Study on Refined Back-Analysis Method for Stress Field Based on In Situ and Disturbed Stresses

2021 ◽  
Vol 21 (8) ◽  
pp. 04021141
Author(s):  
Changyu Jin ◽  
Yu Lu ◽  
Tao Han ◽  
Tianyu Chen ◽  
Jianxin Cui ◽  
...  
Keyword(s):  
Stress Field ◽  
Back Analysis ◽  
Analysis Method

Back Analysis Methods in Geotechnical Engineering

2014 ◽  
Vol 1020 ◽  
pp. 423-428 ◽  
Author(s):  
Eva Hrubesova ◽  
Marek Mohyla
Keyword(s):  
Rock Mass ◽  
Geotechnical Engineering ◽  
Back Analysis ◽  
Rheological Parameters ◽  
Analysis Method ◽  
Direct Optimization ◽  
Initial Stress State ◽  
Analytical Functions ◽  
Is Evaluation

The paper deals with the back analysis method in geotechnical engineering, that goal is evaluation the more objective and reliable parameters of the rock mass on the basis of in-situ measurements. Stress, deformational, strength and rheological parameters of the rock mass are usually determined by some inaccuracies and errors arising from the complexity and variability of the rock mass. This higher or lower degree of imprecision is reflected in the reliability of the mathematical modelling results. The paper presents the utilization of direct optimization back analysis method, based on the theory of analytical functions of complex variable and Kolosov-Muschelischvili relations, to the evaluation of initial stress state inside the rock massif.

scholarly journals Finite Element Optimised Back Analysis of In Situ Stress Field and Stability Analysis of Shaft Wall in the Underground Gas Storage

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Yifei Yan ◽  
Bing Shao ◽  
Jianguo Xu ◽  
Xiangzhen Yan
Keyword(s):  
Finite Element ◽  
Stress Field ◽  
Geometric Model ◽  
Back Analysis ◽  
Gas Storage ◽  
In Situ Stress ◽  
Underground Gas Storage ◽  
Measured Stress ◽  
In Situ Stress Field

A novel optimised back analysis method is proposed in this paper. The in situ stress field of an underground gas storage (UGS) reservoir in a Turkey salt cavern is analysed by the basic theory of elastic mechanics. A finite element method is implemented to optimise and approximate the objective function by systematically adjusting boundary loads. Optimising calculation is performed based on a novel method to reduce the error between measurement and calculation as much as possible. Compared with common back analysis methods such as regression method, the method proposed can further improve the calculation precision. By constructing a large circular geometric model, the effect of stress concentration is eliminated and a minimum difference between computed and measured stress can be guaranteed in the rectangular objective region. The efficiency of the proposed method is investigated and confirmed by its capability on restoring in situ stress field, which agrees well with experimental results. The characteristics of stress distribution of chosen UGS wells are obtained based on the back analysis results and by applying the corresponding fracture criterion, the shaft walls are proven safe.

Back Analysis for Rock Mechanical Parameters and Calculation of Ground Stress Based on GA-FLAC3D

2012 ◽  
Vol 462 ◽  
pp. 468-473
Author(s):  
Ze Zhang ◽  
Tong Bin Zhao ◽  
Yun Liang Tan ◽  
Chong Guang Zhang
Keyword(s):  
Genetic Algorithm ◽  
Deep Level ◽  
Back Analysis ◽  
In Situ Stress ◽  
Mechanical Parameters ◽  
Analysis Method ◽  
Stress Relieving ◽  
Ground Stress ◽  
Rock Mechanical Parameters

In order to obtain the stress distribution in deep level of Datai mine, a nonlinear back analysis method for rock mechanical parameters was proposed by combining genetic algorithm and FLAC3D (GA-FLAC3D). First the hollow inclusion stress gauge (stress relieving method) was used to complete the measurement of local in-situ stress; and then the rock mechanical parameters were obtained by using back analysis; at last the ground stress in deep level was obtained. The results showed, this method is quick in calculation, and has global convergence. The convergence accuracy of normal stress is about 90%.

Numerical Analysis on Minimal Safe Distance between Two Opposite Excavation Faces of Deep-Buried Tunnel

2013 ◽  
Vol 353-356 ◽  
pp. 1315-1320
Author(s):  
Wen Tao Chen ◽  
Yi Huan ◽  
Peng Xian Fan
Keyword(s):  
Stress Field ◽  
Influence Factors ◽  
Back Analysis ◽  
Safe Distance ◽  
Transient Stress ◽  
Initial Stress Field ◽  
Rock Pillar ◽  
Deep Rock ◽  
Rock Mechanical Properties

When the distance between two opposite excavation face is too small, the explosive load of one excavation face may causes rock failure of the other excavation face and result in engineering accidents. In this paper, the dynamic response of rock pillar between two opposite excavation faces during one explosive excavation cycle is investigated. An aftereffect function is adopted to reflect the viscoelastic properties of deep rock mass, and the explicit difference scheme of stress field is derived and then implemented by Matlab programs. The transient stress field of rock pillar is computed by coupling the initial stress field and the explosive waves. The analogies between the minimal safe distance and those influence factors such as explosive excavation load, rock mechanical properties, in-situ stresses, are fulfilled by this method. The back analysis results of a real case indicate that the results of presented method agree well with the actual situation.

An automatic analysis method for in situ hybridization using high-resolution image analysis

1989 ◽  
Vol 281 (5) ◽  
pp. 336-341 ◽  
Author(s):  
W. Stolz ◽  
K. Scharffetter ◽  
W. Abmayr ◽  
W. K�ditz ◽  
T. Krieg
Keyword(s):  
Image Analysis ◽  
In Situ Hybridization ◽  
High Resolution ◽  
Automatic Analysis ◽  
Analysis Method ◽  
Resolution Image ◽  
High Resolution Image

In Situ Stress Measurement and Inversion in Deep Roadway

2013 ◽  
Vol 734-737 ◽  
pp. 759-763 ◽  
Author(s):  
Yong Li ◽  
Yun Yi Zhang ◽  
Ren Jie Gao ◽  
Shuai Tao Xie
Keyword(s):  
Field Measurement ◽  
Stress Measurement ◽  
Measurement Data ◽  
Back Analysis ◽  
In Situ Stress ◽  
Deep Mine ◽  
Accuracy Requirement ◽  
Initial Stress Field ◽  
In Situ Stress Measurement

Jixi mine area is one of the early mined areas in China and it's a typical deep mine. Because of large deformation of underground roadway and dynamic disasters occurred frequently in this mine, five measurement points of in-situ stress in this mine was measured and then analyzed with inversion. Based on these in-situ stress measurement data, numerical model of 3D in-situ stress back analysis was established. According to different stress fields, related analytical samples of neural network were given with FLAC program. Through the determination of hidden layers, hidden nodes and the setting of parameters, the network was optimized and trained. Then according to field measurement of in-situ stress, back analysis of initial stress field was conducted. Compared with field measurement, with accuracy requirement satisfied, it shows that the in-situ stress of rock mass obtained is basically reasonable. Meanwhile, it proves that the measurement of in-situ stress can provide deep mines with effective and rapid means, and also provide reliable data to optimization of deep roadway layout and supporting design.

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