scholarly journals A Large Goaf Group Treatment by means of Mine Backfill Technology

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Hanwen Jia ◽  
Baoxu Yan ◽  
Erol Yilmaz
Keyword(s):  
Group Treatment ◽  
Laser Scanning ◽  
Large Scale ◽  
Mechanical Characteristics ◽  
Three Dimensional ◽  
Stability Diagram ◽  
Surrounding Rock ◽  
Mine Backfill ◽  
Treatment Scheme ◽  
The Stability

There are few studies on the management methods of large-scale goaf groups per the specific surrounding rock mass conditions of each goaf. This paper evaluates comprehensively the stability of the multistage large-scale goaf group in a Pb-Zn mine in Inner Mongolia, China, via the modified Mathews stability diagram technique. The volume of each goaf to be backfilled was quantitatively analyzed in the combination of theoretical analysis and three-dimensional laser scanning technology. The corresponding mechanical characteristics of the filling were determined by laboratory testing while formulating the treatment scheme of the large goaf group using the backfill method. The applicability of the treatment scheme using the backfill was verified by the combination of the numerical results of the distribution of the surrounding rock failure zone and the monitored data of the surface subsidence. The research results and treatment scheme using the backfill can provide a reference for similar conditions of mines worldwide.

scholarly journals Weighing trees with lasers: advances, challenges and opportunities

2018 ◽  
Vol 8 (2) ◽  
pp. 20170048 ◽  
Author(s):  
M. I. Disney ◽  
M. Boni Vicari ◽  
A. Burt ◽  
K. Calders ◽  
S. L. Lewis ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Large Scale ◽  
Three Dimensional ◽  
Point Clouds ◽  
3D Models ◽  
Tree Form ◽  
Form And Function ◽  
Challenges And Opportunities ◽  
And Function ◽  
Non Destructive

Terrestrial laser scanning (TLS) is providing exciting new ways to quantify tree and forest structure, particularly above-ground biomass (AGB). We show how TLS can address some of the key uncertainties and limitations of current approaches to estimating AGB based on empirical allometric scaling equations (ASEs) that underpin all large-scale estimates of AGB. TLS provides extremely detailed non-destructive measurements of tree form independent of tree size and shape. We show examples of three-dimensional (3D) TLS measurements from various tropical and temperate forests and describe how the resulting TLS point clouds can be used to produce quantitative 3D models of branch and trunk size, shape and distribution. These models can drastically improve estimates of AGB, provide new, improved large-scale ASEs, and deliver insights into a range of fundamental tree properties related to structure. Large quantities of detailed measurements of individual 3D tree structure also have the potential to open new and exciting avenues of research in areas where difficulties of measurement have until now prevented statistical approaches to detecting and understanding underlying patterns of scaling, form and function. We discuss these opportunities and some of the challenges that remain to be overcome to enable wider adoption of TLS methods.

Potential Flow Field Generated by Downstream Moving Bars and Propagated on a Turbine Blade at Low Reynolds Number

2011 ◽  
Author(s):  
Ve´ronique Penin ◽  
Pascale Kulisa ◽  
Franc¸ois Bario
Keyword(s):  
Boundary Layer ◽  
Large Scale ◽  
Numerical Study ◽  
Three Dimensional ◽  
Potential Effect ◽  
Navier Stokes ◽  
Turbine Cascade ◽  
Wake Interaction ◽  
Rotor Stator Interaction ◽  
The Stability

During the last few decades, the size and weight of turbo-machinery have been continuously reduced. However, by decreasing the distance between rows, rotor-stator interaction is strengthened. Two interactions now have the same magnitude: wake interaction and potential effect. Studying this effect is essential to understand rotor-stator interactions. Indeed, this phenomenon influences the whole flow, including the boundary layer of the upstream and downstream blades, ergo the stability of the flow and the efficiency of the machine. A large scale turbine cascade followed by a specially designed rotating cylinder system is used. Synchronised velocity LDA measurements on the vane profile show the flow and boundary layer behavior due to the moving bars. To help the general understanding and to corroborate our experimental results, numerical investigations are carried out with an unsteady three dimensional Navier-Stokes code. Moreover, the numerical study informs about the potential disturbance to the whole flow of the cascade.

scholarly journals Fine Exploration and Control of Subway Crossing Karst Area

2019 ◽  
Vol 9 (13) ◽  
pp. 2588 ◽  
Author(s):  
Jing Wang ◽  
Liping Li ◽  
Shaoshuai Shi ◽  
Shangqu Sun ◽  
Xingzhi Ba ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Treatment Method ◽  
Surrounding Rock ◽  
Karst Area ◽  
Actual Situation ◽  
Construction Process ◽  
Tunnel Stability ◽  
Field Displacement ◽  
The Stability ◽  
And Control

A large number of subway projects need to cross all kinds of disaster sources during the construction process. When a disaster source is unknown and uncertain, it is difficult for tunnel stability analysis to conform to the actual situation, which is likely to cause serious geological disasters. Firstly, the accurate location of the source of the disaster is realized via the geophysical method, and the orientation of the target is determined. Secondly, real imaging of the geological disaster source is realized using fine three-dimensional scanning equipment. Finally, the coupling law of the seepage field, displacement field, and stress field of the tunnel surrounding rock are analyzed. The stability of the tunnel is analyzed, and the reasonable karst treatment method is put forward.

