑开挖变形特性,诠释了内外坑相互作用机理。计算结果表明,坑距比α与内外坑深度比χ是影响基坑围护结构变形特性的最主要因素,ξ随着α的增加逐渐降低至趋于稳定,而随着χ的增加,ξ则逐渐增大。增大λout及λin将显著降低内、外坑围护结构的侧移值;但均对ξ影响不明显。
In order to evaluate the influence of the pit-in-pit excavations on the deformation characteristics of supporting structures more accurately and rationally,the HMC constitutive model which can consider the hardening characteristics of soil was adopted to simulate the foundation soil,then a numerical model of the braced excavation considering the influence of the inner pit excavation was established. The growth percentage ξ of maximum lateral displacement of supporting structure of outer pit was adopted. Through the sensitivity analysis of main influencing parameters( i. e.,the ratio α of the distance between the inner and outer pit,the depth ratio χ and the insertion ratio λin and λoutof the inner and outer supporting structures),the deformation characteristics of pit-in-pit braced excavations are revealed,and the interaction mechanism is explained. The results showed that the ratio α and χ are the most significant factors affecting the deformation characteristics of the supporting structures. With the increase of α,ξ gradually decreases to tend to be stable,but increases with the increase of χ. The lateral displacement value of the supporting structures of the inner and outer pit would be significantly increased when the value of λinand λoutincrease,but the influence may not be obvious.
作者
陈秋旺
CHEN Qiuwang(Fujian West Coast Architecture Design Institute,Fuzhou 350011)
出处
《福建建筑》
2018年第12期38-43,共6页
Fujian Architecture & Construction
关键词
坑中坑
内撑支护
围护结构
变形特性
敏感性分析
Pit in pit
Internal brace
Supporting structure
Deformation characteristics
Sensitivity analysis
