Numerical Simulation Study on Technology of the Top-Down Bored Excavation with Cast-In Situ Arch

2015 ◽  
Vol 744-746 ◽  
pp. 1027-1032
Author(s):  
Zhong Ren Wang
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Practical Significance ◽  
Top Down ◽  
Optimization Analysis ◽  
Flac 3D ◽  
The Stability ◽  
Specific Project ◽  
Stability Of Structure

The top-down bored excavation with cast-in-situ arch method has many advantages, such as forming a complete and stable mechanical structure, reducing construction procedures and the frequency of structure transformation, improving the stability of structure during the construction and so on. According to the specific project of single span top-down bored excavation duct in Changchun Liberation Road station, numerical simulation method is used and finite difference software FLAC 3D is adopted in this paper to analyze and research the applicability of the top-down bored excavation with cast-in-situ arch method to this project. Then optimization analysis for excavation sequence of pilot tunnel is done and the optimum construction scheme is raised to guide the practical project. This research has certain practical significance and also provides references for similar projects.

scholarly journals Study on Compaction Effect and Process of Reclaimed Soil of Nonmetallic Mines in Xinjiang, China

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Kaikai Wang ◽  
Zizhao Zhang ◽  
Guobin Tang ◽  
Xiaodong Tan ◽  
Qianli Lv ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Land Reclamation ◽  
Simulation Method ◽  
Test Method ◽  
Soil Thickness ◽  
In Situ Test ◽  
Factors Affecting ◽  
Reclaimed Soil ◽  
Different Thickness

Reclaimed soil is the key substrate for land reclamation and ecological restoration in the mine areas. The change of the density of reclaimed soil of the nonmetallic mines in Xinjiang during the land reclamation process was studied in this paper. Firstly, the in situ test method of static load was used to simulate the compaction of reclaimed soil with different thickness of overlying soil by different compaction times of mines reclamation machinery, and field in situ test compaction data were obtained. Then, the numerical simulation method was used to simulate the variation process of displacement and porosity at different depths for different thickness of the reclaimed soil under different compaction conditions. The numerical simulation and the in situ test results verified each other to acquire the compaction process and results of reclaimed soil under different compaction. The results showed that the numerical simulation results were consistent with the in situ test. The reclaimed soil thickness and compaction times were crucial factors affecting the compaction effect of the soil. The difference between the three times compaction and the uncompacted soil was obvious, and the effect of single compaction was weakened with the increase of compaction times. Under the same compaction action, the thicker the soil was, the less obvious the compaction effect would be. In the process of reclamation, the compaction effect of the surface part (at the depth of 10 cm) was visible, and the amount of compression and springback was larger. The research results can provide a reference to the land reclamation of nonmetallic mines in Xinjiang, China.

Stability Analysis of Side Slope under Normal and Rainfall Conditions

2013 ◽  
Vol 275-277 ◽  
pp. 1383-1388
Author(s):  
Cheng Liang Zhang ◽  
Lei Liu ◽  
Chun Wang
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Unstable State ◽  
Electrical Method ◽  
Rainfall Condition ◽  
Long Term Stability ◽  
Side Slope ◽  
Numerical Simulation Method ◽  
The Stability ◽  
The Impact

The paper studied a side slope engineering of highway in K29+450~K29+900 sections by making an on-site survey of landform and geological features of the side slope. By combining drilling, high-density electrical method and numerical simulation method, the depth and range of the sliding surface were determined. The stability of the side slope after an excavation in a normal and a rainfall conditions was analyzed using numerical simulation method, and simulation results show that in the normal condition the safety factor of the side slope is 1.12, and it is 1.05 in the rainfall condition; the distribution of plastic zones is wide, especially in the rainfall condition, the side slope has a large deformation and is in an unstable state. When a program of side slope reinforcement is chosen, the impact under rainfall condition should be considered in order to ensure long-term stability of side slope.

scholarly journals Numerical Simulation of the Effect of Dynamic Stress on the Rock Surrounding a Mine Roadway

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jun-hua Xue ◽  
Ke-liang Zhan ◽  
Xuan-hong Du ◽  
Qian Ma
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Rock Burst ◽  
Dynamic Stress ◽  
Simulation Method ◽  
Mining Areas ◽  
Geological Conditions ◽  
Mine Roadway ◽  
The Stability ◽  
Two Sides

