scholarly journals Numerical Simulation on the Response of Adjacent Underground Pipelines to Super Shallow Buried Large Span Double-Arch Tunnel Excavation

2022 ◽  
Vol 12 (2) ◽  
pp. 621
Author(s):  
Jianxiu Wang ◽  
Ansheng Cao ◽  
Zhao Wu ◽  
Zhipeng Sun ◽  
Xiao Lin ◽  
...  

The excavation of a shallow buried tunnel may cause stress redistribution in surrounding rock, and cause deformation, damage, and even destruction of adjacent underground pipelines. The land part of the Haicang undersea tunnel in Xiamen of China was a super shallow buried large span double-arch tunnel. Its construction was restricted by both underground excavation safe and adjacent pipeline protection. Multiple groups of working conditions were designed considering the relative position of pipe and tunnel, pipeline and tunnel construction parameters. Numerical simulation was used to study the influence of pipeline horizontal distance, buried depth, pipeline diameter, pipeline wall thickness, pipeline shape, pipeline material and excavation method on the response of adjacent underground pipelines. The results show that the relative position of pipe and tunnel, and the construction method of the double-arch tunnel have a great influence on pipeline deformation. Pipeline material, pipeline diameter and excavation method have a great influence on pipeline stress. The construction method was the key factor affecting the stress and deformation of the pipeline. The three-step reserved core soil method can effectively control the stress and deformation of underground pipelines. The research results can provide a reference for similar projects.

2011 ◽  
Vol 243-249 ◽  
pp. 2065-2070
Author(s):  
Run Lin Yang ◽  
Juan Juan Wang ◽  
Hai Cheng Zhou

It is necessary to study the mechanic behavior of underground pipelines during the excavation of the foundation pit, because the excavation will inevitably endanger the nearby underground pipelines. Three factors include the depth of underground pipelines, the distance from the pipeline to the foundation pit and ground load are considered to conform comparative analysis, in order to study the variaty on the stress and deformation of the underground pipelines. The foundation surporting type and the soil layer distribution are also considered during the numerical simulation. The results show that the distance between pipeline and foundation has more influence on the underground pipelines than other two factors, the damage most likely occurred in the bottom right in the pipeline near the foundation pit.


2013 ◽  
Vol 788 ◽  
pp. 534-537 ◽  
Author(s):  
Zhen Xing Li

Different construction schemes in the same construction method have great influence on structure mechanics of grid structure, which is very important for the security and stability in large-span space grid structure. So in order to guarantee the quality and safety of the structure during construction, the selection of construction scheme is particularly important. In this paper, the following practical engineering is adopted to discuss characteristics of different construction schemes in large-span space grid structure and provide a reference for what construction scheme should be selected in the installation of similar space grid structures.


Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1737
Author(s):  
Milan Banić ◽  
Dušan Stamenković ◽  
Aleksandar Miltenović ◽  
Dragan Jovanović ◽  
Milan Tica

The selection of a rubber compound has a determining influence on the final characteristics of rubber-metal springs. Therefore, the correct selection of a rubber compound is a key factor for development of rubber-metal vibration isolation springs with required characteristics. The procedure for the selection of the rubber compound for vibration isolation of rubber-metal springs has been proposed, so that the rubber-metal elements have the necessary characteristics, especially in terms of deflection. The procedure is based on numerical simulation of spring deflection with Bergström-Boyce constitutive model in virtual experiment, with a goal to determine which parameters of the constitutive model will lead to spring required deflection. The procedure was verified by case study defined to select rubber compound for a rubber–metal spring used in railway engineering.


Author(s):  
Hairui Wang ◽  
Chunfang Guo ◽  
Yujie Li ◽  
Yahua Liu ◽  
Minjie Wang ◽  
...  

With the advantage of high adaptability, Miura-origami structure with curvature shows various engineering applications such as a sandwich between two stiff facings with curvature requirements and structural support to form a circular tube. In this research, a forming method of polymer circular tube with single-curved surface origami expressed by five parameters was established and its corresponding theory was solved considering forming rationality in actual manufacturing. The components of circular tube were fabricated by the vacuum forming process and then spliced together. We conducted numerical simulation to analyze the structural performance of the tube with five parameters and shown that these parameters have a great influence on energy absorbed performance. Finally, a male mold of a part with Arc Miura-origami structure was designed and fabricated. The parts with Arc Miura-origami were manufactured using vacuum forming process and then spliced and bonded together into a two-layer tube. This research may provide a method to design and fabricate Miura-origami structure with high efficiency and quality.


