Numerical modeling of seismically-induced slope displacements: a comparison between 2D and 3D finite difference models and Newmark-Displacements

2020 ◽  
Author(s):  
Gisela Domej ◽  
Céline Bourdeau
Keyword(s):  
Finite Difference ◽  
Cross Section ◽  
3D Model ◽  
3D Models ◽  
Southern Spain ◽  
Longitudinal Cross Section ◽  
Landslide Body ◽  
Mesh Grid ◽  
2D And 3D ◽  
2D Model

<p>The majority of numerical landslide models are designed in 2D. In particular, models based on finite difference methods (FDM) are time-consuming and – as a result – in most cases also cost-intensive. 3D models, therefore, increase the processing time significantly. Another contributing factor to long processing times in the context of modeling of seismically-induced displacements is the fact that mesh grid increments must be small due to the necessity of correct wave propagation through the material. The larger the frequency range of the applied seismic signal should be, the smaller has to be the mesh grid increment. 3D models are, however, considered as more realistic.</p><p>In this work, we present a comprehensive study on numerical 2D and 3D models of the Diezma Landslide, Southern Spain. The Landslide is represented in its shape as it appeared at the time of the main rupture on 18<sup>th</sup> of March in four model layouts: (1) a simplified model in 3D that outlines the landslide body with planar triangular tiles, (2) a longitudinal cross section through this simplified 3D model representing the simplified 2D model, (3) a smooth model in 3D that envelops the landslide body according to the main topographic features, and (4) a longitudinal cross section through this smooth 3D model representing the smooth 2D model.</p><p>On both the simplified and the smooth 2D models, a series of 11 seismic scenarios was applied as SV-waves assuming a source sufficiently far for vertical incidence at the model bottoms in order to produce horizontal shear inside the landslide body with respect to the underlying bedrock. All 11 signals are characterized by different frequency contents, Arias Intensities from 0.1 to 1 m/s, moment magnitudes from 5.0 to 7.0 and peak ground accelerations from 0.8 to 1.2 m/s², and therefore correspond to scenarios that represent the local seismicity in Southern Spain.<br>Because of time-related limitations, only four of these signals were respectively applied to the simplified and smooth 3D model. Newmark-Displacements were calculated using all 11 signals with the classic Newmark-Method that approximates the landslide body in 2D by a rigid block on an inclined plane, and with Newmark’s Empirical Law as spatial information covering the landslide area across the slope in regular intervals.</p><p>We present a systematic comparison of all models and obtained displacements, showing that the Newmark-Methods deliver very similar results to the maximum displacements obtained by FDM. Moreover, we discuss on a particular example that – although seeming more accurate in the layout – smooth models lead not necessarily to realistic results.</p>

scholarly journals Comparison of Induced Deflection and Forces in Piles Adjacent to Tunnelling and Deep Excavation in 2D and 3D Problems

2018 ◽  
Vol 203 ◽  
pp. 04011
Author(s):  
Ong Yin Hoe ◽  
Hisham Mohamad
Keyword(s):  
Bending Moment ◽  
Pile Group ◽  
3D Models ◽  
Deep Excavation ◽  
Pile Groups ◽  
Out Of Plane ◽  
National University ◽  
Plane Direction ◽  
2D And 3D ◽  
2D Model

There is a trend in Malaysia and Singapore, engineers tend to model the effect of TBM tunneling or deep excavation to the adjacent piles in 2D model. In the 2D model, the pile is modelled using embedded row pile element which is a 1-D element. The user is allowed to input the pile spacing in out-of-plane direction. This gives an impression to engineers the embedded pile row element is able to model the pile which virtually is a 3D problem. It is reported by Sluis (2014) that the application of embedded pile row element is limited to 8D of pile length. It is also reported that the 2D model overestimates the axial load in pile and the shear force and bending moment at pile top and it is not realistic in comparison to 3D model. In this paper, the centrifuge results of single pile and 6-pile group - tunneling problem carried out in NUS (National University of Singapore) are back-analysed with Midas GTS 3D and a 2D program. In a separate case study, pile groups adjacent to a deep excavation is modelled by 3D and 2D program. This paper compares the deflection and forces in piles in 2D and 3D models.

scholarly journals Semi-CNN Architecture for Effective Spatio-Temporal Learning in Action Recognition

2020 ◽  
Vol 10 (2) ◽  
pp. 557 ◽  
Author(s):  
Mei Chee Leong ◽  
Dilip K. Prasad ◽  
Yong Tsui Lee ◽  
Feng Lin
Keyword(s):  
Neural Networks ◽  
Action Recognition ◽  
3D Model ◽  
3D Models ◽  
Temporal Features ◽  
Temporal Encoding ◽  
Spatio Temporal ◽  
Efficient Learning ◽  
2D And 3D ◽  
Temporal Learning