In view of the damage of dynamic stress to the rock surrounding a mine roadway during coal mining, based on the actual geological conditions of Zhuji mine in Huainan, China, a UDEC model was established to study the influences of the thickness and strength of the direct roof above the coal seam and the anchorage effect on the stability of the roadway. The failure mechanism and effect of the dynamic stress on the rock surrounding a mine roadway were revealed. Under dynamic stress, cracks appear near the side of the roadway where the stress is concentrated. These cracks rapidly expand to the two sides of coal and rock mass. At the same time, the coal and rock mass at the top of the roadway fall, and finally, the two sides of coal and rock mass were broken and ejected into the roadway, causing a rock burst. However, when the same dynamic stress is applied to the roadway after supports are installed, there is no large-deformation failure in the roadway, which shows that, under certain conditions, rock bolting can improve the stability and seismic resistance of the surrounding coal and rock mass. Furthermore, by simulating the failure of surrounding rock with different strengths and thicknesses in the immediate roof, it is found that the thinner the roof, the greater the influence of the dynamic stress on the roadway; the stronger the roof is, the more likely the rock burst will occur with greater intensity under the same dynamic stress. A numerical simulation method was used to analyze the factors influencing rock bursting. The results provide a theoretical basis for research into the causes and prevention of rock bursts in deep mining areas.

scholarly journals Research on Stability Design of Differential Drive Fork-Type AGV Based on PID Control

Electronics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1072
Author(s):  
Tingting Wang ◽  
Ruoyan Dong ◽  
Rui Zhang ◽  
Dongchen Qin
Keyword(s):  
Control System ◽  
Pid Control ◽  
Simulation Method ◽  
Automated Guided Vehicles ◽  
Steering Control ◽  
Fuzzy Pid Control ◽  
Theoretical Derivation ◽  
Work Requirements ◽  
The Stability

As one of the important components of intelligent warehousing logistics, Automated Guided Vehicles (AGVs) have greatly improved the efficiency of warehousing operations. AGVs are responsible for the delivery of goods in warehousing and logistics, and it is extremely important to maintain a stable running state. In this paper, an AGV in-situ steering dynamic model is established according to the actual size, and the center deviation phenomenon during AGV steering is theoretically analyzed to obtain the parameters that affect the AGV’s in-situ steering stability. Secondly, the dynamic simulation method is used to analyze the law of the stability of the AGV in-situ steering parameters to verify the correctness of the theoretical derivation equation. According to the analysis results, the motion parameters related to AGV in-situ steering are analyzed, and a reasonable design scheme is given. Based on the optimized fork-type AGV, the AGV in-situ steering control strategy is studied, and the adaptive fuzzy PID control algorithm is used to construct the fork-type AGV steering control system. Then the software and hardware design of the AGV steering control system is carried out. The optimized fork-type AGV has been turned to work stably after commissioning, meeting the actual work requirements.

The Stability Analysis of Tailings Dam under the Fluid-Solid Coupled Interaction

2012 ◽  
Vol 204-208 ◽  
pp. 3078-3081
Author(s):  
Kun Yang ◽  
Hao Han ◽  
Zhi Chao Ma
Keyword(s):  
Stability Analysis ◽  
Coupled Model ◽  
Simulation Method ◽  
Practical Significance ◽  
Coupled Analysis ◽  
Tailings Dam ◽  
Sliding Surface ◽  
Seepage Field ◽  
Coupling Analysis ◽  
The Stability

Numerical simulation method is adopted to analysis the stability of tailings dam under the fluid-solid coupled interaction. Using the full-coupled analysis function, stress field 、seepage field and their coupled model are studied in this paper. Finally, the critical sliding surface of the tailings dam is searched. Results show that the safety factor after coupling is smaller than before. It illustrates that the fluid-solid coupling analysis has an important practical significance for the stability analysis of tailings dam.

The Analys of Stability of Composite Soil Nail

2014 ◽  
Vol 580-583 ◽  
pp. 503-508 ◽  
Author(s):  
Yong Zeng
Keyword(s):  
New Technology ◽  
Practical Significance ◽  
Soil Nailing ◽  
Local Conditions ◽  
Soil Nail ◽  
Composite Soil Nailing ◽  
The Stability ◽  
The Right ◽  
Organic Combination ◽  
Stability Of Structure

Composite soil nailing technology is a new technology which developed on the basis of the soil nailing supporting technology. This new technology has a very important practical significance to the construction, for which the scale is larger and larger, the condition is more and more complex and the excavation of foundation is more and more deep. Composite soil nailing technique is mainly introduced in this paper by its main form of structure and the main principle, which draw a conclusion that different forms of the combination of support types have different effects on the stability of structure, by analyzing the support stability. This thesis shows that we should adjust measures to local conditions, choose the right organic combination. At the same time it also provides the basis for the practical application of engineering support.

