Spacing Analysis of Casting Dolly Windows for Tunnel Sidewall Lining Based on the Flow Characteristics of Freshly Mixed Concrete

Materials (Basel). 2024 Apr 14;17(8):1800. doi: 10.3390/ma17081800.

Abstract

During the actual construction of tunnel sidewall lining, construction workers often use only one or two windows per layer for pouring in order to reduce the construction sequence, which often leads to a reduction in the quality of tunnel sidewall concrete pouring. Therefore, this study analysed the necessity of the window-by-window pouring of sidewall lining through the study of concrete flow characteristics of the tunnel sidewall lining pouring process, and the reasonable spacing of pouring windows was analysed. This study firstly verified the accuracy of the simulation parameters and the feasibility of the simulation method of the lining pouring process through indoor experiments and simulation analyses, and then it numerically simulated and analysed the flow of concrete during the lining pouring process of tunnel sidewalls. The following conclusions were made: the smaller the slump of the freshly mixed concrete, the higher the pumping flow rate; additionally, the shorter the one-time pouring distance, the smaller the spacing of the trolley feeding window should be. Furthermore, this study makes suggestions for the reasonable spacing of pouring trolleys under several working conditions.

Keywords: analysis of dolly window spacing; flow characteristics; fresh concrete; sidewall pouring; tunnel engineering.

Grants and funding

This research was funded by the Shandong Province Road and Bridge Group Co., Ltd., under the following scientific research topics: research and application of complete sets of technologies for the prevention and control of tunnel lining dehollowing and disease management in mountainous mountain tunnels, and research on the method of secondary lining quality control and key technologies of tunnels based on comprehensive monitoring.