scholarly journals Experimental and Numerical Study on a Grouting Diffusion Model of a Single Rough Fracture in Rock Mass

2020 ◽  
Vol 10 (20) ◽  
pp. 7041
Author(s):  
Wenqi Ding ◽  
Chao Duan ◽  
Qingzhao Zhang
Keyword(s):  
Rock Mass ◽  
Diffusion Process ◽  
Diffusion Model ◽  
Numerical Study ◽  
Structural Characteristics ◽  
Analytical Formula ◽  
Diffusion Experiment ◽  
Cement Slurry ◽  
Temporal And Spatial Distribution ◽  
Rough Fracture

Grouting reinforcement is an important method used to solve problems encountered during tunnel construction, such as collapse and water gushing. The grouting diffusion process is greatly influenced by the structural characteristics of the fractures in a rock mass. First, an analytical grouting diffusion model of a single rough fracture under constant-pressure control is established based on the constitutive equation of a Bingham fluid. Second, the “quasi-elliptical” grouting diffusion pattern under the influence of roughness is revealed through a grouting diffusion experiment, which is conducted with an independently developed visualized testing apparatus. Furthermore, the analytical formula of roughness-corrected grouting diffusion characterized by the saw tooth density is established. Finally, an elaborate numerical simulation of the diffusion process of cement slurry (Bingham flow type) in a single rough fracture is carried out by introducing the Bingham–Papanastasiou rheological model. The temporal and spatial distribution characteristics of the velocity field and pressure field during the grouting diffusion process are analyzed as well. Moreover, the method and range of the roughness correction factor in the analytical grouting diffusion model are proposed based on the fracture roughness unit.

Numerical Study of Zonal Disintegration within a Rock Mass around a Deep Excavated Tunnel

2012 ◽  
Vol 12 (4) ◽  
pp. 471-483 ◽  
Author(s):  
Yujun Zuo ◽  
Tao Xu ◽  
Yongbin Zhang ◽  
Yiping Zhang ◽  
Shucai Li ◽  
...  
Keyword(s):  
Rock Mass ◽  
Numerical Study ◽  
Zonal Disintegration

Computation of Madalines' Sensitivity to Input and Weight Perturbations

2006 ◽  
Vol 18 (11) ◽  
pp. 2854-2877 ◽  
Author(s):  
Yingfeng Wang ◽  
Xiaoqin Zeng ◽  
Daniel So Yeung ◽  
Zhihang Peng
Keyword(s):  
Probability Theory ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
Analytical Formula ◽  
Single Neurons ◽  
Important Measure ◽  
Simulation Results ◽  
Theoretical Results ◽  
Good Agreement

The sensitivity of a neural network's output to its input and weight perturbations is an important measure for evaluating the network's performance. In this letter, we propose an approach to quantify the sensitivity of Madalines. The sensitivity is defined as the probability of output deviation due to input and weight perturbations with respect to overall input patterns. Based on the structural characteristics of Madalines, a bottomup strategy is followed, along which the sensitivity of single neurons, that is, Adalines, is considered first and then the sensitivity of the entire Madaline network. Bymeans of probability theory, an analytical formula is derived for the calculation of Adalines' sensitivity, and an algorithm is designed for the computation of Madalines' sensitivity. Computer simulations are run to verify the effectiveness of the formula and algorithm. The simulation results are in good agreement with the theoretical results.

Numerical Study on Influence of Joint Characters on Rock Mechanical Parameters

2011 ◽  
Vol 201-203 ◽  
pp. 2909-2912
Author(s):  
Yan Feng Feng ◽  
Tian Hong Yang ◽  
Hua Wei ◽  
Hua Guo Gao ◽  
Jiu Hong Wei
Keyword(s):  
Rock Mass ◽  
Compression Strength ◽  
Numerical Study ◽  
Process Analysis ◽  
Failure Process ◽  
Deformation Modulus ◽  
Rock Joints ◽  
Structured Surfaces ◽  
Trace Length ◽  
The Impact

Rock mass is the syntheses composed of kinds of structure and structured surfaces. The joint characters is influencing and controlling the rock mass strength, deformation characteristics and rock mass engineering instability failure in a great degree. Through using the RFPA2D software, which is a kind of material failure process analysis numerical methods based on finite element stress analysis and statistical damage theory, the uniaxial compression tests on numerical model are carried, the impact of the trace length of rock joints and the fault throws on rock mechanics parameters are studied. The results showed that with the gradual increase of trace length,compression strength decreased gradually and its rate of variation getting smaller and smaller, the deformation modulus decreased but the rate of variation larger and larger; with the fault throws increasing, the compression strength first increases and then decreases, when the fault throw is equal to the trace length, the deformation modulus is the largest. When the joint trace length is less than the fault throw, the rate of the deformation modulus is greater than that of trace length, but the deformation modulus was not of regular change.

