Analysis and countermeasures of surface settlement of buildings undercrossing large section loess tunnels
This article is based on an engineering example of a loess tunnel passing through the surface of a building(structure)on the West Extension High Speed Railway,using theoretical analysis,numerical simulation and other meth-ods,this study investigates the range and countermeasures of surface settlement during the construction of large-section lo-ess tunnels passing through surface buildings.The results indicate that:Based on the theory of random media,the surface settlement range on both sides of the tunnel can be divided into strong,weak,and no impact zones.The strong impact zone of tunnel construction on the surface is approximately equal to the depth of the tunnel,while the weak impact zone is about twice the depth of the tunnel;When the excavation surface reaches directly below the office building,the settlement value of the office building accounts for about 70％of the total settlement value;After passing through the office building,the settlement rate tends to converge.During tunnel construction,it is necessary to strengthen the construction quality of buildings(structures)close to the surface to ensure the safety of the surface structure;After the tunnel passes through the surface buildings,the surface settlement tends to converge,but the settlement value continues to increase.After the tun-nel passes through the surface buildings,the settlement deformation of the buildings should be continuously carried out,and the second lining of the palm face should follow closely to ensure the structural safety of the surface buildings;When a large cross-section loess tunnel passes through surface buildings,measures such as the three step temporary arch(waist beam)method,locking foot reinforcement,and initial support reinforcement can be adopted to ensure the safety of tunnel construction.These measures can provide reference significance for the construction of similar projects.
large section loess tunnelbuildingssurface subsidenceaffected area
万方数据
维普
