Three-dimensional numerical modelling of site effects in the Palatine Hill, Roman Forum, and Coliseum archaeological area

In this work we analyzed the three-dimensional seismic site response of the Central Archaeological Area of Rome, which includes the Palatine Hill, Roman Forum, and Coliseum area. The study area is characterized by complex site conditions (stratigraphy, dynamic properties, surficial and buried morphology, etc). Detailed three-dimensional large-scale model was built in order to evaluate site response using dynamic numerical modelling approach. The explicit finite&#8208;difference code FLAC3D (ITASCA Consulting group Inc., 2017) was used for numerical simulations.The area of Rome is affected by earthquakes from different seismogenic districts: (1) the central Apennine mountain chain, located about 90&#8211;130km east of Rome (M = 6.7&#8211;7.0); (2) the Colli Albani volcanic area located 20km to the south of the city (M=5.5); and (3) the Rome area itself characterized by rare, shallow, low-magnitude events (M < 5). Both artificial and natural accelerograms were then simulated to be compatible with the reference spectra associated to the three earthquake scenarios.This study highlights the role of local geological and geotechnical conditions producing amplification of seismic ground motion. The analyses show maximum amplification factors, defined in terms of Housner Intensity ratio for three periods range (0.1-0.5; 0.5-1.0 and 1.0-2.0), as high as 2.2&#8211;2.4 over the period range of 0.1&#8211;1.0 s. Such values can be significantly relevant for the monumental and archaeological heritage of this area, as many are highly vulnerable due to their great age. Physical phenomena controlling site response are discussed on the basis of buried and surficial morphology and lithostratigraphic conditions.&#160; Finally, microzonation maps are produced in order to ascertain the seismic hazard of the examined area and, consequently, to assess possible parameters for seismic retrofitting of the monuments.

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Stability Improvement Method for Embankment Dam with Respect to Conduit Cracks

Applied Sciences ◽

10.3390/app12020567 ◽

2022 ◽

Vol 12 (2) ◽

pp. 567

Author(s):

Young-Hak Lee ◽

Jung-Hyun Ryu ◽

Joon Heo ◽

Jae-Woong Shim ◽

Dal-Won Lee

Keyword(s):

Large Scale ◽

Pore Water Pressure ◽

Water Pressure ◽

Three Dimensional ◽

Internal Erosion ◽

Scale Model ◽

Seepage Analysis ◽

Large Scale Model ◽

Proposed Model ◽

Improvement Method

In recent years, as the number of reservoir embankments constructed has increased, embankment failures due to cracks in aging conduits have also increased. In this study, a crack in a conduit was modeled based on the current conduit design model, and the risk of internal erosion was analyzed using a large-scale model test and three-dimensional deformation–seepage analysis. The results show that when cracks existed in the conduit, soil erosion and cavitation occurred near the crack area, which made the conduit extremely vulnerable to internal erosion. Herein, a model is proposed that can reduce internal erosion by applying a layer of sand and geotextiles on the upper part of the conduit located close to the downstream slope. In the proposed model, only partial erosion occurred inside the conduit, and no cavitation appeared near the crack in the conduit. The results suggest that internal erosion can be suppressed when the water pressure acting intensively on the crack in the conduit is dispersed by the drainage layer. To validate these results, the pore water pressure, seepage line, and hydraulic gradient were investigated to confirm the erosion phenomenon and reinforcement effect.

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Investigation of Wedge Probe Wall Proximity Effects: Part 2—Numerical and Analytical Modeling

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2817027 ◽

1997 ◽

Vol 119 (3) ◽

pp. 605-611 ◽

Cited By ~ 2

Author(s):

P. D. Smout ◽

P. C. Ivey

Keyword(s):

Large Scale ◽

Three Dimensional ◽

Outer Wall ◽

Aerodynamic Characteristics ◽

Proximity Effects ◽

Wake Flow ◽

Scale Model ◽

Flow Structures ◽

Flow Features ◽

Wall Proximity

An experimental study of wedge probe wall proximity effects is described in Part 1 of this paper. Actual size and large-scale model probes were tested to understand the mechanisms responsible for this effect, by which free-stream pressure near the outer wall of a turbomachine may be overindicated by up to 20 percent dynamic head. CFD calculations of the flow over two-dimensional wedge shapes and a three-dimensional wedge probe were made in support of the experiments, and are reported in this paper. Key flow structures in the probe wake were identified that control the pressures indicated by the probe in a given environment. It is shown that probe aerodynamic characteristics will change if the wake flow structures are modified, for example by traversing close to the wall, or by calibrating the probe in an open jet rather than in a closed section wind tunnel. A simple analytical model of the probe local flows was derived from the CFD results. It is shown by comparison with experiment that this model captures the dominant flow features.

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Studies on Three-Dimensional (3D) Modeling of UAV Oblique Imagery with the Aid of Loop-Shooting

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi7090356 ◽

2018 ◽

Vol 7 (9) ◽

pp. 356 ◽

Cited By ~ 1

Author(s):

Jia Li ◽

Yongxiang Yao ◽

Ping Duan ◽

Yun Chen ◽

Shuang Li ◽

...

