Application of an Investigated Lump Method to the Simulation of Ground Motion For Beichuan Town During the Wenchuan Earthquake

2016 ◽  
Vol 10 (01) ◽  
pp. 1650002 ◽  
Author(s):  
Wei Zhong ◽  
Tie-Lin Liu

An investigated lump method based on the mixed mesh of triangle and quadrangle for simulating near-fault ground motion is presented by using finite-fault sources and a differential type of viscoelastic constitutive equations of the generalized zener body (GZB) with two mechanisms. One numerical test is performed to verify the validity and accuracy of the investigated lump method. The ground motion in Beichuan town during the Wenchuan earthquake is simulated, considering attenuation of real earth material and the effect of realistic topography. Numerical results of simulations demonstrated that the viscoelasticity of earth medium attenuates the PGAs noticeably and changes the frequency characteristics of the ground motion. The local topography influences greatly the PGAs in the area of Beichuan town.

Author(s):  
Arben Pitarka ◽  
Aybige Akinci ◽  
Pasquale De Gori ◽  
Mauro Buttinelli

ABSTRACT The Mw 6.5 Norcia, Italy, earthquake occurred on 30 October 2016 and caused extensive damage to buildings in the epicentral area. The earthquake was recorded by a network of strong-motion stations, including 14 stations located within a 5 km distance from the two causative faults. We used a numerical approach for generating seismic waves from two hybrid deterministic and stochastic kinematic fault rupture models propagating through a 3D Earth model derived from seismic tomography and local geology. The broadband simulations were performed in the 0–5 Hz frequency range using a physics-based deterministic approach modeling the earthquake rupture and elastic wave propagation. We used SW4, a finite-difference code that uses a conforming curvilinear mesh, designed to model surface topography with high numerical accuracy. The simulations reproduce the amplitude and duration of observed near-fault ground motions. Our results also suggest that due to the local fault-slip pattern and upward rupture directivity, the spatial pattern of the horizontal near-fault ground motion generated during the earthquake was complex and characterized by several local minima and maxima. Some of these local ground-motion maxima in the near-fault region were not observed because of the sparse station coverage. The simulated peak ground velocity (PGV) is higher than both the recorded PGV and predicted PGV based on empirical models for several areas located above the fault planes. Ground motions calculated with and without surface topography indicate that, on average, the local topography amplifies the ground-motion velocity by 30%. There is correlation between the PGV and local topography, with the PGV being higher at hilltops. In contrast, spatial variations of simulated PGA do not correlate with the surface topography. Simulated ground motions are important for seismic hazard and engineering assessments for areas that lack seismic station coverage and historical recordings from large damaging earthquakes.


MethodsX ◽  
2020 ◽  
Vol 7 ◽  
pp. 100725
Author(s):  
Zhen Liu ◽  
Shibo Zhang ◽  
Zhe Zhang

2020 ◽  
Vol 139 ◽  
pp. 106289
Author(s):  
Lizhong Jiang ◽  
Jian Yu ◽  
Wangbao Zhou ◽  
Wangji Yan ◽  
Zhipeng Lai ◽  
...  

2016 ◽  
Vol 60 (2) ◽  
pp. 205-215 ◽  
Author(s):  
Prabhat Kumar ◽  
◽  
Ashwani Kumar ◽  
Ashok Deota Pandey ◽  
◽  
...  

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