scholarly journals Research on Anchor Cable and C-Shaped Tube Support Method in Deep Layers Roadway, Experimental Study, and Numerical Simulation

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Renliang Shan ◽  
Shupeng Zhang ◽  
Shengchao Xiao ◽  
Junqi Liang
Keyword(s):  
Numerical Simulation ◽  
Design Method ◽  
Soft Rock ◽  
Shear Resistance ◽  
Rock Properties ◽  
Tube Length ◽  
Support Design ◽  
Anchor Cable ◽  
Rock Formations ◽  
Shaped Tube

In roadways with high ground stress or burial depths, the joints distributed within rock formations are subject to complex stresses and interlayer misalignments frequently. Rock bolts and cable bolts anchored in the rock formations are subject to tensile and shear forces. Most of the bolts used in roadway engineering are local anchored, resulting in insufficient shear strength at the bolt free end close to roadway surface and increasing bolts breaking. The anchor cable and C-shaped tube (ACC) is a highly prestressed cable bolt that can withstand high shear force in its free end. This paper examines the effect of the relationship between C-shaped tube length and joint location on the shear resistance of ACC by double shear tests. To fully exploit the ACC’s shear resistance, the C-shaped tube ends should be at least 30 cm beyond the joint. The effect of preload and concrete spray thicknesses on roadway deformation and plastic zone is investigated by numerical simulation. Results show that ACC and concrete spraying layer can form a stable extruded arch structure, so that the broken and soft rock within the loosen zone is in three-dimensional-stress state, effectively improving surrounding rock properties and controlling its deformation size. Based on these results, the ACC support design method is proposed.

scholarly journals Research on Full-Section Anchor Cable and C-Shaped Tube Support System of Deep Layer Roadway

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Renliang Shan ◽  
Shupeng Zhang ◽  
Pengcheng Huang ◽  
Weijun Liu
Keyword(s):  
Support System ◽  
Surface Displacement ◽  
Field Tests ◽  
Soft Rock ◽  
Shear Resistance ◽  
Tectonic Stress ◽  
Anchor Cable ◽  
Shaped Tube ◽  
Roadway Deformation ◽  
Prestressed Anchor

Deep roadway deformation due to soft rock, rock dip, and horizontal tectonic stress is uneven and asymmetrical primarily in large loose zones. Traditional anchor support is influenced by the yield strength and shear strength of the anchors and has a limited prestress capacity or shear resistance. When the roadway roof is laminated rock or when the roadway passes through layered rock or rock interfaces, interlayer sliding commonly occurs, which can easily lead to anchor cables being sheared off. The tape tunnel in the Zhengling Mine passes through several rock strata and requires anchors to achieve a high shear resistance and prestress. To solve these problems, an anchor cable and C-shaped tube that can bear lateral shear forces were developed, and a full-section anchor cable and C-shaped tube support system were created based on extruded arch theory. Numerical results from FLAC3D show that the new scheme effectively controls surface convergence and plastic zone extension. Field tests have demonstrated that the amount of surface displacement was at least 42% smaller in the new support scheme. The extruded arch formed by the highly prestressed anchor cable and concrete spray layer can effectively control the bulking load within the loose zone, and the ACC effectively resists interlayer shear.

scholarly journals Study on the Mechanical Behavior of Double Primary Support of Soft Rock Tunnel under High Ground Stresses and Large Deformation

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhe Liu
Keyword(s):  
Mechanical Behavior ◽  
Large Deformation ◽  
Design Method ◽  
Characteristic Curve ◽  
Soft Rock ◽  
Support Design ◽  
Deformation Amount ◽  
Secondary Lining ◽  
Rock Tunnels ◽  
Primary Support

Double primary support structures could effectively solve the problem of large deformation of surrounding rock for soft rock tunnels. However, the mechanical behavior of this new support structure is still incomplete, and the design method should be revised. Based on the theory of energy conversion, this paper analyzes the support characteristic curve of double primary support and puts forward the dynamic design method of double primary support. Considering that the secondary lining can be set after monitoring the deformation amount and deformation rate of the first primary support, its support parameters can be dynamically adjusted according to the actual situation. By applying the double primary support design method in the Maoxian tunnel of Chenglan Railway, the field monitoring results show that the double primary support has a significant effect on the energy release of surrounding rocks, greatly reducing the load acting on the secondary lining and ensuring the safety and reliability of the tunnel structure.

scholarly journals Construction Monitoring and Numerical Simulation of Water-Rich Tuff Soft Rock Tunnel

2020 ◽  
Vol 455 ◽  
pp. 012163
Author(s):  
Fangliang Chen ◽  
Kaihua Zeng ◽  
Xuejun Li ◽  
Manqing Xu ◽  
Hongtao Dai
Keyword(s):  
Numerical Simulation ◽  
Soft Rock ◽  
Construction Monitoring ◽  
Rock Tunnel

Research on NX-Based Progressive Die Design

2012 ◽  
Vol 602-604 ◽  
pp. 1818-1821
Author(s):  
Jun Liu ◽  
Cong Dong Ji
Keyword(s):  
Design Method ◽  
Equivalent Stress ◽  
Equivalent Strain ◽  
Die Design ◽  
Support Design ◽  
Stress Resilience ◽  
Progressive Die ◽  
Key Technology ◽  
Product Manufacturing ◽  
Progressive Die Design

Progressive die has been widely used in product manufacturing field. This paper proposed a NX-based computer server support design method. The equivalent stress, resilience, equivalent strain, attenuation, and forming were analyzed in detail. The key technology of confirming blank dimension and stock layout of server support were explicated clearly.

