• Geomechanics and Engineering
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• v.17 no.4
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• pp.317-322
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• 2019

This paper presents the results of parametric analyses to compute the axial capacity of a suction pile using 2D and 3D finite element approaches. The study is intended to simplify the process of analyzing suction piles from 3D to 2D model. The research focuses on obtaining the coefficient to be applied into the 2D model in order to obtain results that are as close as possible to the 3D model. Two 2D models were used in the analysis, namely the plane strain and axisymmetric models. The analyses were performed using two actual offshore soil data of the North and West Java Indonesia. The study reveals that the simplification of model through 2D Finite Element is achievable by applying the appropriate coefficient to the stiffness parameters. The results show that the simplified model of the 2D FEA provides more conservative results (with the difference between 2% to 7%) than the 3D FEA.

• Journal of KIBIM
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• v.7 no.2
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• pp.8-15
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• 2017

Building Information modeling is playing an important role in transforming the construction industry. It helped the industry with better visualization, minimum design errors, and excellent planning of the construction activities. Time and cost saving can be effectively achieved by using BIM for any construction project. It improves information exchange between all the project stakeholders. However, the development of earthwork 3D BIM is still underway and has not been fully implemented yet. This paper presents the study of a complete process for Earthwork BIM design using Autodesk Civil 3D. A real site road construction project is used as a case study to explain the process of earthwork modeling, starting from laser scanning to 3D model. Quantity take off calculation is very important part of any road construction project so during this study earthwork volume from two 3D earthwork model is calculated. The results obtained through this study will be the basis for future work which has been concluded in this paper.

• Smart Structures and Systems
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• v.30 no.5
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• pp.501-511
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• 2022

Three-dimensional (3D) models have become crucial for improving civil infrastructure analysis, and they can be used for various purposes such as damage detection, risk estimation, resolving potential safety issues, alarm detection, and structural health monitoring. 3D point cloud data is used not only to make visual models but also to analyze the states of structures and to monitor them using semantic data. This study proposes automating the generation of high-quality 3D point cloud data and removing noise using deep learning algorithms. In this study, large-format aerial images of civilian infrastructure, such as cut slopes and dams, which were captured by drones, were used to develop a workflow for automatically generating a 3D point cloud model. Through image cropping, downscaling/upscaling, semantic segmentation, generation of segmentation masks, and implementation of region extraction algorithms, the generation of the point cloud was automated. Compared with the method wherein the point cloud model is generated from raw images, our method could effectively improve the quality of the model, remove noise, and reduce the processing time. The results showed that the size of the 3D point cloud model created using the proposed method was significantly reduced; the number of points was reduced by 20-50%, and distant points were recognized as noise. This method can be applied to the automatic generation of high-quality 3D point cloud models of civil infrastructures using aerial imagery.

• Earthquakes and Structures
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• v.22 no.5
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• pp.447-460
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• 2022

In this article, wave propagation in functional gradation plates (FG) resting on an elastic foundation with two parameters is studied using a new quasi-three-dimensional (3D) higher shear deformation theory (HSDT). The new qausi-3D HSOT has only five variables in fields displacement, which means has few numbers of unknowns compared with others quasi-3D. This higher shear deformation theory (HSDT) includes shear deformation and effect stretching with satisfying the boundary conditions of zero traction on the surfaces of the FG plate without the need for shear correction factors. The FG plates are considered to rest on the Winkler layer, which is interconnected with a Pasternak shear layer. The properties of the material graded for the plates are supposed to vary smoothly, with the power and the exponential law, in the z-direction. By based on Hamilton's principle, we derive the governing equations of FG plates resting on an elastic foundation, which are then solved analytically to obtain the dispersion relations. Numerical results are presented in the form of graphs and tables to demonstrate the effectiveness of the current quasi-3D theory and to analyze the effect of the elastic foundation on wave propagation in FG plates.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.6
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• pp.557-567
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• 2015

