广州保利冼村旧城改造深基坑支护设计及数值模拟分析

发布时间：2018-03-10 04:21

本文选题：基坑工程　切入点：支护结构设计　出处：《东华理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：深基坑工程是城市发展繁荣和进步后的必然产物,它所涉及的问题多广杂,并且要求技术先进。深基坑工程也是一项复杂的、高风险的系统工程,涉及学科较多,有工程地质、水位地质学、土力学、流体力学、工程力学、结构力学、环境科学等,具有非常强的综合性及诸多影响因素。随着城市建筑物越来越多及旧城区改造,基坑工程开挖空间有限,对基坑工程要求较高,在保证自身安全使得地下工程能顺利进行同时,还需要保证周边建筑物、管线、道路等安全。研究深基坑工程在施工中应力应变、变形及其稳定性具有重要的实际意义。本文以广州保利冼村旧城改造深基坑工程为背景,采用理正软件及FLAC3D软件进行论文深基坑支护设计及模拟计算,并将计算结果与工程实际监测进行对比分析,两者之间存在一定差异,但整体吻合度较好,验证了数值模拟方法在深基坑工程中的实用性。本文研究了基坑分步开挖过程中,基坑支护结构的水平位移、竖直位移、预应力锚索轴力、支护桩弯矩、基坑土体塑性区等变化特点,主要详细研究内容:(1)本文以广州保利冼村旧城改造深基坑工程为例,首先用FLAC3D软件模拟无支护条件下基坑开挖过程的变形特征及其应力分布,并找出其受力薄弱部位,运用理正软件有针对性地进行基坑支护设计计算,得到快速优化设计,提高了工作效率,也探索了两个基于不理论方法的计算软件的优点结合,验证了本深基坑工程采用桩锚支护的合理性;(2)在FLAC3D模拟基坑开挖过程,对基坑水平位移、地表沉降及锚杆内力进行模拟监测,数值模拟软件监测结果与实际过程监测数据进行对比存在一定差异,主要原因是岩土参数离散性大、数值模拟难以时空效应及难以将诸多影响因素综合考虑,但发展趋势及数量结果与实际监测数据较吻合,验证本深基坑工程数值模拟的合理性及可行性,为本地区或相类似的深基坑工程提供参考;(3)通过FLAC3D采用强度折减系数法对基坑边坡进行稳定性分析,结合理正深基坑设计软件基坑整体稳定性分析、抗倾覆稳定性分析及抗隆起稳定性分析对比,运用多种方法评价基坑稳定性,提高了稳定性分析的可靠度。
[Abstract]:Deep foundation pit engineering is an inevitable product of urban development, prosperity and progress. It involves a wide variety of problems and requires advanced technology. Deep foundation pit engineering is also a complex, high-risk system engineering, involving more disciplines, engineering geology, Water level geology, soil mechanics, fluid mechanics, engineering mechanics, structural mechanics, environmental science and so on, have very strong comprehensive and many influence factors. In order to ensure the safety of underground engineering, it is necessary to ensure the safety of surrounding buildings, pipelines, roads and so on. Deformation and its stability are of great practical significance. Based on the reconstruction of deep foundation pit in the old city of Pouli Xian Village in Guangzhou, this paper adopts the software of Lizheng and FLAC3D to carry out the design and simulation calculation of deep foundation pit support. The comparison and analysis between the calculation results and the engineering monitoring results show that there are some differences between the two, but the overall consistency is good, which verifies the practicability of the numerical simulation method in the deep foundation pit engineering. In this paper, the step-by-step excavation process of the foundation pit is studied. Horizontal displacement, vertical displacement, axial force of prestressed anchor cable, bending moment of supporting pile, plastic zone of soil of foundation pit and so on. The main research contents of this paper are as follows: (1) this paper takes the transformation of deep foundation pit in the old city of Pouli Xian village in Guangzhou as an example. First, FLAC3D software is used to simulate the deformation characteristics and stress distribution in the excavation process of foundation pit without support, and to find out the weak position of the stress, and to carry out the design calculation of foundation pit support with the proper software, and to obtain the rapid optimization design. The efficiency is improved, and the advantages of two calculation software based on non-theoretical method are explored. The rationality of adopting pile and anchor support in this deep foundation pit engineering is verified, and the horizontal displacement of foundation pit is simulated in FLAC3D. Ground subsidence and anchor internal force are simulated and monitored. The results of numerical simulation software are different from the actual monitoring data. The main reason is the large dispersion of geotechnical parameters. The numerical simulation is difficult to take into account the space-time effect and the influence factors, but the development trend and the quantity result are in agreement with the actual monitoring data, which verifies the rationality and feasibility of the numerical simulation of the deep foundation pit engineering. This paper provides a reference for local or similar deep foundation pit engineering. Through FLAC3D, the stability analysis of foundation pit slope is carried out by using strength reduction coefficient method, and the overall stability analysis of foundation pit is combined with Lizheng deep foundation pit design software. Compared with the stability analysis of anti-overturning stability and anti-uplift stability, a variety of methods are used to evaluate the stability of foundation pit, which improves the reliability of stability analysis.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.2

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