Method for determining longitudinal anti-seismic value of underground structure

Abstract

According to a method for determining the longitudinal anti-seismic value of an underground structure, a sandy soil liquefaction constitutive is adopted to assign values to soil layer material parameters, conversion of the sandy soil liquefaction constitutive from theoretical application to practical application is completed, and combination of three-dimensional free field nonlinear seismic effect analysis and underground structure longitudinal shell-spring model anti-seismic analysis is achieved; soil spring displacement time history assignment is achieved through underground structure cross section displacement time history extraction penetrating through a three-dimensional free field, so that an underground structure longitudinal anti-seismic numerical value is obtained; the forms of pipe joint shell units are rich, the annular section of a shield tunnel type can be calculated, and the square section of an immersed pipe and a pipe gallery type can also be calculated; and meanwhile, assignment is carried out by establishing a soil body model, the stress condition of the underground structure can be truly reflected, and the application scene is wide.

Description

technical field [0001] The invention relates to a method for determining the longitudinal anti-seismic value of an underground structure, which belongs to the technical field of research on anti-seismic measures of shield tunnels. Background technique [0002] With the development of my country's economy and the improvement of comprehensive national strength, the development of underground engineering in large and medium-sized cities has accelerated, and the scale of tunnel construction in my country has developed rapidly. Many of these tunnels are located in strong earthquake areas. Once a strong earthquake occurs, the safe operation of the tunnel will be seriously threatened, causing heavy casualties and huge economic losses. Therefore, it is particularly important to carry out research on the seismic response characteristics of underground tunnels under strong earthquakes. [0003] In order to solve the longitudinal seismic response of large shield tunnels under strong ea...

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Problems solved by technology

Due to the limitations of the two-dimensional free-field numerical model, it is impossible to fully extract the three-dimensional parameters of the soil spring, let alone the multi-directional displacement response around the tunnel, and it is impossible to consider the geometric inhomogeneity of the three-dimensional space of the soil

In addition, the constitutive model adopted in the above paper is only the constitutive model of the total stress method, which cannot consider the influence of soil liquefaction. At the same time, the beam-spring model cannot observe the local details of the structure. However, shield tunnels have a long longitudinal length, complex formations, and a large number of bolt connections between the longitudinal pipe rings, resulting in large discontinuity in the stiffness of the tunnel structure. Therefore, the existing seismic calculation theory for long underground structures cannot fully reflect the Overall stiffness and deformation characteristics of the ring

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