Classification model for surrounding rock based on the PCA-ideal point method: an engineering application

2018 ◽  
Vol 78 (5) ◽  
pp. 3627-3635 ◽  
Author(s):  
Yiguo Xue ◽  
Zhiqiang Li ◽  
Daohong Qiu ◽  
Lewen Zhang ◽  
Ying Zhao ◽  
...  
Keyword(s):  
Ideal Point ◽  
Engineering Application ◽  
Surrounding Rock ◽  
Point Method ◽  
Classification Model

scholarly journals A Novel Model of the Ideal Point Method Coupled with Objective and Subjective Weighting Method for Evaluation of Surrounding Rock Stability

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yingchao Wang ◽  
Ning Zhao ◽  
Hongwen Jing ◽  
Bo Meng ◽  
Xin Yin
Keyword(s):  
Present Model ◽  
Ideal Point ◽  
Surrounding Rock ◽  
Point Method ◽  
Good Prospect ◽  
Weighting Method ◽  
Rock Classification ◽  
Rock Stability ◽  
The Ideal

The classification of surrounding rock stability is the critical problem in tunneling engineering. In order to decrease engineering disasters, the surrounding rock stability should be accurately evaluated. The ideal point method is applied to the classification of surrounding rock stability. Considering the complexity of surrounding rock classification, some factors such as rock uniaxial compressive strengthen, integrality coefficient of rock mass, the angle between tunnel axis and the main joint, joints condition, and seepage measurement of groundwater are selected as evaluation indices. The weight coefficients of these evaluation indices are determined by the objective and subjective weighting method, consisting with the delphi method and the information entropy theory. The objective and subjective weighting method is exact and reliable to determine the weights of evaluation indices, considering not only the expert’s experiences, but also objectivity of the field test data. A new composite model is established for evaluating the surrounding rock stability based on the ideal point method and the objective and subjective weighting method. The present model is applied to Beigu mountain tunnel in Jiangsu province, China. The result is in good agreement with practical situation of surrounding rock, which proves that the ideal point method used to classify the surrounding rock in tunnels is reasonable and effective. The present model is simple and has very strong operability, which possesses a good prospect of engineering application.

scholarly journals Intelligent Classification Model of Surrounding Rock of Tunnel using Drilling and Blasting Method

2020 ◽  
Author(s):  
Mingnian Wang ◽  
Siguang Zhao ◽  
Jianjun Tong ◽  
Zhilong Wang ◽  
Meng Yao ◽  
...  
Keyword(s):  
Surrounding Rock ◽  
Classification Model ◽  
Blasting Method

scholarly journals Study of the Stability Control of the Rock Surrounding Double-Key Strata Recovery Roadways in Shallow Seams

2019 ◽  
Vol 2019 ◽  
pp. 1-21 ◽  
Author(s):  
Cheng Zhu ◽  
Yong Yuan ◽  
Zhongshun Chen ◽  
Zhiheng Liu ◽  
Chaofeng Yuan
Keyword(s):  
Engineering Application ◽  
Stability Control ◽  
Surrounding Rock ◽  
Control Effect ◽  
Pressure Relief ◽  
Support Design ◽  
Key Strata ◽  
Fracture Development ◽  
Surrounding Rock Control ◽  
The Stability

The stability control of the rock surrounding recovery roadways guarantees the safety of the extraction of equipment. Roof falling and support crushing are prone to occur in double-key strata (DKS) faces in shallow seams during the extraction of equipment. Therefore, this paper focuses on the stability control of the rock surrounding DKS recovery roadways by combining field observations, theoretical analysis, and numerical simulations. First, pressure relief technology, which can effectively release the accumulated rock pressure in the roof, is introduced according to the periodic weighting characteristics of DKS roofs. A reasonable application scope and the applicable conditions for pressure relief technology are given. Considering the influence of the eroded area on the roof structure, two roof mechanics models of DKS are established. The calculation results show that the yield load of the support in the eroded area is low. A scheme for strengthening the support with individual hydraulic props is proposed, and then, the support design of the recovery roadway is improved based on the time effects of fracture development. The width of the recovery roadway and supporting parameters is redesigned according to engineering experience. Finally, constitutive models of the support and compacted rock mass in the gob are developed with FLAC3D software to simulate the failure characteristics of the surrounding rock during pressure relief and equipment extraction. The surrounding rock control effects of two support designs and three extraction schemes are comprehensively evaluated. The results show that the surrounding rock control effect of Scheme 1, which combines improved support design and the bidirectional extraction of equipment, is the best. Engineering application results show that Scheme 1 realizes the safe extraction of equipment. The research results can provide a reference and experience for use in the stability control of rock surrounding recovery roadways in shallow seams.

