深圳填海造地深基坑开挖方案优选研究

发布时间：2018-03-03 09:31

本文选题：填海造地　切入点：深基坑　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来，大批填海造地工程出现在我国的沿海城市，越来越多的填海造地区深基坑工程需要建设。这些深基坑工程因填筑材料、填筑方法、基坑支护形式的不同，均存在不同程度的风险。因此，对特定的填海造地区域而言，，如何优化设计深基坑的开挖方案迫在眉睫。深圳湾是深圳市早期开发的填海造地区，本文研究的科技生态园二区深基坑工程位于深圳湾，属于典型的填海造地区深基坑工程。本文通过实地调研和文献分析相结合，对二区基坑开挖方案进行了初步设计。利用数值模拟方法进行基坑开挖全过程的计算，后采用改进的层次分析法构建基坑支护方案评价模型，融入模糊综合评判思想，确定了最优基坑开挖方案。本文的主要研究工作、成果和结论如下： ①通过勘查资料和国内外现状分析，总结出本基坑的特点和难点。本基坑开挖工作量大、开挖深度深、地下水丰富且周围环保要求高，参照以往填海造地区深基坑工程经验，初步设计三种基坑开挖支护方案； ②利用ANSYS完成基坑三维模型的建立实体建模和网格划分，后利用FLAC3D有限差分软件计算出三种支护方案在基坑开挖过程中的基坑位移、围护结构内力、位移数值模拟监测点水平位移。数值模拟结果作为主要参考点，提供技术性评价指标； ③深基坑支护方案的优选因素具有模糊性，传统的经验判断和层次分析法弊端较多，本文利用最优传递矩阵对层次分析法进行改进，并依据模糊数学原理建立该工程支护方案优选的综合评价模型，从技术性、经济性、环保性三个方面对初选的方案进行综合评判； ④计算三种支护方案的模糊综合评判结果，确定最优基坑开挖方案为桩锚支护方案。最后对本基坑开挖过程中土方开挖、监测体系和应急预案等方面，提出几点工程建议。
[Abstract]:In recent years, a large number of reclamation projects have appeared in coastal cities of China, and more and more deep foundation pit projects in reclamation areas need to be constructed. Therefore, how to optimize the design of deep foundation pit excavation is urgent for a specific reclamation area. Shenzhen Bay is a reclamation area developed early in Shenzhen City. The deep foundation pit project in the second area of the Science and Technology Ecological Park is located in Shenzhen Bay, which belongs to the typical deep foundation pit project in the reclamation area. The method of numerical simulation is used to calculate the whole process of foundation pit excavation, and the improved analytic hierarchy process is used to construct the evaluation model of foundation pit support scheme, which is integrated with the idea of fuzzy comprehensive evaluation. The optimal excavation scheme is determined. The main research work, results and conclusions are as follows:. The main contents are as follows: (1) the characteristics and difficulties of this foundation pit are summarized through the analysis of the survey data and the present situation at home and abroad. The excavation work of this foundation pit is large, the excavation depth is deep, the groundwater is abundant and the environmental protection requirement is high, referring to the experience of deep foundation pit engineering in the reclamation area in the past. Three kinds of excavation and support schemes are preliminarily designed. (2) the solid modeling and mesh division of the three-dimensional model of foundation pit are completed by using ANSYS, and then the displacement and internal force of the retaining structure are calculated by using the FLAC3D finite difference software during the excavation of the foundation pit. Displacement numerical simulation monitoring points horizontal displacement. The numerical simulation results as the main reference points to provide technical evaluation indicators; (3) the optimal selection factors of deep foundation pit support scheme are fuzzy, and the traditional experience judgment and analytic hierarchy process (AHP) have many disadvantages. In this paper, the optimal transfer matrix is used to improve the AHP. According to the principle of fuzzy mathematics, the comprehensive evaluation model of the optimal selection of the engineering support scheme is established, and the primary project is comprehensively evaluated from the aspects of technology, economy and environmental protection. (4) the fuzzy comprehensive evaluation results of three kinds of support schemes are calculated, and the optimum excavation scheme of foundation pit is determined as pile-anchor support scheme. Finally, some engineering suggestions are put forward in respect of earthwork excavation, monitoring system and emergency plan during the excavation of this foundation pit.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU753

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