Keyword(s):

3D Modeling ◽

Large Scale ◽

3D Model ◽

Three Dimensional ◽

Scale Model ◽

Scene Modeling ◽

Standard Scale ◽

Large Scale Model ◽

City Construction ◽

Key Steps

Oblique imagery obtained from an Unmanned Aerial Vehicle (UAV) has been widely applied to large-scale three-dimensional (3D) reconstruction; however, the problems of partially missing model details caused by such factors as occlusion, distortion, and airflow, are still not well resolved. In this paper, a loop-shooting-aided technology is used to solve the problem of details loss in the 3D model. The use of loop-shooting technology can effectively compensate for losses caused by occlusion, distortion, or airflow during UAV flight and enhance the 3D model details in large scene- modeling applications. Applying this technology involves two key steps. First, based on the 3D modeling construction process, the missing details of the modeling scene are found. Second, using loop-shooting image sets as the data source, incremental iterative fitting based on aerotriangulation theory is used to compensate for the missing details in the 3D model. The experimental data used in this paper were collected from Yunnan Normal University, Chenggong District, Kunming City, Yunnan Province, China. The experiments demonstrate that loop-shooting significantly improves the aerotriangulation accuracy and effectively compensates for defects during 3D large-scale model reconstruction. In standard-scale distance tests, the average relative accuracy of our modeling algorithm reached 99.87% and achieved good results. Therefore, this technique not only optimizes the model accuracy and ensures model integrity, but also simplifies the process of refining the 3D model. This study can be useful as a reference and as scientific guidance in large-scale stereo measurements, cultural heritage protection, and smart city construction.

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Investigation of Wedge Probe Wall Proximity Effects: Part 2 — Numerical and Analytical Modelling

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education; General ◽

10.1115/96-gt-147 ◽

1996 ◽

Author(s):

Peter D. Smout ◽

Paul C. Ivey

Keyword(s):

Large Scale ◽

Three Dimensional ◽

Outer Wall ◽

Aerodynamic Characteristics ◽

Proximity Effects ◽

Wake Flow ◽

Scale Model ◽

Flow Structures ◽

Flow Features ◽

Wall Proximity

An experimental study of wedge probe wall proximity effects is described in Part 1 of this paper. Actual size and large scale model probes were tested to understand the mechanisms responsible for this effect, by which free stream pressure near the outer wall of a turbomachine may be over indicated by upto 20% dynamic head. CFD calculations of the flow over two-dimensional wedge shapes and a three-dimensional wedge probe were made in support of the experiments, and are reported in this paper. Key flow structures in the probe wake were identified which control the pressures indicated by the probe in a given environment. It is shown that probe aerodynamic characteristics will change if the wake flow structures are modified, for example by traversing close to the wall, or by calibrating the probe in an open jet rather than in a closed section wind tunnel. A simple analytical model of the probe local flows was derived from the CFD results. It is shown by comparison with experiment that this model captures the dominant flow features.

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NUMERICAL SIMULATION OF THREE-DIMENSIONAL FLOW AROUND HARBOR DUE TO TSUNAMI USING FAVOR METHOD AND WENO SCHEME

Coastal Engineering Proceedings ◽

10.9753/icce.v36.papers.71 ◽

2018 ◽

pp. 71

Author(s):

Yuki Kajikawa ◽

Masamitsu Kuroiwa ◽

Naohiro Otani

Keyword(s):

Flow Field ◽

Large Scale ◽

Three Dimensional ◽

Weno Scheme ◽

Scale Model ◽

Governing Equations ◽

3D Flow ◽

Complex Boundaries ◽

Cartesian Coordinate ◽

Fifth Order

In this paper, a three-dimensional (3D) tsunami flow model was proposed in order to predict a 3D flow field around a harbor accurately when tsunami strikes. In the proposed numerical model, the Cartesian coordinate system was adopted, and the Fractional Area/Volume Obstacle Representation (FAVOR) method, which has the ability to impose boundary conditions smoothly at complex boundaries, was introduced into the governing equations in consideration of applying the estimation to actual harbors with complex shape in the future. Moreover, the fifth-order Weighted Essentially Non- Oscillatory (WENO) scheme, which is a technique for achieving high accuracy even if the calculation mesh is coarse, was applied to discretization of the convection terms of the governing equations. In order to verify the validity of the model, it was applied to a large-scale laboratory experiment with a scale model of harbor. Comparisons between the simulated and experimental results showed that the model was able to reproduce the time variation of the flow field with sufficient accuracy. Moreover, the simulated results showed that a complex 3D flow field with some vertical vortex flows was generated around a harbor when tsunami struck.

