Evaluation Of Tunnelling Induced Ground Settlement Based On Data Mining Technology

Large-scale construction of subway system can ease the pressure on urban traffic, but inspire the geotechnical safety risk in urban area. There is an emergent need for a systematic way to accumulate engineering experience, to explore engineering rules and to implement engineering knowledge, because the geotechnical works are very complex. This dissertation follows the route of knowledge management technology and proposes a systematic method named’from data to wisdom’ to evaluate tunneling induced ground settlement which deserves most safety attention.This method not only contributes to the accumulation of experience in engineering, but also supports safety decision on site.First, a multidimensional data warehouse is established to facilitate the analysis of ground settlement and integrate the fragmented and heterogeneous data into valuable information. In the conversion process of data to information, a Logistic model is proposed to describe the growing pattern of ground settlement and solve the data missing problem by using non-linear regression and random imputation techniques.wavelet analysis method is also implemented to filter out the measurement error and enhance the quality of the data and the value of information.Then, the rules of ground settlement are explored in multiple perspectives andsome safety indicators are refined by usingthe data warehouse. In the conversion process of information to knowledge, the settlement trough model of twin-tunnel is proposed and Levenberg-Marquardt method is implemented to solve the problem of non-linear model fitting; the fitting results show the time invariance of the settlement trough width and its correlation with the distribution of the geological and hydrological condition; this dissertation also proposes the calculation method of ground loss and concludes its distribution and growth pattern.Finally, an early warning mechanism for ground settlement control is established to guide the engineering practice by comprehensively applying the proposed rules of ground settlement. In the conversion process from knowledge to wisdom, a method to scope the safety area is proposed by extending the rule of Gaussian distribution and adopting the proposed prediction method of the width of ground settlement trough; the statistical process control (SPC) method is also implemented to identify the outlier of ground settlement, ground loss and etc.