Numerical Simulation Analysis on a Construction Method of Ultra-Closing Over-Cross Transportation Tunnels

2011 ◽  
Vol 261-263 ◽  
pp. 1287-1291
Author(s):  
He Ran Yu ◽  
Xiao Jun Zhou ◽  
Xiao Bo Wang
Keyword(s):  
Numerical Simulation ◽  
Mechanical Behavior ◽  
Simulation Analysis ◽  
Construction Method ◽  
Simulation Approach ◽  
Construction Period ◽  
New Construction ◽  
The Stability ◽  
Close Distance

By numerical simulation approach, this paper analyzed a new construction method for over-cross tunnel. In this method one concrete framework and two connecting walls were used in the intersection zone to meet the requirement of ultra-close distance between the two tunnels: the lining of upper tunnel rode through on the lower one’s via two connecting walls. This paper conducted a series of study on the mechanical behavior of rocks and structures during the construction period. The stability of the structure and the feasibility of construction method were evaluated.

scholarly journals Modeling the Spatial and Temporal Evolution of Stress during Multiworking Face Mining in Close Distance Coal Seams

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yong Zhang ◽  
Jinkun Yang ◽  
Jiaxuan Zhang ◽  
Xiaoming Sun ◽  
Chen Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Temporal Evolution ◽  
Coal Pillar ◽  
Coal Seams ◽  
Geological Conditions ◽  
Coal Pillars ◽  
The Stability ◽  
Close Distance ◽  
Close Distance Coal Seams

Mining in close distance coal seams (CDCSs) is frequently associated with engineering disasters because of the complicated nature of stress distribution within CDCSs. In order to establish a layout of a roadway to minimize the occurrence of disasters associated with mining CDCS, here the spatial and temporal evolution of stress distribution during the multiworking face mining of a CDCS was explored through numerical simulation based on the engineering and geological conditions of the Nantun Coal Mine. The numerical simulation results indicate that, after the extraction of adjacent multiple working faces, the spatial distribution of stress can be characterized with areas of increased, reduced, and intact stress. The superposed stress of inclined seams that are very close to each other propagates through coal pillars in the bottom floor, and this propagation follows neither the line along the axis of the coal pillar nor the line perpendicular to the direction of the floor. It instead propagates along a line angled with the axis of the coal pillar. The roadway can be arranged in the area with reduced stress, to improve its the stability. Based on the computed spatial and temporal evolution of stress, an optimized layout of roadway was proposed. This layout features a reasonable interval between the mining roadway and a minimal proportion of increased stress areas along the mining roadway and is aligned with geological structures.

The Connection Form of the Beam and Column in Prefabricated Concrete Structure

2014 ◽  
Vol 578-579 ◽  
pp. 818-821
Author(s):  
Ming Li ◽  
Hai Yang Zhang ◽  
Wei Jian Zhao ◽  
Yu Ting Wen
Keyword(s):  
Mechanical Behavior ◽  
Concrete Structure ◽  
Connection Form ◽  
Construction Period ◽  
The Future ◽  
The Stability

The prefabricated construction is widely used because of it has short construction period and can be produced automatic. It has become one of the research focuses of scholars domestic and overseas that how to connect the prefabricate components in the structure to ensure the stability of the whole structure and mechanical behavior. The connection forms of beam and column are overviewed, including the dapped-end connection, the corbel connection, the weld connection, the cast-in-situ monolithic connection, the ductile rod connection, and the pre-stressed fabricated connection. Finally, the problems needed to be further study in the future are discussed.

scholarly journals Theoretical Research and Numerical Simulation on Water Resistance Mechanism of Textile Bag in Water Passage

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Ang Li ◽  
Yuxuan Yang ◽  
Mingcheng Zhu ◽  
Wenzhong Zhang ◽  
Bingnan Ji ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Theoretical Analysis ◽  
Water Resistance ◽  
Simulation Analysis ◽  
Water Pressure ◽  
Water Inrush ◽  
Deformation Characteristics ◽  
Water Blocking ◽  
The Stability ◽  
Water Passage