2014 ◽  
Vol 490-491 ◽  
pp. 594-599
Author(s):  
Fan Ling Meng ◽  
Ai Guo Liu

Automatic MIG was adopted to weld Inconel 625 alloy on 20 G Membrane Waterwall, which can improve the capacities of high temperature corrosion resistance and wear resistance. To study the influence of Membrane Waterwall surface welding sequences on residual stress and residual deformation, this paper utilized finite element software ABAQUS and segmented moving heat source model to simulate the sequence welding, balanced welding from the middle to sides, balanced welding from sides to the middle, balanced skip welding from middle to sides and balanced skip welding from sides to the middle and studied their residual stresses and deformations. The simulation results indicated that there was a great influence of welding sequences on the residual stress and deformation. The optimal welding sequence was balanced skip welding from middle to sides and balanced skip welding from sides to the middle, which could change the stress distribution, decrease the welding residual stress by 17%, realize the even deformation of the whole welding section and decrease the bending deformation by 50%.


2014 ◽  
Vol 488-489 ◽  
pp. 1047-1051
Author(s):  
Qing Qian Zheng ◽  
Bin Yang ◽  
Ning Chen ◽  
Hui Min Yang ◽  
Min Hu

In this paper, the finite method is applied and ABAQUS software is used, the vortex flow field is loaded as boundary condition of wraps. The stress and deformation in scroll under the action of gas pressure, temperature load and both of them is analyzed, the stress distribution and deformation of wraps in different shaft rotation angles is discussed, the stress distribution and deformation discipline of wraps are also respectively obtained. The results show that the overall stress and deformation in scroll are the largest when compression chamber is moving near the vent position and the thermal deformation is the main factor of affecting the overall deformation of scroll.


Author(s):  
Qiao Luo ◽  
Xiaobing Zhang

Purpose – In engineering applications, gas-solid two-phase reaction flow with multi-moving boundaries is a common phenomenon. The launch process of multiple projectiles is a typical example. The flow of adjacent powder chambers is coupled by projectile’s motion. The purpose of this paper is to study this flow by numerical simulation. Design/methodology/approach – A one-dimensional two-phase reaction flow model and MacCormack difference scheme are implemented in a computational code, and the code is used to simulate the launch process of a system of multiple projectiles. For different launching rates and loading conditions, the simulated results of the launch process of three projectiles are obtained and discussed. Findings – At low launching rates, projectiles fired earlier in the series have little effect on the launch processes of projectiles fired later. However, at higher launching rates, the projectiles fired first have a great influence on the launch processes of projectiles fired later. As the launching rate increases, the maximum breech pressure for the later projectiles increases. Although the muzzle velocities increase initially, they reach a maximum at some launching rate, and then decrease rapidly. The muzzle velocities and maximum breech pressures of the three projectiles have an approximate linear relationship with the charge weight, propellant web size and chamber volume. Originality/value – This paper presents a prediction tool to understand the physical phenomenon of the gas-solid two-phase reaction flow with multi-moving boundaries, and can be used as a research tool for future interior ballistics studies of launch system of multiple projectiles.


2014 ◽  
Vol 501-504 ◽  
pp. 248-253
Author(s):  
Liu Yong Cheng ◽  
Shan Xiong Chen ◽  
Xi Chang Xu ◽  
Xiao Jie Chu ◽  
Tong Bing Lei

The regular pattern of the lateral friction transmission is one of the most critical influences on the ultimate uplift bearing capacity. The pile foundation in the incline under the pulling force has a wide variety of characteristics which is different with the normal pile. Numerical simulation is done by the use of FLAC3D in this paper. The regular pattern of the lateral friction transmission of the pile in the incline under the pulling force is studied. And the influence factors on the lateral friction transmission such as the slope gradient, the length and location of piles are discussed. The results show that the incline has a great influence on the lateral friction transmission. The lateral friction which is away from the incline-side is about 30% to 50% bigger than the incline-side. The slope gradient and the location of piles all have a great influence on the lateral friction transmission.


2011 ◽  
Vol 339 ◽  
pp. 624-629
Author(s):  
Lian Cheng Ren ◽  
Zheng Liang ◽  
Jiang Meng ◽  
Lin Yang ◽  
Jia Lin Tian

On the base of numerical simulation and theoretical analysis, the flow field of a conventional single-tangential-inlet Hydrocyclone and a newly put forward axial-symmetry double-tangential-inlet hydrocyclone were contrasted. The study shows that the inlet structure of the Hydrocylone has a great influence on the radial velocity of the flow field in the hydrocyclone and that the radial velocity in the hydrocyclone with single-tangential-inlet is not symmetry about the axis of the hydrocyclone; and on the other hand the radial velocity in the hydrocyclone with axial-symmetry double-tangential-inlet is symmetry about the axis of the hydrocyclone. The magnitude of the radial velocity of the flow in the hydrocyclone with single-tangential-inlet is greater than that in the hydrocyclone with axial-symmetry double-tangential-inlet hydrocyclone, which means the hydrocyclone with axial-symmetry double-tangential-inlet has greater capability than the rival one with single-tangential inlet. The symmetry about the axis of the hydrocyclone of the radial velocity means the radial velocities in the place where the radio is the same are constant, which means the hydrocyclone has a great separation efficiency. The conclusion is that changing the conventional hydrocyclone into the one with axial-symmetry double-tangential-inlet structure can offer greater separation capability and efficiency.


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