This paper introduces a fusion convolutional architecture for efficient learning of spatio-temporal features in video action recognition. Unlike 2D convolutional neural networks (CNNs), 3D CNNs can be applied directly on consecutive frames to extract spatio-temporal features. The aim of this work is to fuse the convolution layers from 2D and 3D CNNs to allow temporal encoding with fewer parameters than 3D CNNs. We adopt transfer learning from pre-trained 2D CNNs for spatial extraction, followed by temporal encoding, before connecting to 3D convolution layers at the top of the architecture. We construct our fusion architecture, semi-CNN, based on three popular models: VGG-16, ResNets and DenseNets, and compare the performance with their corresponding 3D models. Our empirical results evaluated on the action recognition dataset UCF-101 demonstrate that our fusion of 1D, 2D and 3D convolutions outperforms its 3D model of the same depth, with fewer parameters and reduces overfitting. Our semi-CNN architecture achieved an average of 16–30% boost in the top-1 accuracy when evaluated on an input video of 16 frames.

scholarly journals Numerical Analysis of Stratified and Slug Flows

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Saliha Nouri ◽  
Zouhaier Hafsia ◽  
Salah Mahmoud Boulaaras ◽  
Ali Allahem ◽  
Salem Alkhalaf ◽  
...  
Keyword(s):  
Axial Velocity ◽  
Volume Fraction ◽  
Stratified Flow ◽  
3D Models ◽  
Water Volume ◽  
Volume Distribution ◽  
Two Phase ◽  
Slug Flows ◽  
2D And 3D ◽  
2D Model

The main purpose of this study is to compare two-dimensional (2D) and three-dimensional (3D) two-phase models for both stratified and slug flows. These two flow regimes interest mainly the petroleum and chemical industries. The volume of fluid (VOF) approach is used to predict the interface between the two-phase flows. The stratified turbulent flow corresponds to the oil-water phases through a cylindrical pipe. To simulate the turbulent stratified flow, the k − ω turbulence model is used. The slug laminar flow concerns the kerosene-water phases through a rectangular microchannel. The simulated results are validated using the previous experimental results available in the literature. For the stratified flow, the axial velocity and the water volume fraction profiles obtained by 2D and 3D models approximate the measurement profiles at the same test section. Also, the T-junction in a 2D model affects only the inlet vicinity. For downstream, the 2D and 3D models lead to the same axial velocity and water volume distribution. For the slug flow, the simulated results show that the 3D model predicts the thin film wall contrary to the 2D model. Moreover, the 2D model underestimates the slug length.

Assessment of the local mechano-electrochemical effect on pipeline defects by 2D and 3D finite element models

CORROSION ◽  
10.5006/3774 ◽  
2021 ◽  
Author(s):  
Zhuwu Zhang ◽  
Jiuhong Zhang ◽  
Jinchang Wang ◽  
Y. Frank Cheng
Keyword(s):  
Finite Element ◽  
3D Model ◽  
Local Stress ◽  
Anodic Current Density ◽  
Defect Center ◽  
Zone Length ◽  
3D Finite Element ◽  
2D And 3D ◽  
2D Model ◽  
Anodic Zone

Local corrosion at a defect on a pipeline was assessed using both 2-dimensional (2D) and 3D finite element (FE) models under mechano-electrochemical (M-E) interaction. While the M-E interaction increases corrosion activity at the defect, the assessment of M-E interaction would have different results using 2D and 3D models. Compared with the 3D model, the 2D model produces a greater local stress, a higher local plastic strain, a more negative corrosion potential and a higher anodic current density at the defect, and thus, a lower threshold internal pressure causing local yielding. The 3D model is more conservative for corrosion rate prediction of corroded pipelines. A new concept, rAZ (the ratio of the anodic zone length to defect length in the 2D model, or the ratio of the anodic zone area to the defect area in the 3D model), is proposed to define growth mode of the corrosion defect. There is a smaller rAZ produced in 2D model. At specific internal pressures, the 2D model predicts an ellipsoidal defect center area experiencing accelerated corrosion and potentially resulting in pipeline leaking.

scholarly journals A comparison of a two-dimensional depth averaged flow model and a three-dimensional RANS model for predicting tsunami inundation and fluid forces

