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.

Three-dimensional adaptive fixed-time guidance law against maneuvering targets with impact angle constraints and control input saturation

2021 ◽  
pp. 014233122110598
Author(s):  
Fei Ma ◽  
Yunjie Wu ◽  
Siqi Wang ◽  
Xiaofei Yang ◽  
Yueyang Hua
Keyword(s):  
Sliding Mode ◽  
Input Saturation ◽  
Three Dimensional ◽  
Fixed Time ◽  
Impact Angle ◽  
Guidance System ◽  
Control Input ◽  
Guidance Law ◽  
The Stability ◽  
And Control

This paper presents an adaptive fixed-time guidance law for the three-dimensional interception guidance problem with impact angle constraints and control input saturation against a maneuvering target. First, a coupled guidance model formulated by the relative motion equation is established. On this basis, a fixed-time disturbance observer is employed to estimate the lumped disturbances. With the help of this estimation technique, the adaptive fixed-time sliding mode guidance law is designed to accomplish accurate interception. The stability of the closed-loop guidance system is proven by the Lyapunov method. Simulation results of different scenarios are executed to validate the effectiveness and superiority of the proposed guidance law.

scholarly journals Analysis of suspension bridge tunnel-type anchorage construction on the stability of surrounding rock

2020 ◽  
Vol 198 ◽  
pp. 02006
Author(s):  
Nana Li ◽  
Yongqiang Zhou ◽  
Yanqiang Zhao ◽  
Guiju Li
Keyword(s):  
Suspension Bridge ◽  
Surrounding Rock ◽  
Construction Process ◽  
Analysis Model ◽  
Stability Of Surrounding Rock ◽  
Numerical Software ◽  
Left And Right ◽  
Simulation Results ◽  
The Stability ◽  
The Right

In order to study the interaction between the left and right tunnels of suspension bridge tunnel-type anchorage, the finite difference numerical software is used to analyze the mechanical properties of the surrounding rock during the construction process. A numerical analysis model based on FLAC3D is established to analyze the stress, displacement and plastic zone changes of the surrounding rock of right tunnel anchor cavern during the construction of left tunnel anchor cavern. The right tunnel anchor cavern is excavated firstly, and then the left tunnel anchor cavern is excavated. The numerical simulation results show that the main displacement of the right tunnel occurs in the construction stage of the anchor plug body and the rear anchor cavern of the left tunnel. During the excavation of the left tunnel, the plastic zones of the left and right tunnel anchor caverns are only connected above the middle of the waist wall. Therefore, it is suggested that during the construction process, especially in the excavation stage of the anchor plug body and the rear anchor cavern, the area above the middle of the tunnel waist wall should be strengthened in time to ensure the construction safety.

Instability Mechanism of Du Yun Pass Tunnel Entrance Weathered Stacking Area Analysis

2016 ◽  
Vol 858 ◽  
pp. 81-85
Author(s):  
Lin Liu ◽  
Yao Rong ◽  
Cheng Ke Zhang ◽  
Meng Yun Mao ◽  
Lu Lin Zhang
Keyword(s):  
Pile Foundation ◽  
Stability Problem ◽  
Surrounding Rock ◽  
Geological Condition ◽  
Construction Process ◽  
Instability Mechanism ◽  
Construction Scheme ◽  
The Stability ◽  
Tunnel Portal ◽  
Tunnel Entrance

The stability of the tunnel portal section under poor terrain and geological condition has always been the focus of construction safety. The stability problem has become more complex for the erosion accumulation area under the valley. In this paper, firstly the stability of the tunnel portal is classified. Combined with engineering cases, the FEM numerical method is used to simulate the supporting structure and construction process of the tunnel. Based on the distribution of the plastic zone and displacement of surrounding rock, the mechanism of the instability of the tunnel portal is analyzed. Through the optimized construction scheme that arranges pile foundation in tunnel arch foundation, the bearing capacity of foundation has been greatly improved, which has effectively prevented the instability of surrounding rock caused by the slope deformation and foundation settlement. The conclusions that have been drawn in this paper can be used for reference for related projects.

Research on Spacial Displacement Regulations in Soft Surrounding Rock Tunnel

2013 ◽  
Vol 690-693 ◽  
pp. 886-889
Author(s):  
Bao Long Lin
Keyword(s):  
High Speed ◽  
Surrounding Rock ◽  
Construction Process ◽  
High Speed Rail ◽  
Tunnel Stability ◽  
Construction Methods ◽  
Minimum Principal Stress ◽  
Initial Support ◽  
Rock Tunnel ◽  
Weak Surrounding Rock

Based on the engineering background of Dongkeling tunnel of Guizhou-Guangzhou high-speed rail, construction process in soft surrounding rock is simulated by using finite difference software——FLAC according to large-deformation characteristics in water-rich and weathering altered granite weak surrounding rock. Several aspects, such as vault settlement, invert uplift, clearance convergence, surface settlement, the maximum and minimum principal stress of the initial support and plastic zone of surrounding rock, are analyzed to determine the tunnel stability with different construction methods.

