深基坑开挖时周边建筑物沉降预测及数值模拟研究

发布时间：2018-11-19 18:57

【摘要】：随着我国经济飞速发展,全国各地出现了许多大型的深基坑工程,其中很大一部分处于城市中心,基坑工程的施工必然会使周边建筑物发生变形,同时带来一些安全隐患。实时地对建筑物进行监测、分析和处理实测的变形数据,并针对基坑开挖运用合适的预测方法对建筑的变形进行预测,是在基坑施工期间保证周边建筑物安全的重要手段。现在对于变形分析的研究内容一般分为变形的物理解释和几何分析两部分。变形的物理解释的任务是建立变形体的变形和变形原因之间的关系,解释变形的原因。几何分析的任务是在各种荷载作用下描述变形体变形的空间状态和特性。针对深基坑开挖导致的建筑物变形问题,本文首先通过改进的灰色系统模型对数据进行处理；其次结合BP神经网络模型的自学习性强的特点,对改进的灰色系统模型的预测误差进行改正。通过对其精度的分析可知,该组合模型对建筑物变形的预测可以达到很高的精度；最后,本文基于深基坑开挖前的地质资料,运用有限差分软件FLAC3D建立深基坑支护结构、周围土体和建筑物的简化模型,并通过深基坑工程开挖初期建筑物的变形监测资料对该模型参数进行优化,并根据该模型对深基坑开挖进行模拟,对建筑物上的监测点做预测,其预测结果稍大于实测结果。
[Abstract]:With the rapid development of economy in China, many large deep foundation pit projects have appeared all over the country, most of which are located in the center of the city. The construction of foundation pit engineering will inevitably make the surrounding buildings deform and bring some hidden dangers to safety at the same time. It is an important means to ensure the safety of surrounding buildings to monitor the buildings in real time, to analyze and process the measured deformation data, and to forecast the deformation of the buildings by using the appropriate prediction method for the excavation of the foundation pit. Now the research on deformation analysis is divided into two parts: physical interpretation and geometric analysis. The task of physical interpretation of deformation is to establish the relationship between deformation and its causes, and to explain the causes of deformation. The task of geometric analysis is to describe the spatial state and characteristics of deformation under various loads. Aiming at the problem of building deformation caused by deep foundation pit excavation, this paper deals with the data through the improved grey system model. Secondly, the prediction error of the improved grey system model is corrected based on the strong self-learning characteristic of BP neural network model. Through the analysis of its precision, it can be known that the combined model can predict the deformation of buildings with high accuracy. Finally, based on the geological data before excavation of deep foundation pit, a simplified model of supporting structure, surrounding soil and building of deep foundation pit is established by using finite difference software FLAC3D. The parameters of the model are optimized by the deformation monitoring data of the building in the early stage of excavation of deep foundation pit. According to the model, the excavation of deep foundation pit is simulated, and the monitoring points on the building are forecasted, and the prediction results are slightly larger than the measured results.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU433

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