Results 151 to 160 of about 7,010,769 (298)

Motion planning and control of an installation robot for attitude adjustment of arc parts in underground shield tunneling

open access: yesDeep Underground Science and Engineering, EarlyView.
Inspired by spiders, the multilegged walk‐through assembling robot for arc parts achieves high‐precision synchronous control under heavy loads through dual‐layer hydraulic pose dynamics modeling and hierarchical pressure optimization, significantly enhancing shield tunneling assembly efficiency and precision.
Quan Xiao   +5 more
wiley   +1 more source

The demand for currency and the underground economy [PDF]

open access: yes
The underground economy in Canada has attracted increased attention over the past few years, yet there is no precise way to measure its size. Recent estimates vary between 4 per cent and 15 per cent of gross domestic product.
Thérèse Laflèche
core  

A rock brittleness index based on the postpeak energy release rate and damage surface characteristics for brittle hard rock

open access: yesDeep Underground Science and Engineering, EarlyView.
This study examines energy evolution in rock rupture via triaxial direct shear tests, exploring the impact of confining pressure and temperature on fracture surface randomness. A novel energy‐based brittleness index is proposed, validated experimentally, and compared with existing methods for reliability and accuracy.
Biao Wang   +5 more
wiley   +1 more source

Study on the composite fracture characteristics of filling and reinforcing cracked rock mass after high temperature damage

open access: yesDeep Underground Science and Engineering, EarlyView.
Cement infill shares compressive and shear stresses during loading, while interfacial friction hinders crack propagation and reduces stress concentration, improving the rock's load‐bearing capacity. Failure modes vary with crack inclination. Unfilled specimens show four modes.
Shihao Yuan   +4 more
wiley   +1 more source

Technical Development and Safety Risk Analysis of Urban Underground Engineering

open access: yes, 2018
With the rapid development of China's urban construction, the acceleration of urbanization and the rapid expansion of population, the effective development and utilization of urban underground space have attracted great attention.
Ye, Zhiqiang
core  

Modeling and experimental validation of bolt–grout bond–slip behavior for deep underground excavation support

open access: yesDeep Underground Science and Engineering, EarlyView.
A novel shear‐lag model, validated by pull‐out tests, incorporates a constant bond stress stage to predict the complete load–displacement response of grouted rock bolts, providing a new tool for optimizing anchorage length and material toughness in deep underground engineering. Abstract The stability of rock masses in deep underground excavations, such
Wenhui Bian   +6 more
wiley   +1 more source

Analytical stress solution framework for lined compressed air energy storage chambers and its application to safe burial depth determination and supporting effectiveness evaluation

open access: yesDeep Underground Science and Engineering, EarlyView.
An analytical framework delivers a closed‐form stress solution for lined compressed air energy storage chambers, enabling the determination of the minimum safe burial depth. The solution quantitatively evaluates lining support effectiveness, offering a reliable tool for chamber design and optimization.
Zeyuan Sun   +3 more
wiley   +1 more source

The size of the underground economy in Japan [PDF]

open access: yes
This paper empirically analyzes the size of the underground economy in Japan. The results show that (i) the size of the underground GDP peaked in the early 1990s but has been declining since; (ii) the underground economy reached its peak in around 1992 ...
Kanao, Koji, Hamori, Shigeyuki
core  

Mechanistic insights across curing regimes for enzymatic and biopolymer‐optimized reinforcement in rock masses

open access: yesDeep Underground Science and Engineering, EarlyView.
This study examines the effects of curing temperature on the mechanical behavior of underground rock masses treated with enzyme‐induced calcite precipitation (EICP) and an innovative biopolymer‐modified EICP (BP‐EICP). Abstract Biocementation is an innovative and sustainable technique for reinforcing weak and weathered rock masses in natural and ...
Mary C. Ngoma, Oladoyin Kolawole
wiley   +1 more source

The Deep Underground Science and Engineering Laboratory at Homestake

open access: yes, 2020
. The National Science Foundation and the international underground science community are well into establishing a world-class, multidisciplinary Deep Underground Science and Engineering Laboratory (DUSEL) at the former Homestake mine in Lead South ...
Kevin T Lesko
core  

Home - About - Disclaimer - Privacy