Abstract： Rock cover for subsea tunnel has direct influence on the economy and safety of tunnel project, so how to determine the rock cover is one of the key problem of tunnelling crossing the unfavorable geological bodies. Aiming at this problem, typical subsea tunnel water inrush accidents worldwide are first analyzed, furthermore the physical significance of “limited rock cover” are clarified. Combining the mutual restriction characteristic of reasonable grouting reinforcement parameters and the rock cover, the determination method of limited rock cover is proposed, in which the core is determination of the thickness of plastic zone and reasonable grouting reinforcement. The mechanical model of subsea tunnel surrounding rock considering advanced reinforcement and seepage effect is proposed. Based on the possible distribution of plastic zone(s), surrounding rock are theoretically analyzed. On the basis of the given calculation formulas, the sensitivities of reinforcement parameters are analysed. Taking the minimum surrounding rock displacement and the lowest seepage volume as the targets, the reasonable determination method of solving the reinforcement ring parametric multi-objective optimization problem of subsea tunnel is proposed based on the stratified sequencing method to determine the optimal limited rock cover. The method has been applied in Jiaozhou Bay subsea tunnel, whose rationality and feasibility are verified, providing the theoretical basis for the planning and safe construction of subsea tunnels.
孙振宇 张顶立. 基于地层加固的海底隧道极限顶板厚度确定方法[J]. 土木工程学报, 2020, 53(9): 115-128.
Sun Zhenyu Zhang Dingli. Determination method of limited rock cover for subsea tunnel#br#
based on ground reinforcement. 土木工程学报, 2020, 53(9): 115-128.