Numerical Analysis on the Influence of Joints Inclination on the Characteristics of Deformation and Stability of Tunnel

2013 ◽  
Vol 790 ◽  
pp. 299-305
Author(s):  
Xiao Song Tang ◽  
Yong Fu Wang ◽  
Ying Ren Zheng
Keyword(s):  
Stability Analysis ◽  
Numerical Analysis ◽  
Calculation Method ◽  
Research Result ◽  
Bending Moment ◽  
Surrounding Rock ◽  
Interface Element ◽  
Tunnel Stability ◽  
Stability Of Surrounding Rock ◽  
The Stability

The paper adopts the interface element to simulate the joints so as to systematically and quantitatively study the deformation around tunnel, the mechanic state of lining and the stability under different inclining angles of joints. The result shows that the deformation around tunnel deteriorates mainly along the joint during the inner convergence effects of surrounding rock. When the inclining angle α=45°, the deformation around the tunnel is most serious, followed by that when α=90°, α=60°, α=30° and α=0°. At the same time, the influence of inclining angle on the distribution of the axial force of lining is comparatively small. But the distribution of bending moment and shear change obviously where the joints penetrate the tunnel. The tunnel stability of surrounding rock is the poorest when α=90° and the tunnel is most stable when α=0°. The stability of surrounding rock changes little when α is between 30° and 60°. The research result provides an effective calculation method for the forecast of deformation, the design of structure and the stability analysis of jointed tunnel. It is also helpful for the monitoring of construction and calculation of jointed tunnel in the future.

Influence of Structural Plane in Similar Soil Surrounding Rock on Excavation Stability

2010 ◽  
Vol 168-170 ◽  
pp. 1318-1324
Author(s):  
Qiang Chen ◽  
Wei Tao Chen ◽  
Guo Wei Meng
Keyword(s):  
Numerical Calculation ◽  
Surrounding Rock ◽  
Disintegration Time ◽  
Structural Plane ◽  
Research Results ◽  
Tunnel Stability ◽  
Excavation Stability ◽  
Shearing Strength ◽  
The Stability ◽  
Similar Soil

Lots of primary or secondary structural planes in similar soil surrounding rock are the main difference with Quaternary soil surrounding rock, but the particularity isn’t considered in the analysis of tunnel stability. The fact, which similar soil surrounding rock has most weak structural planes, is testified by engineering examples. The influence of structural plane in similar soil surrounding rock on excavation stability was analyzed through combining theory with disintegration test and numerical calculation. The research results show that there are a lot of structural planes in similar soil surrounding rock. The angle between structural planes and tunnel axes and shearing strength of structural planes control the stability of tunnel. Disintegration time of soil is shortened due to structural planes. On a certain condition, structural planes can induce local collapse in soil surrounding rock while excavating.

scholarly journals Displacement Prediction of Surrounding Rock in Tunnel Based on cellular ant algorithm

2021 ◽  
Vol 236 ◽  
pp. 03026
Author(s):  
Li Yongyu ◽  
Wang Yu ◽  
Wang Shihua
Keyword(s):  
Neural Network ◽  
Linear Relationship ◽  
Neural Network Model ◽  
Surrounding Rock ◽  
Ant Algorithm ◽  
Displacement Prediction ◽  
Stability Of Surrounding Rock ◽  
Key Factor ◽  
The Stability ◽  
And Control

The deformation of tunnel surrounding rock is the key factor to analyze the stability of surrounding rock. However, due to the influence of many factors and the strong non-linear relationship between the factors, it is difficult to predict the deformation effectively. In this paper, a method based on cellular ant neural network model is proposed to simulate the displacement of surrounding rock with time. The results show that this method is efficient and feasible, and can meet the requirements of engineering and control.

Cutting Stability Analysis under the Influence of Blasting

2012 ◽  
Vol 170-173 ◽  
pp. 3035-3040
Author(s):  
Peng Fei Xiao ◽  
Wen Xue Gao ◽  
Bing Hui Hou ◽  
Ning Ning Chen
Keyword(s):  
Time History ◽  
Slope Instability ◽  
Construction Process ◽  
Protective Measures ◽  
Field Displacement ◽  
History Analysis ◽  
Blasting Excavation ◽  
Reconstruction Project ◽  
Vibration Wave ◽  
The Stability

The blasting effect is an important factor to influence the stability of the slope blasting construction, understanding the reasons of the slope instability under blasting construction, taking reasonable effective protective measures, which can greatly reduce slope instability phenomena during the construction. Combining with the 111 national highway (Tanghekou ~Beijing boundary) reconstruction project, through numerical simulation, using strength reduction fem for time history analysis, discuss under blast loads slope's the stress field, displacement field and the spread rule of vibration wave, systematically analysis blasting excavation impact on slope stability summarizing in construction process the question should be pay attention ,which can be a guidance for relevant similar engineering design and construction.

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.

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.

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