With the increasing demands of 3D spatial information in urban environment, the importance of point clouds generation techniques have been increased. In particular, for as-built BIM, the point clouds with the high accuracy and density is required to describe the detail information of building components. Since the terrestrial LiDAR has high performance in terms of accuracy and point density, it has been widely used for as-built 3D modelling. However, the high cost of devices is obstacle for general uses, and the image-based 3D reconstruction technique is being a new attraction as an alternative solution. This paper compares the image-based 3D reconstruction technique and the terrestrial LiDAR in point of establishing the as-built BIM of outdoor structures. The point clouds generated from the image-based 3D reconstruction technique could roughly present the 3D shape of a building, but could not precisely express detail information, such as windows, doors and a roof of building. There were 13.2~28.9 cm of RMSE between the terrestrial LiDAR scanning data and the point clouds, which generated from smartphone and DSLR camera images. In conclusion, the results demonstrate that the image-based 3D reconstruction can be used in drawing building footprint and wireframe, and the terrestrial LiDAR is suitable for detail 3D outdoor modeling.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.242-244
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• 2017

Excavation for construction is implemented in natural geographical terrain using a variety of construction equipment. Therefore, 3D excavation simulation requires integration of geographical and equipment modeling. This paper proposes a technique that integrates geographical and equipment modeling for 3D simulations of construction excavation. The geographical model uses a digital map to show ground surface changes during excavation and the equipment model shows equipment movement and placement. This combination produced a state of the art 3D simulation environment that can be used for machine guidance. An equipment operator can use the 3D excavation simulation to help construction equipment operators with decisions during excavation work and consequently improve productivity.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.5
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• pp.457-461
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• 2013

This paper proposes an image feature-based real-time RGB-D (Red-Green-Blue Depth) 3D SLAM (Simultaneous Localization and Mapping) system. RGB-D data from Kinect style sensors contain a 2D image and per-pixel depth information. 6-DOF (Degree-of-Freedom) visual odometry is obtained through the 3D-RANSAC (RANdom SAmple Consensus) algorithm with 2D image features and depth data. For speed up extraction of features, parallel computation is performed with GPU acceleration. After a feature manager detects a loop closure, a graph-based SLAM algorithm optimizes trajectory of the sensor and builds a 3D point cloud based map.

• Structural Engineering and Mechanics
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• v.78 no.4
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• pp.439-453
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• 2021

In this work, quasi three-dimensional (quasi-3D) shear deformation theory is presented for bending and dynamic analysis of functionally graded (FG) plates. The effect of varying material properties and volume fraction of the constituent on dynamic and bending behavior of the FG plate is discussed. The benefit of this model over other contributions is that a number of variables is diminished. The developed model considers nonlinear displacements through the thickness and ensures the free boundary conditions at top and bottom faces of the plate without using any shear correction factors. The basic equations that account for the effects of transverse and normal shear stresses are derived from Hamilton's principle. The analytical solutions are determined via the Navier procedure. The accuracy of the proposed formulation is proved by comparisons with the different 2D, 3D and quasi-3D solutions found in the literature.

• Proceedings of the KSRS Conference
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• v.1
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• pp.106-109
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• 2006

Over the years, many researches have been performed to create 3D digital maps. Nevertheless, it is still time-consuming and involves a high cost because a large part of 3D digital mapping is conducted manually. To compensate this limitation, we propose methodologies to represent 3D objects as 3D symbols and locate these symbols into a base map automatically. First of all, we constructed the 3D symbol library to represent 3D objects as 3D symbols. In the 3D symbol library, the attribute and geometry information are stored, which defines factors related to the types of symbols and related to the shapes respectively. These factors were used to match 3D objects and 3D symbols. For automatic mapping of 3D symbols into a base map, we used predefined parameters such as the size, the height, the rotation angle and the center of gravity of 3D objects which are extracted from Light Detection and Ranging (LIDAR) data and 2D digital maps. Finally, the 3D map in urban area was constructed and the mapping results were tested using aerial photos as reference data. Through this research, we can identify that the developed the algorithms can be used as effective techniques for 3D digital cartographic techniques

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.167-172
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• 2000

In this study, the behaviors of a cast-in-situ concrete pile embedded in the weathered rock were analysed by a 3D numerical analysis using PENTAGON 3D and the results were compared with those of the field load test. The load-settlement relation and the load transfer relationship were evaluated from the numerical analysis. As a result, the load-settlement relation at the pile top and the axial load distribution with depth were predicted reasonably. And those results were similar with those of the field load test.