scholarly journals An underground three-dimensional displacement measurement system

2018 ◽  
Vol 232 ◽  
pp. 02053
Author(s):  
Yifeng Cheng ◽  
Qing Li ◽  
Nanying Shentu ◽  
Chao Zhang
Keyword(s):  
Measurement System ◽  
Tilt Angle ◽  
Group Structure ◽  
Three Dimensional ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Displacement Sensor ◽  
Monitoring Methods ◽  
Geological Disaster ◽  
On Line

With the development of society, the damage of geological disaster to people's life and property is more serious, so the improvement of monitoring means of geological disaster is particularly urgent, there are some shortcomings in traditional monitoring methods, and it is impossible to measure the three-dimensional displacement of underground. The authors have designed an integrated three-dimensional displacement sensor to measure underground horizontal displacement and vertical displacement and tilt angle, and realize the real-time on-line monitoring of underground three-dimensional displacement visually through multi-group structure co-measurement.

scholarly journals Numerical Simulation Analysis of Slope Instability and Failure of Limestone Mine in Weibei

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Kuiming Liu ◽  
Hui Li ◽  
Shihui Pang ◽  
Meng Mi ◽  
Jianping Chen ◽  
...  
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
Simulation Analysis ◽  
Slip Surface ◽  
Three Dimensional ◽  
Stable State ◽  
Vertical Displacement ◽  
Slope Instability ◽  
Shaanxi Province ◽  
Geological Disaster

Weibei area is the largest limestone resource area in Shaanxi Province, which is an important boundary to distinguish the climate difference between the south and the north of China, and also a significant ecological safety protection barrier in the northwest of China. The complex geological environment and harsh environment make the mining area have serious geological disaster hidden danger. Based on the site engineering geological data of typical limestone quarry slope in Weibei, this paper constructs a three-dimensional geological model, uses FLAC3D software to simulate excavation, and analyzes the stress and strain law of the quarry slope. SlopeLE software was used to analyze the safety factor of slope stability and the potential slip surface before and after taking reinforcement measures. The results show the following: (1) Limestone is the main rock component of the mine, followed by mudstone. The joint and fissure are developed, the rock mass is broken, and the hidden danger of engineering geological disaster is high. (2) There is a sliding trend in both sides during excavation, and the maximum vertical displacement is 2.1 cm. (3) If the slope is reinforced according to the design scheme, the slope stability safety factor will be increased from 1.062 to 1.203 in a stable state, which greatly improves the stability of the slope and provides a guarantee for human and financial resources.

Real-time monitoring of changes in building tilt angle using double square artificial marks

2020 ◽  
pp. 1420326X2090916
Author(s):  
Gang Yang ◽  
Jianchao Wu ◽  
Qing Hu ◽  
Dongning Lei
Keyword(s):  
Tilt Angle ◽  
Three Dimensional ◽  
Digital Camera ◽  
Plumb Line ◽  
Monitoring Methods ◽  
Property A ◽  
Monitoring Method ◽  
Angle Change ◽  
Manual Methods ◽  
Single Pixel

To monitor changes in building tilt angles more accurately and efficiently and to safeguard the people's safety and property, a new tilt angle monitoring method was proposed in this paper. This method adopts double square artificial marks and a plumb line determined by MATLAB to record changes in the building tilt angle based on image processing technology. Two black square artificial marks with the size of 10 mm × 10 mm were placed near the side of the plumb line. A digital camera was adopted to collect tilt images which were saved in the computer. The tilt images were successively subjected to image greying, binarization, denoising, image segmentation and pixel calibration. Finally, the true length of a single pixel and tilt angle change value would be obtained. The experimental results showed that the accuracy of the method was 96% higher than the manual method. Compared with traditional manual methods and three-dimensional scanning monitoring methods, the advantages of this method are that the equipment used is relatively cheap, the image calculation workload is small and is suitable in dangerous working conditions. In conclusion, the proposed technique could accurately, concisely and effectively calculate the changes in building tilt angle and improve work efficiency.

Analysis of Seismic Experiment of Hexagonal Multi Bundle Model Using Core Assembly Mock-Up

2020 ◽  
Author(s):  
Akihisa Iwasaki ◽  
Shinichiro Matsubara ◽  
Hidenori Harada ◽  
Tomohiko Yamamoto
Keyword(s):  
Fast Reactor ◽  
Three Dimensional ◽  
Reactor Core ◽  
Vertical Direction ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
The Core ◽  
Vibration Behavior ◽  
Seismic Experiment ◽  
Core Elements

Abstract The fast reactor core is composed of hundreds of core elements that stand independently on the core support plate, but does not have support to constrain vertical displacement in order to avoid effects such as thermal elongation. When the earthquake occurs, the group vibration behavior is shown, including the rising of core elements in vertical direction, the collision with adjacent core elements in horizontal direction, and the fluid structure interaction. The three dimensional core group vibration analysis code (REVIAN-3D) was constructed to evaluate them. In the case of fast reactor cores in Japan, the horizontal displacement of core elements at the outermost periphery is restricted by the core former (core barrel). However, since there is no core former in fast reactors other than Japan and the boundary conditions are different from those in Japan, the vibration behavior also differs. In this study, to grasp and estimate the group vibration behavior with and without a core former under the earthquake motion, seismic experiment of hexagonal multi bundle model using core assembly mock-up was conducted [1]. These test results show that the horizontal displacements are larger and impact force between pads of core assembly mock-up is smaller without the core former. In this paper, the analysis was verified by group vibration tests with and without a core former.