scholarly journals Performance Assessment of Reference Modelling Methods for Defect Evaluation in Asphalt Concrete

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8190
Author(s):  
Pauli Putkiranta ◽  
Matti Kurkela ◽  
Matias Ingman ◽  
Aino Keitaanniemi ◽  
Aimad El Issaoui ◽  
...  
Keyword(s):  
High Resolution ◽  
Cross Sections ◽  
Laser Scanning ◽  
Large Scale ◽  
Three Dimensional ◽  
Qualitative Assessment ◽  
Three Dimensional Mapping ◽  
Road Surfaces ◽  
Three Dimensional Measurement ◽  
Mobile Methods

The deterioration of road conditions and increasing repair deficits pose challenges for the maintenance of reliable road infrastructure, and thus threaten, for example, safety and the fluent flow of traffic. Improved and more efficient procedures for maintenance are required, and these require improved knowledge of road conditions, i.e., improved data. Three-dimensional mapping presents possibilities for large-scale collection of data on road surfaces and automatic evaluation of maintenance needs. However, the development and, specifically, evaluation of large-scale mobile methods requires reliable references. To evaluate possibilities for close-range, static, high-resolution, three-dimensional measurement of road surfaces for reference use, three measurement methods and five instrumentations are investigated: terrestrial laser scanning (TLS, Leica RTC360), photogrammetry using high-resolution professional-grade cameras (Nikon D800 and D810E), photogrammetry using an industrial camera (FLIR Grasshopper GS3-U3-120S6C-C), and structured-light handheld scanners Artec Leo and Faro Freestyle. High-resolution photogrammetry is established as reference based on laboratory measurements and point density. The instrumentations are compared against one another using cross-sections, point–point distances, and ability to obtain key metrics of defects, and a qualitative assessment of the processing procedures for each is carried out. It is found that photogrammetric models provide the highest resolutions (10–50 million points per m2) and photogrammetric and TLS approaches perform robustly in precision with consistent sub-millimeter offsets relative to one another, while handheld scanners perform relatively inconsistently. A discussion on the practical implications of using each of the examined instrumentations is presented.

scholarly journals Experimental Study on Structural Form and Excavation Model of Urban Metro Cross Transfer Station with Super Large Cross Section and Shallow Excavation

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zhi Lin ◽  
Xiang Chen ◽  
Hongyun Yang ◽  
Chongguo Cheng ◽  
Huasong Wang ◽  
...  
Keyword(s):  
Large Scale ◽  
Ground Surface ◽  
Construction Method ◽  
Surrounding Rock ◽  
Structure Form ◽  
Large Section ◽  
Response Characteristics ◽  
Ground Surface Settlement ◽  
Transfer Structure ◽  
The Stability

The construction of urban underground cross-interchange transfer subway stations often encounters the difficulties of shallow-buried, different surrounding rock, large spans and heights, congested road traffic, and surrounding buildings sensitive to the construction sequence. Therefore, there is a need for an underground project that controls the stability of underground space and ground subsidence. Based on the construction difficulties of a certain station (the maximum excavation area over 760 m2), this paper conducts a comprehensive selection design of the structure, construction mechanics response, and control technology of this type of interchange station structure and construction excavation. First of all, based on the design experience of large-scale underground transfer transportation engineering and taking full consideration of the stratum conditions, an “arch-wall” cross transfer structure method is proposed. The refined numerical analysis shows that the structure can fully utilize the stratum conditions to reduce the ground surface settlement. Then, in view of the stability of surrounding rock during the construction of a large section, based on the traditional large section excavation method, a construction method of “cross rock beam + heading method” was proposed. In order to verify the effect of the construction method, the three-dimensional detailed numerical model was used to simulate the construction conditions, and the mechanical response characteristics and displacement changes of surrounding rock under each excavation step are explored. Simultaneous interpreting with the traditional large section excavation method, the results show that the new method has advantages in controlling the stability of the surrounding rock. Meanwhile, in order to ensure the safe construction of the project, the self-developed multifunctional engineering test system for traffic tunnels is used to carry out a large-scale physical model experiment to simulate the entire process of the “arch-wall” cross transfer structure construction response characteristics. By analyzing the data of measuring points, the results show that the structure form and the excavation method cause the ground surface settlement, stress, and structural forces meet the requirements for safe construction. Finally, the station can be safely constructed under the new structure form and construction method. Therefore, the structure form and method proposed in this paper can be adapted to the large-scale underground structure under construction in complex environments.

scholarly journals Transparent Collision Visualization of Point Clouds Acquired by Laser Scanning