Optimierung der Revitalisierungskosten von Bestandsobjekten

Bauingenieur ◽  
2020 ◽  
Vol 95 (11) ◽  
pp. A 28-A 32
Author(s):  
Dominik Krawczyk ◽  
Pawel Nowak
Keyword(s):  
Ideal Point ◽  
Point Method

Der Artikel beschreibt das Vorgehen bei der Bewertung von fünf möglichen Varianten zur Senkung der Baukosten, die im Zusammenhang mit der Revitalisierung und Rekonstruktion eines historischen Gebäudes als Einkaufszentrum betrachtet wurden. Diese Varianten wurden nach dem Kriterium Baukosten als einem quantitativen Kriterium sowie nach den qualitativen Kriterien Visueller Eindruck, Funktionalität sowie Planungsflexibilität bewertet. Aufgrund der komplizierten qualitativen Bewertungen durch Experten wurde eine der Methoden der multikriteriellen Optimierung eingesetzt, welche nach Ansicht der Autoren im Rahmen von Entscheidungsprozessen in Bauinvestitionen selten zur Anwendung kommen. Im vorliegenden Fall wurde die Ideal Point Method eingesetzt.

scholarly journals Primary Investigation on Equivalent Anchoring Method of Jointed Rock Mass Tunnel and Its Engineering Application

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Min Gao ◽  
Shanpo Jia
Keyword(s):  
Rock Mass ◽  
Three Dimensional ◽  
Engineering Application ◽  
Friction Angle ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Surrounding Rock ◽  
Rock Masses ◽  
Reinforcement Effect ◽  
Rock Bolts

Rock bolts, one of the main support structures of the tunnel, can improve the stress state and mechanical properties of the surrounding rocks. The rock bolts are simulated by bar or beam elements in present numerical calculations for most 2D tunnel models. However, the methods of simulating rock bolt in three-dimensional models are rarely studied. Moreover, there are too many rock bolts in the long-span tunnel, which are hardly applied in the 3D numerical model. Therefore, an equivalent anchoring method for bolted rock masses needs to be further investigated. First, the jointed material model is modified to simulate the anisotropic properties of surrounding rock masses. Then, based on the theoretical analysis of rock bolts in reinforcing mechanical properties of the surrounding rock masses, the equivalent anchoring method of the jointed rock mass tunnel is numerically studied. The equivalent anchoring method is applied to the stability analysis of a diversion tunnel in Western China. From the calculation results, it could be found that the reinforcement effect of rock bolts could be equivalently simulated by increasing the mechanical parameter value of surrounding rocks. For the jointed rock mass tunnel, the cohesion and internal friction angle of the surrounding rocks are improved as 1.7 times and 1.2 times of the initial value, which can simulate the reinforcement effect of rock bolts. Comparing with analytical results, the improved internal friction angle is nearly consistent with analytical result. The reinforcement effect of rock bolts is simulated obviously when the mechanical parameters of surrounding rocks are increased simultaneously. The engineering application shows that the equivalent anchoring method can reasonably simulate the effect of rock bolts, which can provide reference for stability analysis of three-dimensional tunnel simulations.

