考虑实测沉降数据新旧程度的软基工后沉降预测方法

发布时间：2018-05-27 00:44

本文选题：工后沉降 + 沉降预测　；参考：《湖南大学》2015年硕士论文

【摘要】：建筑物地基或路基的沉降预测一直是土木工程界所关注的热点问题之一,也是土力学研究中的重要课题之一。对于目前已有的沉降预测方法而言,主要有基于本构模型的数值分析方法与基于现场实测沉降数据的数学分析法两大类。而由于基于本构模型的数值分析方法在实际工程中往往具有地基参数难以确定、本构模型与工程实际存在一定的差别,且往往还需要进行大量复杂的参数反演分析计算等缺点,因而该类方法在实际工程中也往往难以推广使用；因此,对于具有计算操作便捷,具有很强的工程实用性特点的基于实测沉降数据的数学分析方法便成为了建筑物地基或路基沉降预测中使用得最广泛的方法。目前,基于实际工程现场实测沉降数据的数学分析方法已经得到了广泛而深入的研究,且取得了系列卓有成效的研究成果,但仍存在在预测过程中未充分考虑实测沉降数据新旧程度等的局限性与不足。因此,本文以沉降预测的数学拟合分析方法为基础,在考虑实测沉降数据新旧程度在预测过程中的不同有效性的前提下,提出基于实测数据新旧程度的工后沉单项预测与组合预测新方法。首先,针对实测沉降数据新旧程度对预测效果的影响,引入新鲜度函数,对单项预测模型沉降计算值与实测值之间的误差进行修正,建立出单项预测模型拟合分析的新型误差目标函数,并在此基础上,提出了基于实测沉降曲线拟合分析确定单项沉降预测模型参数的新方法,进而提出了反映实测沉降数据新旧程度影响的单项模型工后沉降预测新方法。然后,在此基础上引入组合预测的思想,并通过研究沉降组合预测可能取值的变化规律,引进平行修正的思路,建立出利于提高沉降组合预测精度的组合预测可能取值区间的调整方法,提出了同时考虑实测沉降数据新旧程度和组合预测可能取值区间调整对预测效果影响的改进工后沉降组合预测新方法。最后,通过工程实例的计算与分析,以及与实测值和其他现有相关方法的计算结果比较,可以验证本文改进的工后沉降单项预测方法与组合预测方法的可行性和合理性。
[Abstract]:The settlement prediction of building foundation or subgrade has been one of the hot issues in civil engineering field, and it is also one of the important subjects in soil mechanics research. For the existing settlement prediction methods, there are two main categories: the numerical analysis method based on constitutive model and the mathematical analysis method based on the field measured settlement data. Because the numerical analysis method based on constitutive model is difficult to determine the foundation parameters in practical engineering, there are some differences between constitutive model and engineering practice, and a large number of complex parameter inversion analysis and calculation are often needed. Therefore, it is difficult to popularize this kind of method in practical engineering. The mathematical analysis method based on measured settlement data with strong engineering practicability has become the most widely used method in the prediction of building foundation or subgrade settlement. At present, the mathematical analysis method based on the field measured settlement data has been extensively and deeply studied, and a series of fruitful research results have been obtained. However, there are still some limitations and shortcomings in the prediction process, such as the new and old degree of measured settlement data are not fully considered. Therefore, based on the mathematical fitting analysis method of settlement prediction, considering the different validity of the new and old degree of measured settlement data in the prediction process, A new method of single item prediction and combination prediction of post-construction subsidence based on the new and old degree of measured data is proposed. Firstly, aiming at the influence of the new and old degree of the measured settlement data on the prediction effect, the freshness function is introduced to correct the error between the settlement calculation value and the measured value of the single prediction model. A new error objective function for fitting analysis of single prediction model is established. On this basis, a new method for determining the parameters of single prediction model based on the fitting analysis of measured settlement curve is proposed. Furthermore, a new method for predicting post-construction settlement of single model is proposed, which reflects the influence of new and old degree of measured settlement data. Then, on this basis, the idea of combination prediction is introduced, and the thought of parallel correction is introduced by studying the law of variation of the possible values of settlement combination prediction. An adjustment method is established to improve the accuracy of the combined settlement prediction, which is helpful to the adjustment of the range of the possible values of the combined settlement prediction. A new method for prediction of post-construction settlement combination is proposed, which takes into account the influence of the new and old degree of measured settlement data and the possible interval adjustment of combination prediction on the prediction effect. Finally, the feasibility and reasonableness of the improved single prediction method and combination forecasting method of post-construction settlement can be verified by the calculation and analysis of engineering examples and the comparison of the calculated results with the measured values and other existing relevant methods.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU433

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