scholarly journals Characteristic parameters’ optimization based on contact pressure of sealing gasket for segmental joints

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402094336
Author(s):  
Zhang Junwei ◽  
Chen Yunyao ◽  
Feng Qianke

The aim of this study is to optimize the characteristic parameters of the segmental joints based on the contact pressure of sealing gasket. The design status of shield tunnel segment joint sealing gasket material, cross-section type, and holes arrangement through statistical data are first analyzed using the numerical simulation method. The result of this study indicates that the linear regression analysis of the outer contour parameters of the gasket was carried out using the bottom edge length of the gasket as the control variable in accordance with the statistical samples, and the influence of geometric parameters on the waterproofing design of sealing gasket is analyzed by numerical simulation from the aspects of the number of closed holes, the shape of closed holes, and the change of the opening rate in different parts. Characteristic parameters optimization of rubber hardness parameters on waterproof design of sealing gaskets have been completed on the contact pressure of sealing gasket for segmental joints. It provided some references for the design, production, processing, and quality inspection of shield tunnel gasket in the future.

2021 ◽  
Author(s):  
Ruijie Huang ◽  
Chenji Wei ◽  
Baozhu Li ◽  
Jian Yang ◽  
Suwei Wu ◽  
...  

Abstract Production prediction continues to play an increasingly significant role in reservoir development adjustment and optimization, especially in water-alternating-gas (WAG) flooding. As artificial intelligence continues to develop, data-driven machine learning method can establish a robust model based on massive data to clarify development risks and challenges, predict development dynamic characteristics in advance. This study gathers over 15 years actual data from targeted carbonate reservoir and establishes a robust Long Short-Term Memory (LSTM) neural network prediction model based on correlation analysis, data cleaning, feature variables selection, hyper-parameters optimization and model evaluation to forecast oil production, gas-oil ratio (GOR), and water cut (WC) of WAG flooding. In comparison to traditional reservoir numerical simulation (RNS), LSTM neural networks have a huge advantage in terms of computational efficiency and prediction accuracy. The calculation time of LSTM method is 864% less than reservoir numerical simulation method, while prediction error of LSTM method is 261% less than RNS method. We classify producers into three types based on the prediction results and propose optimization measures aimed at the risks and challenges they faced. Field implementation indicates promising outcome with better reservoir support, lower GOR, lower WC, and stabler oil production. This study provides a novel direction for application of artificial intelligence in WAG flooding development and optimization.


2021 ◽  
Vol 9 (6) ◽  
pp. 680
Author(s):  
Hui Li ◽  
Yan Feng ◽  
Muk Chen Ong ◽  
Xin Zhao ◽  
Li Zhou

Selecting an optimal bow configuration is critical to the preliminary design of polar ships. This paper proposes an approach to determine the optimal bow of polar ships based on present numerical simulation and available published experimental studies. Unlike conventional methods, the present approach integrates both ice resistance and calm-water resistance with the navigating time. A numerical simulation method of an icebreaking vessel going straight ahead in level ice is developed using SPH (smoothed particle hydrodynamics) numerical technique of LS-DYNA. The present numerical results for the ice resistance in level ice are in satisfactory agreement with the available published experimental data. The bow configurations with superior icebreaking capability are obtained by analyzing the sensitivities due to the buttock angle γ, the frame angle β and the waterline angle α. The calm-water resistance is calculated using FVM (finite volume method). Finally, an overall resistance index devised from the ship resistance in ice/water weighted by their corresponding weighted navigation time is proposed. The present approach can be used for evaluating the integrated resistance performance of the polar ships operating in both a water route and ice route.


2017 ◽  
Vol 322 ◽  
pp. 301-312 ◽  
Author(s):  
Susumu Yamashita ◽  
Takuya Ina ◽  
Yasuhiro Idomura ◽  
Hiroyuki Yoshida

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yijie Shi ◽  
Pengfei Wang ◽  
Ronghua Liu ◽  
Xuanhao Tan ◽  
Wen Zhang

Coalbed water injection is the most basic and effective dust-proof technology in the coal mining face. To understand the influence of coalbed water injection process parameters and coalbed characteristic parameters on coal wetting radius, this paper uses Fluent computational fluid dynamics software to systematically study the seepage process of coalbed water injection under different process parameters and coalbed characteristic parameters, calculation results of which are applied to engineering practice. The results show that the numerical simulation can help to predict the wetness range of coalbed water injection, and the results can provide guidance for the onsite design of coalbed water injection process parameters. The effect of dust reduction applied to onsite coalbed water injection is significant, with the average dust reduction rates during coal cutting and support moving being 67.85% and 46.07%, respectively, which effectively reduces the dust concentration on the working face and improves the working environment.


2020 ◽  
Vol 12 (1) ◽  
pp. 703-717
Author(s):  
Yin Wei ◽  
Wang Jiaqi ◽  
Bai Xiaomin ◽  
Sun Wenjie ◽  
Zhou Zheyuan

AbstractThis article analyzes the technical difficulties in full-section backfill mining and briefly introduces the technical principle and advantages of backfilling combined with caving fully mechanized mining (BCCFM). To reveal the strata behavior law of the BCCFM workface, this work establishes a three-dimensional numerical model and designs a simulation method by dynamically updating the modulus parameter of the filling body. By the analysis of numerical simulation, the following conclusions about strata behavior of the BCCFM workface were drawn. (1) The strata behavior of the BCCFM workface shows significant nonsymmetrical characteristics, and the pressure in the caving section is higher than that in the backfilling section. φ has the greatest influence on the backfilling section and the least influence on the caving section. C has a significant influence on the range of abutment pressure in the backfilling section. (2) There exits the transition area with strong mine pressure of the BCCFM workface. φ and C have significant effect on the degree of pressure concentration but little effect on the influence range of strong mine pressure in the transition area. (3) Under different conditions, the influence range of strong mine pressure is all less than 6 m. This article puts forward a control strategy of mine pressure in the transition area, which is appropriately improving the strength of the transition hydraulic support within the influence range (6 m) in the transition area according to the pressure concentration coefficient. The field measurement value of Ji15-31010 workface was consistent with numerical simulation, which verifies the reliability of control strategy of the BCCFM workface.


2021 ◽  
Vol 11 (6) ◽  
pp. 2551
Author(s):  
Hyobum Lee ◽  
Hangseok Choi ◽  
Soon-Wook Choi ◽  
Soo-Ho Chang ◽  
Tae-Ho Kang ◽  
...  

This study demonstrates a three-dimensional numerical simulation of earth pressure balance (EPB) shield tunnelling using a coupled discrete element method (DEM) and a finite difference method (FDM). The analysis adopted the actual size of a spoke-type EPB shield tunnel boring machine (TBM) consisting of a cutter head with cutting tools, working chamber, screw conveyor, and shield. For the coupled model to reproduce the in situ ground condition, the ground formation was generated partially using the DEM (for the limited domain influenced by excavation), with the rest of the domain being composed of FDM grids. In the DEM domain, contact parameters of particles were calibrated via a series of large-scale triaxial test analyses. The model simulated tunnelling as the TBM operational conditions were controlled. The penetration rate and the rotational speed of the screw conveyor were automatically adjusted as the TBM advanced to prevent the generation of excessive or insufficient torque, thrust force, or chamber pressure. Accordingly, these parameters were maintained consistently around their set operational ranges during excavation. The simulation results show that the proposed numerical model based on DEM–FDM coupling could reasonably simulate EPB driving while considering the TBM operational conditions.


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