It is an important problem in the mine water disaster prevention and control to control the large passage moving water. Traditional grouting technology is to put coarse aggregate and fine aggregate downward first and then grouting treatment. But the aggregate and cement flow distance is long, consumption is large, cost is high, and easy to appear secondary water inrush. Centering on the technical difficulties in the rapid construction of the blocking body of the moving water passage, a water-blocking textile bag was invented. The purpose of blocking the tunnel water inrush was achieved by grouting inside the bag body, which fundamentally realized the rapid blocking of the large passage through water under the condition of moving water. However, the mechanism, water plugging law, and design parameters of water blocking roadway with textile bag are still unclear. In this paper, the slip law and stability of the textile bag in the moving water and the deformation characteristics caused by the dynamic water pressure are theoretically analyzed and simulated. Through theoretical analysis, the ultimate antihydraulic stress value of a textile bag of a certain specification is calculated, and the parameters of the textile bag that affect the stability of the bag body are also determined. Xflow was used for numerical simulation analysis to study the deformation characteristics of the textile bag under water and the law of water barrier. The simulation analysis focuses on the water resistance effect and flow field distribution characteristics of the textile bag in the water passage under the condition of low flow rate and low pressure, as well as the stability and self-deformation characteristics of the textile bag under the condition of high flow rate and high pressure. The accuracy of the limit resistance to water pressure of the textile bag obtained from theoretical analysis is verified. The results show that the theoretical analysis is consistent with the simulation results. The textile bag can realize the fast controllable plugging of the large water passage of moving water within the limit of the antihydraulic stress.

Safety Analysis of the Temporary Dam Body of Concrete Faced Rockfill Dam during Construction Period

2011 ◽  
Vol 255-260 ◽  
pp. 3676-3681 ◽  
Author(s):  
Xiao Chun Lu ◽  
Bin Tian ◽  
Suo Zhang
Keyword(s):  
Numerical Simulation ◽  
Flood Control ◽  
Analysis Method ◽  
Nonlinear Fem ◽  
Seepage Field ◽  
Construction Period ◽  
Rockfill Dam ◽  
Practical Project ◽  
The Stability ◽  
Effective Analysis

Concrete faced Rockfill dam (CFRD) is a safe and economical dam type in hydraulic engineering. The temporary dam body for flood control during construction period is usually used for CFRD, so the safety of temporary dam body during construction period is very important. Based on numerical simulation of the seepage field of the temporary dam body of CFRD using nonlinear FEM (Finite Element Method) under the action of flood of the river during construction period, the stability of the dam slope is studied. The effectiveness and applicability of the method introduced is certified through computation in the study on the practical project. The paper provides an effective analysis method for the study on the stability of dam slope of the temporary dam body of CFRD for flood control during construction period.

Numerical Simulation Analysis on Stability of Coal Pillar of Empty Mine Goaf in North of Shanxi Province

2013 ◽  
Vol 470 ◽  
pp. 205-210
Author(s):  
Hao Tang ◽  
Zi Guang He ◽  
Hai Bo Lian
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Coal Pillar ◽  
Shanxi Province ◽  
Analysis Model ◽  
Term Stability ◽  
Long Term Stability ◽  
The Law ◽  
The Stability

The analysis model of coal pillar of a empty mine goaf in north of Shanxi province was constructed and the process of coal pillar from formation to weathering was simulated through the application of software of FLAC3D in this article. The stressstrain and the law of plasticity transformation of coal pillar from formation to weathering were analyzed and the long-term stability of coal pillar was forecasted. The result showed that the stability of coal pillar was bad for excessive excavated and weathering and the coal pillar will be broken easier for pressure and shear.

scholarly journals Study of the stability of tunnel construction based on double-heading advance construction method

2020 ◽  
Vol 12 (1) ◽  
pp. 168781401989696 ◽  
Author(s):  
Zhanping Song ◽  
Guilin Shi ◽  
Baoyun Zhao ◽  
Keming Zhao ◽  
Junbao Wang
Keyword(s):  
Numerical Simulation ◽  
Construction Method ◽  
Field Monitoring ◽  
Surrounding Rock ◽  
Tunnel Construction ◽  
Successful Implementation ◽  
Simulation Results ◽  
The Stability ◽  
Sand Stratum ◽  
The Right