Numerical Investigation of the Identifiability of Elastomer Mechanical Properties by Nano-Indentation and Shape-Manifold Approach

2021 ◽  
Author(s):  
Oumaima Ezzaamari ◽  
Guénhaël Le Quilliec ◽  
Florian Lacroix ◽  
Stéphane Méo
Keyword(s):  
Numerical Study ◽  
Interpolation Method ◽  
Structural Characteristics ◽  
Numerical Approach ◽  
Kriging Interpolation ◽  
Nano Indentation ◽  
Kriging Interpolation Method ◽  
Elastomeric Materials ◽  
Hyper Elastic ◽  
Characterization Test

ABSTRACT Various research is covering instrumented nano-indentation in the literature. However, studies on this characterization test remain limited when it comes to the local mechanical behavior of elastomeric materials. The application of nano-indentation on these materials is a difficult task given their complex mechanical and structural characteristics. We try to overcome these experimental limitations and find an effective numerical approach for local mechanical characterization of hyper-elastic materials. For such needs, we carried out a numerical study based on model reduction and shape manifold approach to investigate the parameters identification of different hyper-elastic constitutive laws by using instrumented indentation. Similarly, we studied the influence of the indenter geometry, the friction coefficient variation, and finally the indented material height effect. To this end, we constructed a reduced order model through a design of experiments by proper orthogonal decomposition combined with the kriging interpolation method.

Modeling two-dimensional technology diffusion process under dynamic adoption rate

2019 ◽  
Vol 14 (3) ◽  
pp. 717-737 ◽  
Author(s):  
P.K. Kapur ◽  
Saurabh Panwar ◽  
Ompal Singh
Keyword(s):  
Diffusion Process ◽  
Diffusion Model ◽  
Change Point ◽  
Price Change ◽  
Dynamic State ◽  
Technological Innovations ◽  
Two Dimensional ◽  
Content Type ◽  
Adoption Rate ◽  
Practical Implications

Purpose This paper aims to develop a parsimonious and innovative model that captures the dynamics of new product diffusion in the recent high-technology markets and thus assist both academicians and practitioners who are eager to understand the diffusion phenomena. Accordingly, this study develops a novel diffusion model to forecast the demand by centering on the dynamic state of the product’s adoption rate. The proposed study also integrates the consumer’s psychological point of view on price change and goodwill of the innovation in the diffusion process. Design/methodology/approach In this study, a two-dimensional distribution function has been derived using Cobb–Douglas’s production function to combine the effect of price change and continuation time (goodwill) of the technology in the market. Focused on the realistic scenario of sales growth, the model also assimilates the time-to-time variation in the adoption rate (hazard rate) of the innovation owing to companies changing marketing and pricing strategies. The time-instance upon which the adoption rate alters is termed as change-point. Findings For validation purpose, the developed model is fitted on the actual sales and price data set of dynamic random access memory (DRAM) semiconductors, liquid crystal display (LCD) monitors and room air-conditioners using non-linear least squares estimation procedure. The results indicate that the proposed model has better forecasting efficiency than the conventional diffusion models. Research limitations/implications The developed model is intrinsically restricted to a single generation diffusion process. However, technological innovations appear in generations. Therefore, this study also yields additional plausible directions for future analysis by extending the diffusion process in a multi-generational environment. Practical implications This study aims to assist marketing managers in determining the long-term performance of the technology innovation and examine the influence of fluctuating price on product demand. Besides, it also incorporates the dynamic tendency of adoption rate in modeling the diffusion process of technological innovations. This will support the managers in understanding the practical implications of different marketing and promotional strategies on the adoption rate. Originality/value This is the first attempt to study the value-based diffusion model that includes key interactions between goodwill of the innovation, price dynamics and change-point for anticipating the sales behavior of technological products.

Effect of asymmetric structural characteristics of multi-hole marine diesel injectors on internal cavitation patterns and flow characteristics: A numerical study

Fuel ◽  
2021 ◽  
Vol 283 ◽  
pp. 119324
Author(s):  
Wei Guan ◽  
Zhixia He ◽  
Liang Zhang ◽  
Ahmed I. EL-Seesy ◽  
Liming Wen ◽  
...  
Keyword(s):  
Numerical Study ◽  
Structural Characteristics ◽  
Flow Characteristics ◽  
Marine Diesel

Stress-dependent anisotropy index of strength and deformability of jointed rock mass: insights from a numerical study

2019 ◽  
Vol 78 (8) ◽  
pp. 5905-5917 ◽  
Author(s):  
Na Wu ◽  
Zheng-zhao Liang ◽  
Ying-chun Li ◽  
Hong Li ◽  
Wan-run Li ◽  
...  
Keyword(s):  
Rock Mass ◽  
Numerical Study ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Anisotropy Index ◽  
Stress Dependent

Spatial Diffusion Model Analysis and Trend of Shizuishan City

2012 ◽  
Vol 174-177 ◽  
pp. 2370-2373
Author(s):  
Bin Feng ◽  
Xiao Jian Chen
Keyword(s):  
Diffusion Process ◽  
Diffusion Model ◽  
Urban Space ◽  
Urban Expansion ◽  
Spatial Diffusion ◽  
Spatial Expansion ◽  
Weighted Distance ◽  
Zero Resistance ◽  
Coordination Development ◽  
Development Tendency

The urban expansion direction and mode of Shizuishan City is addressed based on GIS and improved spatial diffusion model-replacing the spatial straight distance with cost weighted distance. This paper divides its spatial expansion into four cases: zero resistance, resistance, incomplete barrier and isolation. The diffusion model of urban space in terms of the new understanding of the resistance barrier in the spatial diffusion process is discussed. Then, this paper puts forward new trends of spatial development. The results reveal that Dawukou city area and Pingluo city, and Wuhai city and Huinong district form the coordination development tendency.

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