## 7 Conclusions  
The findings of the present research concerning model updating for a continuous concrete girder bridge using data from the construction monitoring are summarized below:  
1. The abundant data measured on bridges in construction stages can enhance the reference information for the more effective FE model updating of the structures. In addition, with the proposed model updating method utilizing data from the construction monitoring, the uncertain parameters with the initial FE model of the structure can be progressively and easily identified using many single-variable linear regression models, which are superior to one complicated multi-variable mathematical or numerical model employed by most traditional model updating approaches to simultaneously identify many uncertain parameters, as the latter generally leads to non-unique solutions rendered by normal optimization algorithms. 2. Based on the engineering case of Huangsha Harbor Bridge, it is demonstrated that the proposed model updating approach is effective in practical use, and it is superior to the traditional model updating method using structural responses of the built structure. It is calculated that the RMS error of static structural responses is 32.74% for the model of Huangsha Harbor Bridge updated using the new method and 41.07% and 38.48% for the initial model without model updating and the model updated using the traditional method, respectively. The improved accuracy of the model updated using the new method can be considered as an advantage of the proposed method compared to the analogue, i.e., the traditional model updating approach based on orthogonal experimental design and support vector regression (SVR). Since Huangsha Harbor Bridge's FE model is complicated, the sensitivity-analysis-based model updating approach is inapplicable due to its high computational costs, and the surrogate-model-based model updating approach of high computing efficiency is attempted for the traditional model updating approach. Sampling based on orthogonal experimental design and surrogate model establishment based on SVR are undertaken for the  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{ \begin{tabular}{c} **Along-** \\ **Bridge** ** **Position (m)** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **Full-Scale** \\ **Altitude (m)** \\ \end{tabular}  } & \multicolumn{2}{c}{ \begin{tabular}{c} **Initial Model without Model** \\ **Updating** \\ \end{tabular}  } & \multicolumn{2}{c}{\ \begin{tabular}{c} **Model Updated Using the** \\ **Proposed Method** \\ \end{tabular}  } & \multicolumn{2}{c}{ \begin{tabular}{c} **Model Updated Using the** \\ **Traditional Method** \\ \end{tabular}  } \\ \cline{3-8}  & & & **Altitude (m)** & **Relative** **Error (\%)** & **Altitude (m)** & **Relative** **Error (\%)** & **Altitude (m)** & **Relative** **Error (\%)** \\ \hline
86.2 & 0.  
traditional model updating to take place. This model updating approach is indicated as the alternative method as a basis for the comparison. 3. The deviation in the stress measured on the continuous concrete girder bridge due to the uneven temperature can be compensated for using the approach adopted by the present research. In addition, stresses measured in concrete using vibrating wire stress transducers might be inaccurate when the vibrating wire stress transducers are used over a certain period. The stress arrays measured using the technique on continuous concrete girder bridges under construction using the symmetric cantilever casting method can be updated based on the GM (1,1) models. It should be noted that the during-construction properties change during the construction process for a structure under construction, and the data from the built structure must be different from those measured from the being-built structure. Therefore, the during-construction data are not valid after the construction is completed.