2019 ◽  
Vol 8 (9) ◽  
pp. 425
Author(s):  
Weite Li ◽  
Kenya Shigeta ◽  
Kyoko Hasegawa ◽  
Liang Li ◽  
Keiji Yano ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Large Scale ◽  
Three Dimensional ◽  
Point Clouds ◽  
City Government ◽  
Three Dimensional Objects ◽  
Kyoto City ◽  
Risk Areas ◽  
Scale Point ◽  
The City

In this paper, we propose a method to visualize large-scale colliding point clouds by highlighting their collision areas, and apply the method to visualization of collision simulation. Our method uses our recent work that achieved precise three-dimensional see-through imaging, i.e., transparent visualization, of large-scale point clouds that were acquired via laser scanning of three-dimensional objects. We apply the proposed collision visualization method to two applications: (1) The revival of the festival float procession of the Gion Festival, Kyoto city, Japan. The city government plans to revive the original procession route, which is narrow and not used at present. For the revival, it is important to know whether the festival floats would collide with houses, billboards, electric wires, or other objects along the original route. (2) Plant simulations based on laser-scanned datasets of existing and new facilities. The advantageous features of our method are the following: (1) A transparent visualization with a correct depth feel that is helpful to robustly determine the collision areas; (2) the ability to visualize high collision risk areas and real collision areas; and (3) the ability to highlight target visualized areas by increasing the corresponding point densities.

Design and Manufacture of a New Large-Scale Three-Dimensional Geomechanics Model Test System

2010 ◽  
Vol 97-101 ◽  
pp. 2770-2773
Author(s):  
Wei Shen Zhu ◽  
Yong Li ◽  
Min Yong ◽  
Q.B. Zhang ◽  
Shu Cai Li
Keyword(s):  
Model Test ◽  
Large Scale ◽  
Three Dimensional ◽  
Great Depth ◽  
Test System ◽  
Great Stability ◽  
Underground Caverns ◽  
Structural Frame ◽  
The Stability ◽  
Design And Manufacture

Geomechanics modeling has played important role in geotechnical engineering. In order to investigate on the stability of underground caverns at great depth, a large-scale geomechanics model test system was designed and manufactured. The system mainly consisted of a steel structural frame and a hydraulic loading control system, which can apply active loading on six sides with a true three-dimensional stress state. Newly developed combinational ball sliding walls were installed on each of the major loading surfaces, which were significantly reduced the friction due to model deformation. The system has apparent technical advantages such as high stiffness, great stability, and flexibility of assembly, and easy adjustment of its dimensions.

scholarly journals Reasonable Layout of Roadway Based on PSO-AHP Optimization Algorithm Under Three-Dimensional Stress Field

2021 ◽  
Author(s):  
Hongbao Zhao ◽  
Hui Cheng ◽  
Chi Zhang ◽  
Yixiao Zhang
Keyword(s):  
Stress Field ◽  
Optimization Algorithm ◽  
Three Dimensional ◽  
Surrounding Rock ◽  
Deviatoric Stress ◽  
Analytic Hierarchy ◽  
Working Face ◽  
Dip Angle ◽  
The Stability ◽  
Hierarchy Process

Abstract Reasonable roadway layout is the fundamental measure to reduce the difficulty of roadway support and improve the stability of surrounding rock. The particle swarm optimization and analytic hierarchy process (PSO-AHP) algorithm of reasonable layout of roadway under the three-dimensional field was proposed, and an engineering verification was carried out in Weijiadi coal mine. The results showed that, The dip angle α1 and azimuth angle α2 affect the distribution of the deviatoric stress of the roadway surrounding rock. Under different stress field, the sensitivity of surrounding rock to α1 and α2 are different. Changing the more sensitive layout parameters can minimize the deviatoric stress and improve the stability of roadway. The PSO-AHP optimization algorithm takes the deviatoric stress as the index to calculate the layout parameters of different parts of the roadway, and then determines the optimal layout parameters through the evaluation function. The roadway of 1104 working face was arranged with the optimal parameters obtained by PSO-AHP optimization algorithm. Compared with the original layout scheme, the deviatoric stress of surrounding rock was reduced and the position of maximum deviatoric stress is transferred. The optimum layout of roadway was combined with an asymmetric support which had a good application effect.

Experimental-Theoretical Method for Defining Physical-Mechanical Properties of Polymer Materials with Regard to Change of Their Physical-Chemical Properties

2012 ◽  
Vol 2 (1) ◽  
pp. 12-24 ◽  
Author(s):  
Gabil G. Aliyev
Keyword(s):  
Mechanical Characteristics ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Theoretical Method ◽  
Polymer Materials ◽  
Liquid Media ◽  
One Dimensional ◽  
Linear Elastic ◽  
Corrosive Liquid ◽  
The Stability

In this paper, an experimental-theoretical method is suggested for defining physical-mechanical characteristics of polymer materials with regard to influence of corrosive liquid media. Experimental dependences of mechanical characteristics on a swelling function are given for a series of polymer materials. One dimensional and three-dimensional linear-elastic models of body deformation with regard to influence of corrosive liquid media are suggested. A new phenomenon, bulging of a polymer strip rigidly fastened by both ends because of swilling forces, is established. The stability criterion is given for a strip made of a polymer material situated under the action of swelling forces only.

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