Study On The Structural Performance Degradation Calculation Model Of Sewage Shield Pipeline

With the accelerated process of urbanization, the sharp growth of population and the rapid development of economy, the quantity of industrial waste water and domestic sewage increased year by year, and with the increase of service life, many pipeline collapse and sewage leakage accidents occurred due to the lack of durability,which resulted in a large number of money waste,also brought a lot of disadvantages to people’s production and living at the same time. Under this background, the mechanical properties and deformation of the tunnel under the urban sewage pipe are studied in this paper.Firstly, the composition of domestic wastewater is analyzed in this paper,the corrosion of segment concrete caused by sewage is summarized as chemical damage,physical damage and microbial destruction, the corrosion mechanism of each type of failure is summarized in detail. At the same time, the paper introduces the calculation theory of the shield pipe and the related computational load,which provide theoretical basis for the establishment and realization of the model.Through the research on the corrosion mechanism of sewage pipeline, the pipeline is divided into 3 different types of corrosion area. On this basis,the paper established a kind of mechanics performance calculation model for the drainage shield pipe segment structure which can take segment corrosion category difference,segment joint stiffness nonlinearity, stratigraphic constraints and multi temporal and spatial conditions into consideration, compiled finite element program and developed the application software based on GUI Matlab to provide a way to realize the model.In order to obtain the dynamic elastic modulus variation law of concrete segment in a sewage environment,which provide the basis for thedE assumption of AB region of calculation model, the paper designed indoor accelerated test, set the NaCl and2 4Na SO solution with the concentration gradient of 0%, 5% and 10%respectively,carried out research on the corresponding corrosion law of C50, C30 concrete under the condition of long-term soaking and drying-wetting cycle.Finally,for Guangzhou tunnel deep drainage system-Donghaochong test section project,using ‘the performance evaluation software for the whole life of the sewage shield pipeline’,the paper analyzed the internal force change and deformation process of sewage pipe under corrosive environment. The results show that: the internal forceof the sewage pipeline in the service life is constantly changing,and the variation range of different regions is different,what’s more, by analyzing the size and speed of the internal force change,we can know that the region B is the most unfavorable area.The existence of the segment joint weakens the lining stiffness and results in the increase of local displacement.