# Reliability Analysis of the Main Pier during the Construction Period of HLCR Bridges
## 4 Conclusions  
In this paper, the existing specifications and related literature were presented. The reliability of the main pier body of an HLCR bridge during cantilever cradle construction was studied. The main conclusions are as follows:  
1. Combined with the design of the HLCR bridge hanging cradle construction and the characteristics of the cantilever construction, the influencing factors of the bearing capacity were determined. The main influencing factors are the uncertainty of the resistance calculation mode, material parameters, the dead load and the live load. 2. According to the design scheme of the main beam of the HLCR bridge and the technological process of cantilever cradle construction, the structural stress characteristics and failure forms were analyzed in detail. The resistance and action effect models of the main pier under the two most unfavorable conditions were established: (1) There is no abnormal strong wind during the pouring of the last beam section; (2) The last block is poured and reaches the maximum cantilever. At this time, abnormal wind action occurs. Based on these two combinations, a reliability analysis was carried \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{2}{c}{\(k_{p1}\)} & \multicolumn{2}{c}{\(k_{mn}\)} & \multicolumn{2}{c}{\(k_{\mathrm{G}}\)} \\ \hline \multirow{2}{*}{**Average**} & \multicolumn{2}{c}{**Reliability**} & \multirow{2}{*}{**Average**} & \multicolumn{2}{c}{**Reliability**} & \multirow{2}{*}{**Average**} & \multicolumn{2}{c}{**Reliability**} \\  & **Indicators** & & & **Indicators** & & **Indicators** \\ \hline  
\hline \hline \end{tabular}
\end{table} 
Table 7: Effect of the mean value of each parameter on the strength reliability index under combination II. \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Variables**} & \multicolumn{2}{c}{**Hanging Cradles Work**} & \multirow{2}{*}{**Hanging Cradle Falls**} \\  & **Properly** & \\ \hline \(\beta_{1}\) & 11.1585 & 11.1585 \\ \(\beta_{2}\) & 6.7138 & 6.3056 \\ \(\beta_{3}\) & 11.1611 & 11.1611 \\ \(\beta_{4}\) & 6.227 & 5.8423 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Influence of the working condition of the hanging cradle on the reliability index. out, which laid the foundation for reliability analysis of the bridge pier during the construction period. 3. Based on a river-crossing bridge, the reliability function of a cantilever hanging basket during the construction period was established. We utilized MATLAB software to calculate the reliability index for the main pier during the cantilever construction of the bridge girder by using the JC method. The accuracy of the above analysis was proven, and we verified that the construction process for this project has a sufficient safety margin. 4. Closely combined with the reliability theory, changes in the statistical parameters of various influencing factors were analyzed for their degree of influence as structural reliability indicators, and it was found that the construction distributed live load has a relatively small influence on the reliability of bridge pier during the construction period. The actual construction can be controlled as little as possible to avoid delaying the construction period. Yet, a change in wind load parameters has a relatively large impact on the reliability of piers at the maximum cantilever, so it is necessary to avoid windy weather during construction. A fall of hanging cradles during construction, increase in resistance, change in the statistical parameters of the structural constant load and the performance of concrete materials all largely affect the reliability of piers and need to be controlled during construction, which provides a reference for the construction of subsequent such projects. In this paper, our research on the reliability of an HLCR bridge during construction achieved phased results, but there are still areas to be considered and improved.