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Numerical modelling of site effects in the Palatine Hill, Roman Forum, and Coliseum Archaeological Area

Bulletin of Earthquake Engineering ◽

10.1007/s10518-013-9436-5 ◽

2013 ◽

Vol 12 (3) ◽

pp. 1383-1403 ◽

Cited By ~ 12

Author(s):

Alessandro Pagliaroli ◽

Bruno Quadrio ◽

Giuseppe Lanzo ◽

Tito Sanò

Keyword(s):

Numerical Modelling ◽

Site Effects ◽

Palatine Hill ◽

Roman Forum

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A Large-Scale Model Developed for Predicting the Corroding Conditions of a Carrier Pipe in a Casing

Volume 2: Pipeline Integrity Management ◽

10.1115/ipc2012-90475 ◽

2012 ◽

Author(s):

Fengmei Song ◽

Andrew Nordquist

Keyword(s):

Large Scale ◽

Three Dimensional ◽

Scale Model ◽

Coating Quality ◽

Metallic Contact ◽

Internal Surfaces ◽

Voltage Variation ◽

Large Scale Model ◽

Pipe Segment ◽

Industry Needs

The corroding conditions of a cased carrier pipe segment are difficult to measure in the field. It is hard to know whether or how well the cased pipe segment is cathodically protected. The pipeline industry needs a tool that can predict the in-situ corrosion potential of the carrier pipe in the casing annulus in order to determine the level of cathodic protection (CP). This work reports on a large-scale, three-dimensional computer model developed to make such a prediction. The casing wall may be treated as bare or coated on both or either of the external and internal surfaces. The carrier pipe is coated, and the coating quality inside the annulus may or may not be the same as the outside of the casing segment. The casing annulus is full of electrolytes. The model is used to investigate the effect of several factors on the level of CP imposed on the carrier pipe in the annulus, including the coating quality on the carrier pipe, the casing wall native potentials (both external and internal), the presence of a coating on a casing wall surface, and a metallic contact (between the casing and the carrier pipe) with the contact resistance being a variable. The effect of the voltage variation inside the pipe metal wall is also investigated.

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Reconciling Juno and past mission datasets to improve large-scale models of radiation-belt electron and radio emission distributions at Jupiter

10.5194/egusphere-egu21-6294 ◽

2021 ◽

Author(s):

Daniel Santos-Costa ◽

Frederic Allegrini ◽

Rob Wilson ◽

Peter Kollmann ◽

George Clark ◽

...

Keyword(s):

Radio Emission ◽

Large Scale ◽

Three Dimensional ◽

Planck Equation ◽

Radiation Belts ◽

Scale Model ◽

Data Sets ◽

Electron Radiation ◽

Large Scale Model ◽

Electron Distributions

We present our latest model of electron radiation belts developed for a large region of Jupiter's magnetosphere (1-50 Rj). For the region inward of Io, electron distributions are computed from a computational code that&#160;solves the governing three-dimensional Fokker-Planck equation. This physics-based model accounts for different mechanisms to discuss the energy and spatial distributions of electrons for L values between 1 and 5. The model for the innermost magnetospheric region is expanded to the middle magnetosphere using an empirical approach. In this paper, we first show how our large-scale model of Jupiter's electron radiation belts agrees with data sets from past missions (Pioneer 10 and 11 GTT, Galileo EPD and EPI measurements). We then focus on our effort to combine Juno (JEDI, JADE Electron Ambient Background Counts) and Galileo EPD (> 1.5, 11.5 MeV) datasets to improve our model for both the region beyond Io and the inner edge of the Jovian electron radiation belts. Finally, simulations of Jupiter's synchrotron emission are presented to gauge the contribution of ultra-energetic electrons trapped beyond L ~ 3 at different latitudes to radio emission observed by Juno MWR.

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Small-Scale Models for Testing Masonry Structures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.133-134.497 ◽

2010 ◽

Vol 133-134 ◽

pp. 497-502 ◽

Cited By ~ 2

Author(s):

Alvaro Quinonez ◽

Jennifer Zessin ◽

Aissata Nutzel ◽

John Ochsendorf

Keyword(s):

Large Scale ◽

Low Cost ◽

Three Dimensional ◽

Model Testing ◽

Scale Model ◽

Small Scale ◽

Material Strength ◽

Masonry Structures ◽

Scale Models ◽

Set Up

Experiments may be used to verify numerical and analytical results, but large-scale model testing is associated with high costs and lengthy set-up times. In contrast, small-scale model testing is inexpensive, non-invasive, and easy to replicate over several trials. This paper proposes a new method of masonry model generation using three-dimensional printing technology. Small-scale models are created as an assemblage of individual blocks representing the original structure’s geometry and stereotomy. Two model domes are tested to collapse due to outward support displacements, and experimental data from these tests is compared with analytical predictions. Results of these experiments provide a strong understanding of the mechanics of actual masonry structures and can be used to demonstrate the structural capacity of masonry structures with extensive cracking. Challenges for this work, such as imperfections in the model geometry and construction problems, are also addressed. This experimental method can provide a low-cost alternative for the collapse analysis of complex masonry structures, the safety of which depends primarily on stability rather than material strength.

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