Study On The Durability Of The Concrete Wall Of The Underground Traffic Engineering In Tianjin

Underground traffic engineering design life of100years, the durability of concretestructural material directly related to the life and security of the entire undergroundtransport project. In this paper, the construction of underground transport projects in TianjinMetro Line2and3, to study the durability of concrete and underground concrete wall toguide the actual construction and construction engineering. The main work is as follows:Firstly, the combination of geological prospecting of Tianjin metro line2and3, Idetailedly investigate, analyze, and grading the ion erosion corrosion of concrete structureby Tianjin sea water, diving, and micro artesian water. According to the requirements of thegeological prospecting specification grading, the concrete corrosion level by the sea water,diving, and micro artesian water in Tianjin region is medium. The corrosion of concrete bythe shallow groundwater and soil is more serious, mainly D level, local level E.Secondly, I detailed analyze the corrosion mechanism of groundwater on thereinforced concrete structure in coastal erosion,mainly includes the carbonation, ion erosionand freeze-thaw erosion mechanism.Thirdly,according to the metro design specification and the mixture ratio designprinciples and requirements, I optimize the raw materials in Tianjin area. Combining withthe characteristics of each component force, water environment and water quality, the paperdesigns and optimizes the mixture ratio indoor. By using the method of orthogonal analysis,design the reference mix and contrast ratio, and indoors comprehensive performance testand optimize including concrete strength,frost resistance,permeability resistance,resistanceto ion invasive,etc.Get to meet the requirements of grade D corrosion C30concrete.Fourthly,based on the optimized proportion, simulate the construction entity wallcasting experiment, applying horizontal load on the test wall (analog component entities),and performance test under the different age on the test wall face soil surface and back soil.Permit test trials using the chloride permeability of the wall at different ages, through thetest wall tension and compression stress and deformation allows chloride permeabilityunder extreme conditions, verification optimization with resistance to chloride ionpermeability than concrete.