2018 ◽  
Author(s):  
Xinsheng Qin ◽  
Michael Motley ◽  
Randall LeVeque ◽  
Frank Gonzalez ◽  
Kaspar Mueller
Keyword(s):  
Built Environment ◽  
3D Model ◽  
Computational Cost ◽  
Three Dimensional ◽  
Vertical Direction ◽  
3D Models ◽  
Tsunami Inundation ◽  
Model Based ◽  
Fine Mesh ◽  
2D Model

Abstract. The numerical modeling of tsunami inundation that incorporates the built environment of coastal communities is challenging for both depth-integrated 2D and 3D models, not only in modeling the flow, but also in predicting forces on coastal structures. For depth-integrated 2D models, inundation and flooding in this region can be very complex with variation in the vertical direction caused by wave breaking on shore and interactions with the built environment and the model may not be able to produce enough detail. For 3D models, a very fine mesh is required to properly capture the physics, dramatically increasing the computational cost and rendering impractical the modeling of some problems. In this paper, comparisons are made between GeoClaw, a depth-integrated 2D model based on the nonlinear shallow water equations (NSWE), and OpenFOAM, a 3D model based on Reynolds Averaged Navier-Stokes (RANS) equation for tsunami inundation modeling. The two models were first validated against existing experimental data of a bore impinging onto a single square column. Then they were used to simulate tsunami inundation of a physical model of Seaside, Oregon. The resulting flow parameters from the models are compared and discussed, and these results are used to extrapolate tsunami-induced force predictions. It was found that the 2D model did not accurately capture the important details of the flow near initial impact due to the transiency and large vertical variation of the flow. Tuning the drag coefficient of the 2D model worked well to predict tsunami forces on structures in simple cases but this approach was not always reliable in complicated cases. The 3D model was able to capture transient characteristic of the flow, but at a much higher computational cost; it was found this cost can be alleviated by subdividing the region into reasonably sized subdomains without loss of accuracy in critical regions.

Slope Stability Comparatively Analyzed with 2D and 3D FEM

2012 ◽  
Vol 220-223 ◽  
pp. 2908-2911
Author(s):  
Jie Qun Liu ◽  
Jin Long Liu
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
3D Model ◽  
Model Analysis ◽  
Stability Factor ◽  
Surface Load ◽  
3D Fem ◽  
The Stability ◽  
2D And 3D ◽  
2D Model

A typical slope has been comparatively analyzed with 2D and 3D FEM, it is showed that the length of surface load at top surface of slope shorted, the stability factor of slope of 3D model increased, which is far more than that of 2D model. In a certain degree, the safety factor got by 3D model is bigger than that of 2D model, so the safety factor of slope is underestimated by 2D model analysis sometimes.

scholarly journals A Study on 3D Model Construction by Controlling Unmanned Aerial Vehicle of Camera Angle

2021 ◽  
Vol 21 (2) ◽  
pp. 149-157
Author(s):  
Youngseok Song ◽  
Hyeong Jun Lee ◽  
Byung Sik Kim ◽  
Moojong Park
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Point Cloud ◽  
3D Model ◽  
3D Models ◽  
Aerial Photographs ◽  
Camera Angle ◽  
Aerial Vehicle ◽  
2D And 3D ◽  
Quantitative Impact ◽  
Orthophoto Images

In this study, the camera angle of a UAV (Unmanned Aerial Vehicle) was adjusted to take aerial photographs, and 2D and 3D models were constructed to evaluate the quantitative impact. The study area was Waryong Bridge, located in Dalseong-gun, Daegu Metropolitan City. The camera angles of the UAV were 90°, 75°, and 60°; DSM, orthophoto, and the 3D model were analyzed. As a result of the analysis of DSM and orthophoto, images were 1.05 times in 75° and 1.10 times in 60° compared to 90°, and matching was 1.09 times in 75° and 1.60 times in 60° compared to 90°. The point cloud for building 3D models increased analysis points to 1.17 times for 75° and 1.47 times for 60° compared to 90°. However, the area of an orthophoto of 1 pixel increased by 1.10 times for 75° and 1.34 times for 60° compared to 90°, resulting in a decrease in resolution. As the camera angle of the UAV decreases, the overlapping ratio of aerial photographs increases and the structure of wide areas can be implemented. However, since a large difference occurs in the precision of the 3D model, a shooting plan according to the purpose should be established.

scholarly journals The Impact of Dimensionality on Barotropic Processes during KWAJEX

2017 ◽  
Vol 74 (8) ◽  
pp. 2675-2688 ◽  
Author(s):  
Huiyan Xu ◽  
Xiaofan Li
Keyword(s):  
Kinetic Energy ◽  
3D Model ◽  
Model Simulation ◽  
Vertical Transport ◽  
Model Simulations ◽  
The Mean ◽  
Horizontal Momentum ◽  
2D And 3D ◽  
The Impact ◽  
2D Model