The deformation and significant settlement of surrounding rock often occur during tunnel construction with the condition of abundant water and weak cementing sand. In order to study the construction method and stability under such soft stratum, this article takes Taoshuping tunnel as the engineering background and puts forward a new tunnel construction method—double-heading advance construction method by comparing the advantages and disadvantages of various traditional construction schemes. The numerical simulation of tunnel construction process using this method is carried out to illustrate the rationality and feasibility of the method. The conclusions are drawn by comparing the numerical simulation results with the field monitoring data analysis. The numerical simulation results show that the maximum settlement value caused by excavation construction is in the parts 5 and 6 of the upper half-section and the part 7 of the central section. The settlement values of parts 5, 6, and 7 accounted for 32.4%, 24.3%, and 18.9% of the total settlement values, respectively. So, the supporting measures for double-heading advance excavation construction of these three parts should be strengthened properly. The stress of the right hance changes greatly before and after the demolition of temporary support. The maximum positive value of stress is 23 kPa and the maximum negative value of stress is −32 kPa. Therefore, the length of temporary bracing should be strictly controlled during construction and the monitoring of the right hance area should be strengthened. Furthermore, it is necessary to strengthen the supporting measures and monitoring in the right spandrel area as the surrounding rock pressure in the right spandrel area is higher than the left spandrel area. The optimum excavation height of the upper half-section in Taoshuping tunnel is determined to be 5.4 m and the reasonable excavation distance between parts 1 and 5 is determined to be 25–30 m by parameter optimization. Finally, the variation law of numerical simulation and field monitoring results is consistent, which shows that the double-heading advance construction method has a better effect on the stability control of surrounding rock, and the rationality and feasibility of this method are validated effectively. Therefore, the double-heading advance method is suitable for tunnel construction in the sand stratum with rich water and weak cementation, and the successful implementation of this method in Taoshuping tunnel also provides a reference for subsequent tunnel construction in the sand stratum with rich water and weak cementation.

Numerical Simulation Analysis of Tailings Dam Heightening Expansion Stability

2014 ◽  
Vol 670-671 ◽  
pp. 1079-1082
Author(s):  
He Bing
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Operating Mode ◽  
Tailings Dam ◽  
Regulatory Requirements ◽  
Stability Coefficient ◽  
Standard Value ◽  
Dam Stability ◽  
The Stability ◽  
Maximum Limit

Xinchang tailings dam is used as an object and the software named Slide is utilized to operate numerical simulation, and then the three conditions (normal operating mode, flood conditions, the special conditions) of tailings dam are analyzed to determine the stability. The conclusions are as follows: tailings dam have been built to 80m height, both to meet regulatory requirements, so the dam is stable; but if continue to increase the height to 85m, tailings dam stability coefficient reduced to special conditions 1.032, less than the standard value 1.05, does not meet the national regulatory requirements, the maximum limit of a height of about 80m.

Numerical Simulation Analysis of the Nanyangpo Coal Mine Anchor Support Method

2012 ◽  
Vol 619 ◽  
pp. 231-238
Author(s):  
Mei Chang Zhang ◽  
Peng Cheng Fei ◽  
De Long Zou
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Nursing Program ◽  
Load Carrying ◽  
Deformation Law ◽  
The Stability ◽  
Surrounding Rock Deformation ◽  
Bolt Support

The bolt support is important to ensure the stability of surrounding rock. Of Nan Yangpo mines as the research background. The application of numerical simulation software FLAC3D mine deep Bolt bolt support after the surrounding rock deformation law of the numerical simulation, Comparison and analysis of rock displacement and plastic zone under the support program changes. The results show that, The third bolt support nursing program, Significantly improve the strength and load carrying capacity of the surrounding rock, Effectively control the damage of the deep tunnel deformation that can control the roof of 4101 the return airway and two to help the stability.

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