Near-field-intensity ground motion estimation method based on finite element model

Abstract

The invention relates to a near-field-intensity ground motion estimation method based on a finite element model, and the method comprises the steps: constructing a two-dimensional fault fracture surface finite element model, initializing a tectonic stress field in a static finite element model, and triggering a seismic event; setting an artificial boundary with an equivalent boundary unit, extracting seismic oscillation parameters, and realizing bed rock seismic oscillation simulation; and in the static finite element model, obtaining an initial stress state under a fault surface boundary fracture state when a seismic event occurs, and transferring the obtained initial stress state in the static finite element model to the dynamic finite element model for nonlinear analysis to obtain a seismic oscillation acceleration time-history estimated value. According to the method, a two-dimensional finite element model is used for replacing a traditional three-dimensional Green function model,so that the operand is reduced, and meanwhile, the operation time is shortened; and meanwhile, a rapid estimation result of strong ground motion of the earthquake event is provided, and important guiding significance is achieved for command and decision making of earthquake emergency rescue after an earthquake.

Description

technical field [0001] The invention belongs to the field of earthquake engineering and geotechnical engineering, and in particular relates to a method for estimating near-field strong ground motion based on a finite element model, which can provide earthquake parameters required for engineering and earthquake rescue. Background technique [0002] The existing methods for estimating strong earthquake ground motion are mainly based on theoretical and empirical Green's function methods. This type of method is based on the elastodynamic representation theorem, and the displacement of a certain point on the surface caused by the slip dislocation on the entire fault plane can be expressed as a slip time function on the fault (source effect) and as a representation of the impulse response of the propagation medium (propagation path Effect) of the space-time convolution of the Green's function. This type of method can clearly show the influence of source characteristics on the cha...

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Problems solved by technology

Therefore, when the Green's function method is directly applied to the engineering practice of disaster prevention and mitigation, there are difficulties in obtaining three-dimensional velocity structure information and complex parameter settings.

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