Research on Surrounding Rock Stability by Ideal Point-Rough Set Efficacy Coefficient Method

2013 ◽  
Vol 353-356 ◽  
pp. 415-420 ◽  
Author(s):  
Guo Ren Lu ◽  
Le Wen Zhang ◽  
Dao Hong Qiu ◽  
Xiao Feng
Keyword(s):  
Stability Analysis ◽  
Rough Set ◽  
Ideal Point ◽  
Surrounding Rock ◽  
Ideal Solution ◽  
Rock Stability ◽  
The Stability ◽  
Efficacy Coefficient Method ◽  
Coefficient Method ◽  
The Ideal

The ideal point method is a kind of multiple-goal decision analysis method, the basic idea is to construct the ideal and anti-ideal solution of multi attribute problem, with degree that near ideal solution and away from the anti-ideal solution as the basis to judge each evaluation object. Based on the basic principle of ideal point method, and comprehensive consideration of the actual geological conditions of Qingdao metro, we selected rock compressive strength, integrity coefficient, structure surface behavior, groundwater and softening coefficient as the evaluation factors of surrounding rock stability, and used the rough set theory to determine the index weight. At last, established the evaluate model for the surrounding rock stability of metro based on the rough set efficacy coefficient method. The research show that the stability analysis results are consistent with the actual excavation, so using rough set efficacy coefficient method to analysis surrounding rock stability of Qingdao Metro is feasible, which provides a new idea for the stability analysis of surrounding rock.

scholarly journals Developing Common Set of Weights with Considering Nondiscretionary Inputs and Using Ideal Point Method

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Reza Kiani Mavi ◽  
Sajad Kazemi ◽  
Jay M. Jahangiri
Keyword(s):  
Decision Making ◽  
Ideal Point ◽  
Main Idea ◽  
Efficiency Score ◽  
Point Method ◽  
Bank Branches ◽  
Proposed Model ◽  
Decision Making Unit ◽  
Common Set Of Weights ◽  
Nondiscretionary Inputs

Data envelopment analysis (DEA) is used to evaluate the performance of decision making units (DMUs) with multiple inputs and outputs in a homogeneous group. In this way, the acquired relative efficiency score for each decision making unit lies between zero and one where a number of them may have an equal efficiency score of one. DEA successfully divides them into two categories of efficient DMUs and inefficient DMUs. A ranking for inefficient DMUs is given but DEA does not provide further information about the efficient DMUs. One of the popular methods for evaluating and ranking DMUs is the common set of weights (CSW) method. We generate a CSW model with considering nondiscretionary inputs that are beyond the control of DMUs and using ideal point method. The main idea of this approach is to minimize the distance between the evaluated decision making unit and the ideal decision making unit (ideal point). Using an empirical example we put our proposed model to test by applying it to the data of some 20 bank branches and rank their efficient units.

scholarly journals A Modified 3D-QSAR Model Based on Ideal Point Method and Its Application in the Molecular Modification of Plasticizers with Flame Retardancy and Eco-Friendliness

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1942
Author(s):  
Haigang Zhang ◽  
Chengji Zhao ◽  
Hui Na
Keyword(s):  
Flame Retardancy ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Ideal Point ◽  
Three Dimensional ◽  
3D Qsar ◽  
Qsar Model ◽  
Quantitative Structure Activity Relationship ◽  
Point Method ◽  
Contour Maps

The addition of plasticizers makes plastics flammable, and thus, poses a potential risk to the environment. In previous researches, plasticizers with flame retardancy had been synthesized, but their eco-friendliness had not been tested or described. Thus, in this paper, eco-friendliness plasticizers with flame retardancy were designed based on phthalic acid esters (PAEs), which are known as common plasticizers and major plastic additives. For a comprehensive analysis, such as flammability, biotoxicity, and enrichment effects, 17 PAEs’ comprehensive evaluation values were calculated based on the ideal point method. Further, a multi-effect three-dimensional quantitative structure-activity relationship (3D-QSAR) model of PAEs’ flammability, biotoxicity and enrichment effects was constructed. Thus, 18 dimethyl phthalate (DMP) derivatives and 20 diallyl phthalate (DAP) derivatives were designed based on three-dimensional contour maps. Through evaluation of eco-friendliness and flammability, six eco-friendly PAE derivatives with flame retardancy were screened out. Based on contour maps analysis, it was confirmed that the introduction of large groups and hydrophobic groups was beneficial to the simultaneous improvement of PAEs’ comprehensive effects, and multiple effects. In addition, the group properties were correlated significantly with improved degrees of the comprehensive effects of corresponding PAE derivatives, confirming the feasibility of the comprehensive evaluation method and modified scheme.

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