Risk Assessment to the High Speed Railway Bridge during the Construction of Underpass Bridge

To ensure the safety of the high-speed railway bridge influenced by the excavating and dewatering work of the underpass bridge, risk assessment research had been put into practice in Cuiheng Road underpass of the Beijing-Tianjin intercity railway. Combining the quantitative and the qualitative analysis, the fatality analysis method was introduced to acquire an explicit conclusion and for available suggestions. First, the risk sources, the probability of occurrence, and the approximate degree ofharm were researched by the specialist consultation and the risk committee. Aimed to find kernel risk sources, such as excavating and dewatering construction, the finite element models (FEMs)were used to acquire the deflections of the bridge foundation and the approach embankment in various conditions. The ALARP principle was introduced to determine the risk assessment results. Safety control means were researched, and the twin row waterproof curtain by jet grouting piles and full bottom sealing by soil-cement mixing piles were suggested to achieve the target of feebleness disturbed deflection. The ARIMA method was applied in the settlement forecasting, and the indicator system for a security alarm was suggested to those monitoring construction work.