scholarly journals Three-Dimensional Surface Displacement of the Eastern Beijing Plain, China, Using Ascending and Descending Sentinel-1A/B Images and Leveling Data

2021 ◽  
Vol 13 (14) ◽  
pp. 2809
Author(s):  
Shunkang Zhang ◽  
Beibei Chen ◽  
Huili Gong ◽  
Kunchao Lei ◽  
Min Shi ◽  
...  
Keyword(s):  
Compressive Strain ◽  
Three Dimensional ◽  
Estimation Method ◽  
Surface Displacement ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Vertical Surface ◽  
Groundwater Exploitation ◽  
Displacement Estimation ◽  
Beijing Plain

Surface displacement is an common environmental geological phenomenon in the Beijing Plain. Research on surface displacement in the Beijing Plain has mainly focused on vertical surface displacement, whereas the horizontal displacement has scarcely been studied. To investigate the 3-D surface displacement in the Beijing Plain, we construct a leveling-constrained multidirectional PS-InSAR 3-D surface displacement estimation method to obtain the 3-D surface displacement information. The results show that the surface displacement in the study area during 2016–2018 was mainly vertical displacement with two main northern and southern subsidence centers; the vertical displacement ranged from −150 mm/year (down) to 5 mm/year (up), and the east–west horizontal displacement ranged from 20 mm/year (east) to 22 mm/year (west). Validation results show that the 3-D surface displacement estimation results agree well with leveling data and GPS data, indicating the reliability of the 3-D surface displacement datasets. The 3-D surface displacement results show that horizontal displacement is obvious in the areas with a large vertical displacement in the eastern Beijing Plain. Additionally, the horizontal displacement is directed toward the center of vertical displacement. The compressive strain is observed close to the centers of vertical displacement, whereas tensile strain occurs far from the centers of vertical displacement. The main cause of the 3-D surface displacement in the study area is the long-term groundwater overexploitation, especially deep groundwater exploitation. The spatial and temporal extents of displacement do not exactly match the locations of the groundwater sinks in different aquifers; instead, geological structures and stratigraphic/lithological conditions may have a combined effect. Moreover, the spatial and temporal distributions of surface displacement are closely related to ground fissure activity, and both influence each other.

scholarly journals Displacement and Deformation of the First Tunnel Lining During the Second Tunnel Construction

2019 ◽  
Vol 5 (2) ◽  
pp. 332 ◽  
Author(s):  
Lin Wu ◽  
Xiedong Zhang ◽  
Zhihua Zhang ◽  
Luqing Luo ◽  
Weichen Sun
Keyword(s):  
Water Pressure ◽  
Three Dimensional ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Tunnel Lining ◽  
Scale Model ◽  
Tunnel Construction ◽  
Soil Arching ◽  
Clear Distance ◽  
Twin Tunnels

A three-dimensional twin tunnels scale model was established utilizing the discrete element method (DEM) with PFC3D. This model aims to investigate the displacement (in horizontal and vertical directions) and deformation of the first tunnel lining in four different cases which the clear distance of twin tunnels are 5, 10, 15 and 20 m during the second tunnel construction process. The numerical results indicate that the clear distance between twin tunnels and the distance between the measurement points of the first tunnel and the excavation area of the second tunnel are two most critical factors that influence the displacement and deformation of the first tunnel lining. Meanwhile, the soil arching effect, gravity, water pressure and lateral pressure also have an impact on the behavior of the first tunnel. The maximum disturbance of horizontal and vertical displacements occurred in the time points of finishing of the second tunnel. However, the horizontal displacement of the first tunnel is much more sensitive to the vertical displacement. The first tunnel turns to the right and down in direction while having an anticlockwise rotation (φ) during the process of construction of the second tunnel. In addition, the displacement and deformation of the lining of the first tunnel are critical to monitor, and the necessary precautions should be taken to decrease the risk of craze. In conclusion, the influence of the second tunnel excavation on the first tunnel lining could be neglected when their distance is more than 15 m.

Three-Dimensional Measurement System Based on Line Laser

2013 ◽  
Vol 333-335 ◽  
pp. 32-36
Author(s):  
Le Wen Yu ◽  
Da Zhang ◽  
Yuan Sheng Zhang
Keyword(s):  
Mathematical Model ◽  
Measurement System ◽  
Measurement Accuracy ◽  
Three Dimensional ◽  
Measurement Range ◽  
Laser Triangulation ◽  
Depth Information ◽  
Dimensional Measurement ◽  
Three Dimensional Measurement ◽  
On Line

This paper puts forward a three-dimensional measurement system based on line laser, describing its operating principle. Extracted the light stripes center by image processing technology, and establishing mathematical model, detecting the depth information by the method of laser triangulation, and reconstructed the three-dimensional form of object. The experimental results indicate that measurement accuracy less than ±0.03mm when the measurement range between 0mm to 10mm.

