A lateral pressure prediction model for bottom-up pumping of SCC in large-diameter steel tubes based on Bernoulli's Principle

The utilization of bottom-up concrete pumping technology has become popular in the construction of concrete-filled steel tube arches. Additionally, self-compacting concrete has extensive usage in pumping construction projects. During the process of bottom-up pumping, the self-compacting concrete exerts lateral pressure on the inner wall of steel tube. Excessive lateral pressure can lead to the deformation and failure of steel tube. This paper aims to introduce a reliability-based prediction model for calculating the lateral pressure in the case of bottom-up pumping self-compacting concrete. The prediction model was founded upon the assumptions of viscous flow and the Bernoulli’s principle. Within this model, an equilibrium equation considering viscous loss was formulated and subsequently solved by using the Newton iteration method. Moreover, a bias function was incorporated into the equation to ensure precise solutions. Based on these solutions of equations, the probability density distributions of lateral pressure at various vertical heights were obtained. Then, lateral pressure prediction was achieved by establishing a specific probability as the standard for prediction. Finally, The effectiveness of this prediction model was validated through a comparison between the lateral pressure data obtained from prior full-scale tests and the predicted values. The results demonstrate that the prediction model is capable of predicting the lateral pressure with a reserve of safety. The stability of prediction performance increases when the vertical heights of the self-compacting concrete are higher than 10 meters.