Abstract In this study, the 2D and 3D cloud-resolving model simulations of the Tropical Rainfall Measuring Mission (TRMM) Kwajalein Experiment (KWAJEX) are compared to study the impact of dimensionality on barotropic processes during tropical convective development. Barotropic conversion of perturbation kinetic energy is associated with vertical transport of horizontal momentum under vertical shear of background horizontal winds. The similarities in both 2D and 3D model simulations show that 1) vertical wind shear is a necessary condition for barotropic conversion, but it does not control the barotropic conversion; 2) the evolution of barotropic conversion is related to that of the vertical transport of horizontal momentum; and 3) the tendency of vertical transport of horizontal momentum is mainly determined by the covariance between horizontal wind and the cloud hydrometeor component of buoyancy. The differences between the 2D and 3D model simulations reveal that 1) the barotropic conversion has shorter time scales and a larger contribution in the 2D model simulation than in the 3D model simulation and 2) kinetic energy is generally converted from the mean circulations to perturbation circulations in the 3D model simulation. In contrast, more kinetic energy is transferred from perturbation circulations to the mean circulations in the 2D model simulation. The same large-scale vertical velocity may account for the similarities, whereas the inclusion of meridional winds in the 3D model simulation may be responsible for the differences in barotropic conversion between the 2D and 3D model simulations.

scholarly journals Potassium Ascorbate with Ribose: Promising Therapeutic Approach for Melanoma Treatment

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Carlotta Cavicchio ◽  
Mascia Benedusi ◽  
Erika Pambianchi ◽  
Alessandra Pecorelli ◽  
Franco Cervellati ◽  
...  
Keyword(s):  
Connexin 43 ◽  
Early Stage ◽  
3D Models ◽  
Definitive Treatment ◽  
Novel Treatments ◽  
Promising Therapeutic Approach ◽  
Current Therapies ◽  
Melanoma Treatment ◽  
2D And 3D ◽  
2D Model

While surgery is the definitive treatment for early-stage melanoma, the current therapies against advanced melanoma do not yet provide an effective, long-lasting control of the lesions and a satisfactory impact on patient survival. Thus, research is also focused on novel treatments that could potentiate the current therapies. In the present study, we evaluated the effect of potassium ascorbate with ribose (PAR) treatment on the human melanoma cell line, A375, in 2D and 3D models. In the 2D model, in line with the current literature, the pharmacological treatment with PAR decreased cell proliferation and viability. In addition, an increase in Connexin 43 mRNA and protein was observed. This novel finding was confirmed in PAR-treated melanoma cells cultured in 3D, where an increase in functional gap junctions and a higher spheroid compactness were observed. Moreover, in the 3D model, a remarkable decrease in the size and volume of spheroids was observed, further supporting the treatment efficacy observed in the 2D model. In conclusion, our results suggest that PAR could be used as a safe adjuvant approach in support to conventional therapies for the treatment of melanoma.

An Attempt to Image Um El-Adam Cavity Structure in the Karst Terrain at Hit Area, Western Iraq

2020 ◽  
Vol 54 (1A) ◽  
pp. 44-54
Author(s):  
Ali Abed
Keyword(s):  
3D Model ◽  
3D Models ◽  
Electrode Spacing ◽  
Karst Terrain ◽  
Resistivity Imaging ◽  
Cavity Structure ◽  
2D Resistivity Imaging ◽  
2D And 3D ◽  
2D Resistivity

Um El-Adam cavity is one of the well-known cavities inside gypsum rocks in the Hit region, western Iraq, where this was chosen as a case study to evaluate 3D resistivity imaging technique detection and imaging of this type of cavity in complicated lithology. 3D view fulfilled by collating four 2D resistivity-imaging lines. The 2D resistivity imaging survey was carried out by Dipole-Dipole array with (n) factor and electrode spacing (a) of 6 and 2m, respectively. Both conventional inversion methods obtained the 2D and 3D models: standard least-squares and robust constrain options. The two options were able to define clearly the cave, but the second was more accurate, the dimensions of the cave in the inverse model closer to the actual dimensions. Horizontal slices displayed the final 3D model to reveal a 3D resistivity distribution with depth. The effect of Um El-Adam cavity appears after 1.5 m on the model slices, which is represented by increasing resistivity contrast compared to surrounding sediments. At the seventh and eighth slices, it was found that the size of the cavity exceeded compared with the actual dimensions. The results of this study indicated the high potential of this method for the detection and delineation of subterranean caves.

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