Calculation and Design Method Study of the Coil-Wound Heat Exchanger

2014 ◽  
Vol 1008-1009 ◽  
pp. 850-860 ◽  
Author(s):  
Zhou Wei Zhang ◽  
Jia Xing Xue ◽  
Ya Hong Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchanger ◽  
Design Method ◽  
Fluid Velocity ◽  
Exchange Process ◽  
Three Dimensional ◽  
Simulation Method ◽  
Physical Parameters ◽  
Numerical Result

A calculation method for counter-current type coil-wound heat exchanger is presented for heat exchange process. The numerical simulation method is applied to determine the basic physical parameters of wound bundles. By controlling the inlet fluid velocity varying in coil-wound heat exchanger to program and calculate the iterative process. The calculation data is analyzed by comparison of numerical result and the unit three dimensional pipe bundle model was built. Studies show that the introduction of numerical simulation can simplify the pipe winding process and accelerate the calculation and design of overall configuration in coil-wound heat exchanger. This method can be applied to the physical modeling and heat transfer calculation of pipe bundles in coil wound heat exchanger, program to calculate the complex heat transfer changing with velocity and other parameters, and optimize the overall design and calculation of spiral bundles.

Correlation of Soft Rock Properties

2019 ◽  
pp. 407-421
Author(s):  
Milton Assis Kanji ◽  
Marcio Leão
Keyword(s):  
Soft Rock ◽  
Rock Properties

scholarly journals Research on Parametric Design of Hydraulic Retarder Based on Multi-Field Coupling of Heat, Fluid and Solid

2015 ◽  
Vol 9 (1) ◽  
pp. 58-64 ◽  
Author(s):  
Kuiyang Wang ◽  
Jinhua Tang ◽  
Guoqing Li
Keyword(s):  
Numerical Simulation ◽  
Parametric Design ◽  
Design Method ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Field Coupling ◽  
Sequential Coupling ◽  
Fluid Coupling ◽  
Hydraulic Retarder

In order to optimize the design method and improve the performance of hydraulic retarder, the numerical simulation of multi-field coupling of heat, fluid and solid is carried out to hydraulic retarder, based on the numerical computation and algorithm of heat-fluid coupling and fluid-solid coupling. The computation models of heat-fluid coupling and fluid-solid coupling of hydraulic retarder are created. The three dimensional model of hydraulic retarder is established based on CATIA software, and the whole flow passage model of hydraulic retarder is extracted on the basis of the three dimensional model established. Based on the CFD calculation and the finite element numerical simulation, the temperature field, stress field, deformation and stress state are analysised to hydraulic retarder in the state of whole filling when the rotate speed is 1600 r/min. In consideration of rotating centrifugal force, thermal stress and air exciting vibration force of blade surface, by using the sequential coupling method, the flow field characteristics of hydraulic retarder and dynamic characteristics of blade structure are analysised and researched based on multi-field coupling of heat, fluid and solid. These provide the theoretical foundation and references for parametric design of hydraulic retarder.

scholarly journals Numerical Simulation of Diffusion Absorption Refrigerator

2021 ◽  
Vol 233 ◽  
pp. 01044
Author(s):  
Guoyan Zhang ◽  
Shengyong Liu ◽  
Jie Lu ◽  
Jiong Wang ◽  
Yongtao Ma
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Gas Phase ◽  
Radial Direction ◽  
Tube Length ◽  
Lifting Capacity ◽  
Fluent Software ◽  
Lower Temperature ◽  
Absorption Refrigerator ◽  
Diffusion Absorption

Based on Fluent software, a mathematical model of thermosyphon pump is established and numerical simulation is carried out to study the influence of riser tube length, tube diameter and immersion ratio on liquid lifting capacity and efficiency. The results showed that: the liquid lifting volume increased with the increase of immersion ratio, whereas the lifting efficiency showed a trend of increasing followed by decreasing. The highest lifting efficiency for a 340mm long, 6mm diameter riser achieved when the immersion ratio is 0.35. With the increasing of the height in riser, the velocity of the gas phase close to the wall in the thermosyphon pump was higher than the velocity along the radial direction. In order to enhance fluid interchange, corners of the refrigeration box were designed to be arc-shaped with a higher corner speed and lower temperature.

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