Mechanical and Chemical Reinforcements for the Installation of Underground Utilities to Mitigate Underground Cavity

2017 ◽  
Vol 17 (3) ◽  
pp. 257-268 ◽  
Author(s):  
Heetae Yoo ◽  
◽  
Jeongho Oh ◽  
2019 ◽  
Vol 107 ◽  
pp. 102893 ◽  
Author(s):  
Waqas Arshad Tanoli ◽  
Abubakar Sharafat ◽  
Jaemin Park ◽  
Jong Won Seo

Author(s):  
Chenyang Zhao ◽  
Qiang Zhang ◽  
Mingfeng Lei ◽  
Yintao Song ◽  
Guodong Liang ◽  
...  

2021 ◽  
Author(s):  
Felix M. Schneider ◽  
Petr Kolínský ◽  
Götz Bokelmann

<p>We study finite-frequency effects that arise in cavity detection. The task comes along with the Onsite-Inspection part for the Comprehensive Nuclear Test Ban Treaty (CTBT), where the remnants of a potential nuclear test need to be identified. In such nuclear tests, there is preexisting knowledge about the depths at which nuclear tests may take place, and also about sizes that such cavities can attain. The task of cavity detection has consistently been a difficult one in the past, which is surprising, since a cavity represents one of the strongest seismic anomalies one can ever have in the subsurface. A conclusion of this study is that considering finite-frequency effects are rather promising for cavity detection, and that it is worthwhile to take them into account. We utilize an analytical approach for the forward problem of the a seismic wave interacting with a underground cavity in order to develop an inversion routine that finds and detects an underground cavity utilizing the transmitted wave-field.</p><p> </p>


Author(s):  
Ghazi Saad A Elawi ◽  
Mohammed Algahtany ◽  
Dean Kashiwagi ◽  
Kenneth Sullivan

Delays are a major cause for concern in the construction industry in Saudi Arabia. This paper identifies the main causes of delay in infrastructure projects in Mecca, Saudi Arabia, and compares these with projects around the country and other Gulf countries. Data was obtained from 49 infrastructure projects undertaken by the owner and were analyzed quantitatively to understand the causes and severity of delay. 10 risk factors were identified and were grouped into four categories. Average delay in infrastructure projects in Mecca was found to be 39% of the estimated projects schedules. The most severe cause of delay was found to be the land acquisition factor. This highlights the critical land ownership and acquisition issues that are prevailing in the city. Additionally, other factors that contribute to delay include contractors’ lack of expertise, haphazard underground utilities (line services), and re-designing. It is concluded that the majority of project delays were caused from the owner’s side as compared to contractors, consultants, and other project’s stakeholders. This finding matched with the research findings of the Gulf Countries Construction (GCC) industry’s literature. This study fills an important practice and research gap for improving the efficiency in delivering infrastructure projects in the holy city of Mecca and Gulf countries at large.


2019 ◽  
Vol 218 (3) ◽  
pp. 1903-1918 ◽  
Author(s):  
C Filippi ◽  
D Leparoux ◽  
G Grandjean ◽  
A Bitri ◽  
Ph Côte

2018 ◽  
Vol 150 ◽  
pp. 52-66 ◽  
Author(s):  
Muhammad Bilal ◽  
Wasiq Khan ◽  
Jennifer Muggleton ◽  
Emiliano Rustighi ◽  
Hugo Jenks ◽  
...  

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