In-situ stress measurement of molybdenum/silicon multilayers and low-stress multilayers for extreme-ultraviolet lithography

2001 ◽  
Author(s):  
Masayuki Shiraishi ◽  
Wakana Ishiyama ◽  
Noriaki Kandaka ◽  
Tetsuya Oshino ◽  
Katsuhiko Murakami
Keyword(s):  
Extreme Ultraviolet ◽  
Stress Measurement ◽  
In Situ Stress ◽  
Extreme Ultraviolet Lithography ◽  
Ultraviolet Lithography ◽  
In Situ Stress Measurement

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.

Deformation Memory Effect Identification Using Fractal Dimension in the Stress Region above Crack Initiation Threshold

2011 ◽  
Vol 90-93 ◽  
pp. 2332-2338
Author(s):  
Hai Jun Wang ◽  
Xu Hua Ren ◽  
Ji Xun Zhang
Keyword(s):  
Fractal Dimension ◽  
Memory Effect ◽  
Stress Measurement ◽  
Numerical Models ◽  
Strain Curve ◽  
In Situ Stress ◽  
Identification Methods ◽  
Stress Region ◽  
In Situ Stress Measurement

Deformation memory effect (DME) is one of the rock memory effects. One important application of the DME is to determine the in situ stress. The in situ stress measurement methods based on the DME are commercial and permit large number of measurements. Application of DME needs the reliable and effective identification methods to detect the DME. However, the existing identification methods are insufficient and not distinct. In this paper, a new method based on fractal dimension was proposed. It takes advantage of the increase of the irregularity of the stress-strain curve after the previous maximum stress attained. Numerical models for the sandstone and granite were developed based on the contact bond model in PFC2D. Fractal dimension method was employed to detect the DME for two types of the rock. The results demonstrate that the fractal dimension method is effective and reliable in the identification of DME in rock.

Rock Overstressing in Deep Tunnel Excavation of Pahang-Selangor Raw Water Transfer Project

2015 ◽  
Vol 802 ◽  
pp. 16-21 ◽  
Author(s):  
Romziah Azit ◽  
Mohd Ashraf Mohamad Ismail ◽  
Sharifah Farah Fariza Syed Zainal ◽  
Norzani Mahmood
Keyword(s):  
Rock Strength ◽  
Stress Measurement ◽  
In Situ Stress ◽  
Water Transfer ◽  
Stress Factors ◽  
Raw Water ◽  
Tunnel Excavation ◽  
In Situ Stress Measurement ◽  
Assessment Approach

Tunneling under high overburden and in-situ stress may cause tunnel instability because of rock overstressing. Evaluating overstressing in deep hard rocks is crucial to minimize excavation risks. The excavation of the Pahang-Selangor Raw Water Transfer Tunnel is evaluated in this study. A potential overstressing problem is expected at a tunnel depth more than 500 m. Therefore, the possibility of rock overstressing is assessed based on the evaluations of in-situ stress measurement, rock strength, and actual observations during the tunnel excavation. An analytical method is used to analyze the behavior of the tunnel under high overburden stress based on rock strength and tangential stress factors. The empirical assessment approach to the observation of actual overstressing appeared to be valid for the prediction of overstressing. These approaches facilitate the reasonable prediction of tunnel behavior under different rock conditions, support systems, and overburden stresses, which serve as useful tools in the observational design and construction method of long and deep tunnels.

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