Shield tunnel river foundation deformation analysis and construction scheme optimization based on orthogonal test
The construction of shield tunnel is prone to trigger the loosening and collapse of the upper layer of soil at the excavation surface,causing settlement damage to adjacent buildings.To address the problem of ground deformation in shield tunnel construction,a finite element model was established to simulate the shield tunnel excavation process based on the Nanjing West Jianning Road river crossing project,and to investigate the effects of shield tunneling on riverbed settlement,horizontal and vertical displacements of the deep soil.The L16(45)orthogonal test was arranged with the maximum settlement of riverbed surface,settlement influence range,vertical displacement of vault top and tunnel bottom uplift as indicators,support stress ratio,burial diameter ratio,shield tail grouting pressure and relative density of mud as influencing factors,and the significance and order of each influencing factor were analyzed.The most economical level can be adopted.The optimal level combination is A4 B1 C4 D3 and A4 B2 C4 D3,and the optimized additional test is designed.The additional test scheme 1 reduces the burial diameter ratio and increases the shield tail grouting pressure,and the results show that it has a better effect on the control of formation deformation and is the preferred scheme for this project.
国家科技期刊平台
NSTL
万方数据
维普
