Method and system for analyzing back-silting stability of foundation trench slope of submarine immersed tunnel

Abstract

The invention relates to a subsea immersed tunnel foundation trench slope back-silting stability analysis method and system, and the method comprises the steps: S1, setting wave flow field numerical parameters to construct waves, and obtaining the hydrodynamic pressure acting on the seabed surfaces inside and outside an immersed tunnel foundation trench; s2, rock-soil analysis parameters of a back-silting layer and a foundation trench seabed are set, a seabed rock-soil model near a foundation trench is constructed, and dynamic water pressure is applied to the seabed rock-soil model; s3, based on the rock-soil model of the seabed near the foundation trench, a strength reduction method is adopted for the seabed and a back-silting layer on the upper portion of the side slope, and the safety coefficient FOS of the most dangerous moment before desilting is obtained; and S4, setting dredging slope ratios with different numerical values, correspondingly modifying the rock-soil analysis parameters of the back-silting layer in the step S2, adopting a strength reduction method for the seabed and the back-silting layer at the upper part of the side slope, and obtaining a safety coefficient FOS at the most dangerous moment after dredging. The method can quantitatively evaluate the influence of back silting and desilting on the stability of the foundation trench slope in the marine environment.

Description

technical field [0001] The invention belongs to the technical field of marine engineering disaster assessment, and in particular relates to a method and system for analyzing the stability of back-silting of a foundation groove of a submarine immersed tunnel. Background technique [0002] The stability analysis of the slope of the subsea foundation trench is an important part in the design and construction of the subsea immersed tube tunnel, because it directly affects the amount of earthwork excavation and the amount of backfill after the immersed tube is laid down. With the successive construction of large-scale sea-crossing tunnels such as the Hong Kong-Zhuhai-Macao Bridge and the Deep-Central Channel in my country, the stability of the slope of the submarine foundation trench under complex geological and hydraulic conditions has attracted more and more attention. Under normal circumstances, under the premise of ensuring construction safety and quality, increasing the slop...

AI Technical Summary

Problems solved by technology

Most of the existing studies focus on the stability of slopes under still water conditions, and the studies considering the influence of wave or sea current loads in marine environments are very limited

[0004] At the same time, the silting intensity of the cross-sea immersed tube tunnel is high, and the time for drying the tank is long. If the silt returns to land during the construction of the cushion layer or the sinking of the immersed tube structure, it will seriously threaten the safety of the immersed tube tunnel.

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