Stability Numerical Simulation of Daping Landslide Group to Sunjiaya Tunnel

2012 ◽  
Vol 170-173 ◽  
pp. 413-417
Author(s):  
Wen She He ◽  
Long Yuan ◽  
Shuang Mei Chang
Keyword(s):  
Numerical Simulation ◽  
Limit Equilibrium ◽  
Simulation Method ◽  
Work Conditions ◽  
Sliding Surface ◽  
Tunnel Engineering ◽  
Safety Factors ◽  
Easy Method ◽  
Stability Of Slope ◽  
The Stability

The stability of two profile, with No.Ⅲ landslide of Daping landslide group near the tunnel engineering of Sunjiaya, was respectively discussed using limit equilibrium and numerical simulation method at operation one (gravity) and two (gravity+rainstorm) in this paper. The dangerous sliding surface and corresponding safety factors was calculated by limit equilibrium method, to upper and lower parts of No.Ⅲ landslide in two different work conditions. The model of two calculation profiles was established and the dangerous sliding surface and corresponding safety factors was simulated by finite difference software of FLAC3D for upper and lower parts of No.Ⅲ landslide at two operations. Compared with limit equilibrium, FLAC3D is a simple and easy method to analyze the stability of slope.

Hybrid Projective Synchronization of a New Hyperchaotic System

2010 ◽  
Vol 42 ◽  
pp. 63-67
Author(s):  
Jie Fang ◽  
Xiao Ming Zhang ◽  
Chang Sheng Jiang
Keyword(s):  
Numerical Simulation ◽  
Chaos Synchronization ◽  
Projective Synchronization ◽  
Practical Significance ◽  
Hyperchaotic System ◽  
Complete Synchronization ◽  
Full State ◽  
Hybrid Projective Synchronization ◽  
The Stability ◽  
New Hyperchaotic System

The full state hybrid projective synchronization, which includes complete synchronization, anti-synchronization and projective synchronization as its special item, is a novel type of chaos synchronization, so the research in this area has high practical significance. This paper is involved with full state hybrid projective synchronization of a new hyperchaotic system. Based on the stability criterion of linear system, full state hybrid projective synchronization is achieved by appropriate linear separation. Numerical simulation is presented to demonstrate the effectiveness of the proposed method.

Numerical Optimization Analysis of the Construction Sequence of PBA Group Hole

2014 ◽  
Vol 501-504 ◽  
pp. 2199-2204
Author(s):  
Heng Qian Hu
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Numerical Optimization ◽  
Ground Surface ◽  
Simulation Method ◽  
Tunnel Construction ◽  
Optimization Analysis ◽  
Construction Sequence ◽  
Finite Element Software ◽  
Construction Model

Based on the PBA construction method of Changchun Liberation Road station metro line No.2, in order to get the optimization of construction sequence of six pilot tunnels, we use numerical simulation method and finite element software MIDAS GTS to establish the construction model of the station pilot tunnel. After comparing four excavation methods of the surface subsidence, we come to a conclusion that first up then down and first side then middle is the optimal excavation scheme. At the same time, we make models to analysis the necessity of making advance support before pilot tunnel construction. Pipe shed and small duct grouting pre support is very significant to the control of the subsidence of ground surface and vault.

scholarly journals Optimization for U-Shaped Steel Support in Deep Tunnels under Coupled Static-Dynamic Loading

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Yujun Zuo ◽  
Jian Wang ◽  
Longjun Dong ◽  
Weiwei Shu ◽  
Meilu Yu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Dynamic Loading ◽  
Contact Area ◽  
Simulation Method ◽  
Surrounding Rock ◽  
Perturbation Equation ◽  
Lateral Stress ◽  
High Geostress ◽  
The Stability ◽  
Tunnel Instability

With the effects of high geostress and intensive dynamic disturbances in deep mining, the stability and safety of tunnels are seriously affected. The optimization for U-shaped steel support is of vital significance and can solve the problems of cost reduction and tunnel instability. Based on the perturbation equation, a coupled formula for U-shaped steel and the surrounding rock mass was proposed to evaluate the practical stability of a U-shaped steel support. Through a numerical simulation method, the characteristics of U-shaped steel support can be obtained under coupled static-dynamic loading. Furthermore, the field test was carried out and compared with the numerical simulation, which was discussed. The results show that there will be a stress concentration when the contact area is small. In addition, the concentrated stress will release with the increase in contact area. With the increase in the lateral stress coefficient, the deformation exhibits a downward trend under static loading, indicating that the lateral stress is the dominant force driving the deep geostress activity. The support requirement of this section of surrounding rock can be satisfied by a U-shaped steel group with 1.5 m spacing under dynamic disturbance.

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