【作者】 夏银飞；

【导师】 张季如；

【作者基本信息】 武汉理工大学 ， 岩土工程， 2004， 硕士

【摘要】 软土路基变形比较复杂，影响因素众多，从软土路基变形机理出发来建立模型，并对路基变形进行拟合和预测是困难的。本文从实测变形数据出发，利用数据中所蕴含许多信息，来建立沉降模型。 本文的主要内容如下： (1)介绍了软土路基稳定与变形的基本特性和机理，总结了软土路基变形预测的必要性，分析了软土路基变形预测的难点和存在的问题，简要介绍了时间序列的优缺点以及应用的广泛性。 (2)详细阐明了时间序列的基本思想、几种常见的时间序列模型以及时间序列的动态特征，分析了如何利用自相关函数和偏相关函数来对模型进行判定，通过对时间序列的几种定阶准则的比较，确定一种好的定阶准则来建立模型，从而可以利用逆函数法进行预报。 (3)介绍了混沌时间序列的研究意义，阐述了混沌时间序列的基本理论以及三种预测模式，确定了最大Lyapunov指数的计算步骤。 (4)从路基实测变形数据出发，将时间序列非平稳性模型(ARIMA模型)转化成时间序列平稳模型(ARMA模型)，通过模型识别、参数估计、模型验证等步骤来建立模型，从而进行路基动态变形预测，利用路基变形的控制标准对路基下一级填土的时间进行预测，优化了施工组织设计，节省了时间和资金。 (5)路基超载完成后，在路基荷载稳定期间内，利用混沌时间序列中的最大Lyapunov指数和全域法进行长期预测，同时与一些比较成熟的变形预测方法进行对比，对工程中一些重点断面进行综合评判，确定一个较理想的预测结果，从而对路基超载进行卸载，使其满足工程设计要求。 时间序列预测方法虽广泛的应用于各行各业，并取得了比较好的效果，但是在预测高速公路路基变形方面应用较少，尤其是用于填土期间的变形预测罕见报道，本文作者在这方面作了一些开拓性的工作。更多还原

【Abstract】 The warp of soft soil foundation is much complicated and the factors affected are much more. It’s difficult to fit and predict the warp of road foundation just from the model setted up from the warp principle itself. The thesis stars from the warp material got in the practice,and sets up the road warp model from the much information that affects the warp factors.The main content of the thesis is as the following:(1) It states the basic peculiarity and the principle of the steady of road foundation and the warp settlement, sums up the necessity of the predict of soft soil road foundation warp, analyses the difficulty and the questions unsolved existing in the predict of soft soil road foundation settlement,and simply introduces both the advantages and disadvantages and the wide utilization of time series.(2) It explains the basic concept of time series, some kinds of the common time series models and the development characteristics of time series in detail. It analyses how to judge the model from the self-related function and the deviation related function. Determining a better standard to set up models from the comparison of some kinds of fixed step time series standards, then predicts utilizing the counter function.(3) It introduces the study significance of chaotic the time series, explains the basic theory and three kinds of predict models of the chaotic time series, and makes sure the step that counts the biggest index number Lyapunov.(4) The thesis converts unrest model (ARIMA model )of time series to the rest model (ARMA model ) of time series. It sets up models acrossing some procedures, such as model identify, factor estimation, model check, ect, then predict the development short-term warp of road foundation. It predicts the time of the filling soil of the next grade utilizing the growth theory of the strength of the road foundation, assures that the working organization and design go smoothly during the filling work of road foundation and saves time and money.(5) Another is the long-term predict utilizing the biggest index number Lyapunov in the chaotic time series and the whole space method during the steady period of the road foundation load, after the overload of the road foundation finished. Meanwhile, contrasts with some mature settlement predict methods, estimating some important section in the engineering synthetically, making sure an ideal outcome of the predict warp, then unload the overload ofroad foundation and make it satisfy the design request.Though the predict methods in the thesis are widely used in every field and acquire better consequence, but the methods using in the predict of the high way road foundation warp are little, especially reported little in the settlement predict during the period of filling soil. The author of the thesis does some pioneer study on it.更多还原