scholarly journals Evaluation and Application of Surrounding Rock Stability Based on the Improved Weighting Multidimensional Cloud Model

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jing Long Li ◽  
Chao Yuan ◽  
Bo Zhang ◽  
Bin Sui

Aiming at the uncertainty in the existing tunnel surrounding rock stability evaluation methods and the inability to make scientific explanations in the process of determining the weights of multiple evaluation indicators, this paper combines subjective weighting based on the nonlinear characteristics of the surrounding rock stability evaluation criteria. Based on the advantages of the method AHP and the objective weighting method CRITIC, a comprehensive weighting method with multiple evaluation indicators is proposed, which is integrated with the multidimensional normal cloud model to establish a surrounding rock stability evaluation method for the improved weighted multidimensional cloud model and accurately obtain the safety level of tunnel surrounding rock construction. The multidimensional cloud model based on improved weighting not only solves the two major problems of randomness and ambiguity in surrounding rock stability evaluation but also fully considers the influence of the information contained in each evaluation factor on the results. The surrounding rock stability evaluation method in this paper is applied to the tunnel construction of the Beijing-Shanghai Expressway and Jinan Expressway connecting line construction project, and the evaluation results have a scientific guiding role for construction risk control.

2012 ◽  
Vol 594-597 ◽  
pp. 339-342
Author(s):  
Suo Juan Zhang ◽  
Guo Qing Qiu ◽  
Wen Bin Xie ◽  
Xiu Li Qi ◽  
Zhi Guang Ao ◽  
...  

Combined with the research of the stability grade of surrounding rock, this paper put forward into the extension method on surrounding rock stability around underground engineerings with extension theory. The extension method was improved the value of the limited field, the correlation function and weights coefficients to establish the stability evaluation method. The method was successfully applied into the underground engineering case, which has provided scientific reference for design and construction of underground engineerings.


2018 ◽  
Vol 175 ◽  
pp. 04016
Author(s):  
NIU Yan ◽  
Ji Yafei ◽  
Wang Zhao

Tunnel excavation will lead to the immediate surrounding rock unloading caused by the surrounding rock stress release, the stability of the surrounding rock have a certain impact. In this paper, finite element software ANSYS and finite difference software FLAC3D are used to simulate the excavation and lining process of circular tunnel. The influence of excavation on the rock stability around circular tunnel is analyzed, and the effect of applying lining on the stability of surrounding rock is analyzed. Evaluation criteria selection hole displacement, stress and plastic area of three factors.


2020 ◽  
Vol 10 (22) ◽  
pp. 8245
Author(s):  
Kyuhwan Oh ◽  
Jaeik Lee ◽  
Junhyeok Choi ◽  
Yonggul Park

Countries such as Korea adopt design codes, evaluation criteria and specifications from standards originating abroad; this leads to a lack of distinction of the separate applications of dynamic stability evaluation parameters between various track structures of different track moduli. This paper discusses the applicability of the dynamic stability evaluation method of railway track structures by assessing 10 different types of railway track sections of a newly constructed railway operation line (5 ballasted and 5 concrete type track structures) by field instrumentation testing. Parameters of track support stiffness (TSS), wheel load fluctuation, derailment coefficient, and rail displacement are measured. The respective results are first compared to the standard criteria (design specification) and comparisons between the different track types are presented as ratios. Findings show that while all of the tracks satisfy the design specification requirements, each track type measurement result varies by a noticeable degree, particularly when comparing between concrete and ballast type track structures. Results of the study demonstrate that using the same dynamic stability evaluation criteria can lead to an incorrect assessment of the track performance evaluation of track structure, and a separate evaluation parameter for ballasted and concrete track structures is required.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yingchao Wang ◽  
Ning Zhao ◽  
Hongwen Jing ◽  
Bo Meng ◽  
Xin Yin

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Chao Min ◽  
Guoquan Wen ◽  
Binrui Li ◽  
Xiaochan Zhao

Taking the development plans of an offshore oilfield as an example, a new comprehensive evaluation method, the improved Grey Clustering Analysis based on the cloud model (GCAC), is presented in this paper, which takes the ambiguity, randomness, and uncertainty of data into account and overcomes the limits of the general methods, such as subjective prejudice and objective randomness. GCAC converts the data of the oilfield development plans into a cloud, which considers the data of fuzziness, randomness, and the relationship between them. The grey membership degree of each development plan is calculated by this cloud model and an improved grey whitened function is presented in this paper. Then the plans are reordered by their grey membership degrees. In order to make more reasonable consideration of the artificial or unartificial uncertainties, GCAC combines the Grey Entropy Weighting method, Analytical Hierarchy Process (AHP), and Expert Assessment method to determine the weights of each level of indexes, which makes the weights more reasonable and reduces the randomness and the fuzziness of data. GCAC can help obtain a better comparison between the development plans. The reliability of this method is verified by the calculation results.


2011 ◽  
Vol 261-263 ◽  
pp. 1567-1572
Author(s):  
Nian Peng ◽  
Lin Kun Gan

With the increase of traffic volume, the enlarging tunnel span and the decreasing of surrounding rock integrity, the level of surrounding rock will be lower. This article proposed the calculating method of relative integrity index based on the concept of relative integrity of surrounding rock and established the Fuzzy Comprehensive Evaluation Method for rock classification by analyzing the impact of tunnel span enlargement upon rock stability. It also specified the determination factors, discussed the selection of weight indexes and proposed methods of establishing the qualitative and quantitative subordinate degrees. Based on practices of the expressways of Fuzhou, Xiamen and Zhangzhou, this article made fuzzy comprehensive evaluation of rock classification and fully analyzed the results of the evaluation. Results showed that with the enlargement of tunnel span, levels of surrounding rock would lower accordingly, and that the worse surrounding rock was, the more it would lower.


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