Study on Stability of Loess Tunnel Based on Three-Dimensional Numerical Simulation in Different Excavation Length of Invert

2013 ◽  
Vol 405-408 ◽  
pp. 1259-1263
Author(s):  
Zhi Jie Sun ◽  
Jun Min Shen ◽  
Xiao Hui Xue ◽  
Zhong Ming Su
Keyword(s):  
Numerical Simulation ◽  
Plastic Strain ◽  
Working Conditions ◽  
Three Dimensional ◽  
Side Wall ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
3D Finite Element ◽  
Element Simulation ◽  
Wall Position

The 3D finite element simulation was adopted to study the globality stability of tunnel caused by the different excavation length of invert. Kelan-Linxian highway loess tunnels were taken as an example. The research results are shown as follows: The vertical displacement and horizontal convergence increased by the increasing of the excavation length of the invert. But the latter increase range is larger than the former. The horizontal convergence in sidewall is convergence value is greater than the level of the arch and the corner, the horizontal displacement primarily occurred in the side wall position. The surrounding rocks maximum plastic strain occurred in side wall and corner wall in 4 working conditions. The plastic zone occurred around from arch corner to wall side. In Tab. 4, the maximum plastic strain is increased by the excavation length of inverts increasing.

Analysis of Space-Time Effect for Footage of Tunnel-Type Anchorage by Tunneling Cycle

2014 ◽  
Vol 501-504 ◽  
pp. 1749-1752
Author(s):  
Yi Liu ◽  
Fu Quan Ji ◽  
Pei Shuai Chen
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Three Dimensional ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Space Time ◽  
Time Effect ◽  
Tunnel Wall ◽  
Finite Element Software ◽  
Construction Methods

This paper introduces a three-dimensional numerical model of simulating the tunneling cycle of tunnel-type anchorage by the large finite element software ABAQUS. With tunneling cycles, the space-time effect for footage is analyzed comparatively, which are between the tunnel in headings and tunnel in foots. There are three parameters for evaluating the construction methods, that contain vertical displacement of tunnel vault, vertical displacement of tunnel invert, and horizontal displacement of tunnel wall. The results show that all the values of the above parameters are in the control. Hence, the construction methods of the engineering are available.

Research and Design of Laser Accurate Displacement Measurement System

2011 ◽  
Vol 301-303 ◽  
pp. 1289-1292
Author(s):  
Xiao Gang Wang ◽  
Yue Wei Bai ◽  
Kai Liu
Keyword(s):  
Measurement System ◽  
Electric Displacement ◽  
Three Dimensional ◽  
Measurement Data ◽  
Displacement Measurement ◽  
Displacement Sensor ◽  
Laser Displacement Sensor ◽  
Servo Motor ◽  
Wide Range ◽  
Research And Design

Laser displacement sensor(LDS) displacement measurement is a non-contact measurement with more precision and a wide range of applications.。In this paper, a laser accurate displacement measurement system based on LDS and three-dimensional linear-servomotor-driven actuators (3D LSDA) is presented. The 3D LSDA moving system is composed of linear servo motor, precision movable liner mechanism and servo machine. It is driven to move the noncontact laser displacement sensor to scan surfaces through the three-dimensional electric displacement platform, and then the measurement data is processed. The displacement sensor resolution is 2μm; each dimensional electric displacement platform repeated positioning accuracy is higher than 5μm.

Design and calibration of an IVEM for general 3-dimensional imaging of non-diffracting materials

1992 ◽  
Vol 50 (2) ◽  
pp. 1040-1041
Author(s):  
Neil Rowlands ◽  
Jeff Price ◽  
Michael Kersker ◽  
Seichi Suzuki ◽  
Steve Young ◽  
...  
Keyword(s):  
3D Imaging ◽  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
3 Dimensional ◽  
3D Microstructure ◽  
Image Translation ◽  
Digital Correlation ◽  
On Line ◽  
Mechanical Stage ◽  
Projection Angle

Three-dimensional (3D) microstructure visualization on the electron microscope requires that the sample be tilted to different positions to collect a series of projections. This tilting should be performed rapidly for on-line stereo viewing and precisely for off-line tomographic reconstruction. Usually a projection series is collected using mechanical stage tilt alone. The stereo pairs must be viewed off-line and the 60 to 120 tomographic projections must be aligned with fiduciary markers or digital correlation methods. The delay in viewing stereo pairs and the alignment problems in tomographic reconstruction could be eliminated or improved by tilting the beam if such tilt could be accomplished without image translation.A microscope capable of beam tilt with simultaneous image shift to eliminate tilt-induced translation has been investigated for 3D imaging of thick (1 μm) biologic specimens. By tilting the beam above and through the specimen and bringing it back below the specimen, a brightfield image with a projection angle corresponding to the beam tilt angle can be recorded (Fig. 1a).

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