坑中坑型式非对称基坑围护体系力学特性研究
发布时间：2019-02-13 12:37
【摘要】：研究目的:坑中坑是工程中应用较为普遍的一种非对称基坑型式,目前相关的理论研究较少,工程设计中往往凭经验确定其影响范围。本文结合南京青奥轴线地下工程上部悬臂、下部设置内支撑的基坑工程,通过有限元计算分析,探讨坑中坑型式非对称基坑围护结构的变形和土压力分布特征,旨在为工程设计提供参考。研究结论:(1)内、外坑围护距离以及内坑开挖深度对坑中坑围护结构变形和受力影响显著;(2)随着内、外坑围护距离的不断缩小,内坑围护向坑外的变形不断减小直至偏向坑内,内坑围护外侧土压力可按外坑为地表计算且考虑一定的安全系数;(3)随着内坑开挖深度加大,内坑围护偏向基坑外侧位移加大;内坑未开挖或开挖较浅时,坑底以上外坑围护结构侧向土压力介于主动土压力和静止土压力之间;内坑开挖较深时,坑底以上土压力接近主动土压力,直至坑底逐步接近静止土压力;(4)本研究结果对类似基坑工程的分析与计算具有参考价值。
[Abstract]:Research purpose: the pit in the pit is a kind of asymmetric foundation pit which is widely used in engineering. At present, there are few related theoretical studies, and the influence range is often determined by experience in engineering design. In this paper, the deformation and earth pressure distribution characteristics of the pit type asymmetric foundation pit enclosure are discussed through finite element calculation and analysis, combined with the upper cantilever of the underground engineering of the Qingao axis in Nanjing and the foundation pit with inner support in the lower part. The aim is to provide reference for engineering design. The conclusions are as follows: (1) the distance of outer pit enclosure and the depth of pit excavation have significant effects on the deformation and force of the pit enclosure structure; (2) with the decrease of the distance between the outer pit and the inner pit, the deformation of the inner pit outside the pit decreases until it deviates to the pit. The external earth pressure of the inner pit enclosure can be calculated according to the outer pit surface and the safety factor can be considered to a certain extent. (3) with the increase of the excavation depth of the inner pit, the lateral displacement of the inner pit enclosure tends to increase, while the lateral earth pressure of the outer pit enclosure structure above the bottom of the pit is between the active earth pressure and the static earth pressure when the pit is not excavated or shallow; When the pit is deep, the earth pressure above the pit bottom is close to the active earth pressure until the bottom of the pit gradually approaches the static earth pressure. (4) the results of this study have reference value for the analysis and calculation of similar foundation pit engineering.
【作者单位】： 中铁第四勘察设计院集团有限公司;
【分类号】：TU753
，
本文编号：2421554
[Abstract]:Research purpose: the pit in the pit is a kind of asymmetric foundation pit which is widely used in engineering. At present, there are few related theoretical studies, and the influence range is often determined by experience in engineering design. In this paper, the deformation and earth pressure distribution characteristics of the pit type asymmetric foundation pit enclosure are discussed through finite element calculation and analysis, combined with the upper cantilever of the underground engineering of the Qingao axis in Nanjing and the foundation pit with inner support in the lower part. The aim is to provide reference for engineering design. The conclusions are as follows: (1) the distance of outer pit enclosure and the depth of pit excavation have significant effects on the deformation and force of the pit enclosure structure; (2) with the decrease of the distance between the outer pit and the inner pit, the deformation of the inner pit outside the pit decreases until it deviates to the pit. The external earth pressure of the inner pit enclosure can be calculated according to the outer pit surface and the safety factor can be considered to a certain extent. (3) with the increase of the excavation depth of the inner pit, the lateral displacement of the inner pit enclosure tends to increase, while the lateral earth pressure of the outer pit enclosure structure above the bottom of the pit is between the active earth pressure and the static earth pressure when the pit is not excavated or shallow; When the pit is deep, the earth pressure above the pit bottom is close to the active earth pressure until the bottom of the pit gradually approaches the static earth pressure. (4) the results of this study have reference value for the analysis and calculation of similar foundation pit engineering.
【作者单位】： 中铁第四勘察设计院集团有限公司;
【分类号】：TU753
，
本文编号：2421554
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