【作者】 罗孝敏；

【导师】 刘畅；

【作者基本信息】 天津大学 ， 结构工程， 2012， 硕士

【摘要】 近年来,为了保证基坑开挖能够安全进行,许多学者和技术人员对基坑工程展开了大量的研究。一方面,基坑开挖深度的增加和开挖面积的增加对安全施工提出了更高的要求,基坑工程需要满足围护结构本身的安全性和稳定性。另一方面,城市建设工程的集中性导致基坑工程所面临的环境日趋复杂,基坑工程还需要满足周边环境的安全性。由于城市轨道交通建设的需要,交叉型基坑的施工也逐渐增加,交叉基坑施工复杂,施工时不仅要考虑支护结构的强度要求,还要考虑交叉基坑的变形要求。因此,对交叉型深基坑的变形特性进行分析也显得十分必要。本文以PLAXIS为主要计算工具,对于家堡站交通枢纽工程中大型基坑开挖进行了二维数值模拟和三维数值模拟。并且结合施工现场监测数据,进行了基坑变形特性的研究,主要包括地下连续墙水平位移,坑内土体隆起,坑外土体的沉降等。通过对比分析验证了三维数值模拟的合理性和基坑开挖的空间效应。本文对B1线隧道与海河隧道交叉基坑开挖施工工况进行了数值模拟,并且结合现场监测数据,对交叉型基坑开挖的变形特性作了一定的分析。最后,本文针对交叉型基坑开挖时墙体交叉处容易发生破坏的问题,对坑角处采取了一定的加固措施,并且取得了良好的效果。更多还原

【Abstract】 In recent years, in order to guarantee the excavation’s security, many scholars and technical personnel have launched a lot of research in excavation engineering. On one hand, the increase of the depth of excavation and the increase of excavation area are demanding more for security in construction. Excavation engineering needs to meet palisade structure’s security and stability. On the other hand, the centralization of the urban construction engineering makes the environment of excavation engineering more complicated, and excavation engineering also needs to meet the security of the surrounding environment. Due to the needs of the construction of urban rail transit, the construction of crossed excavation engineering is gradually increasing. Considering its complexity, we should pay attention to the requirement of the strength of the supporting structures, but also the requirement of the deformation. Therefore, it is necessary to analysis the deformation characteristics of the deep crossed excavation engineering.This paper, using PLAXIS as the main computing tool, evaluates two dimensional finite element analysis and three dimensional finite element analysis of the excavation engineering in Yujiapu traffic hub project. And basing on the monitoring data in construction site, this paper researches the deformation characteristics of excavation engineering, including horizontal displacement of the underground diaphragm wall, and vertical displacement of soil in the bottom of the foundation pit, soil settlement near the foundation pit, and so on. Through the comparison and analysis of the results, it confirms the rationality of three dimensional finite element analysis and the spatial effect of foundation pit excavation. This paper evaluates finite element analysis of the Haihe river tunnel and B1 line tunnel cross-shaped excavation engineering, and analyzes the deformation characteristics of the cross-shaped foundation pit excavation, combining with the monitoring data. Finally, this paper takes some reinforcement measures to solve the problem of the junction of cross-shaped excavation engineering wall, and achieves good effect.更多还原