Multiple seed blast vibration modeling for tunnel blasting in urban environments

AbstractIn tunnel blasting excavation, it is important to clarify the attenuation law of blast wave propagation and predict the blast vibration velocity effectively to ensure safe tunnel construction and protection design. The effects of the free surface area its quantity on the blast vibration velocity are considered, and free surface parameters are introduced to improve the existing blast vibration velocity prediction formula. Based on the Tianhuan railway Daqianshiling tunnel project, field blast vibration monitoring tests are performed to determine changes in the peak blasting vibration velocity based on the blast distance and free surface area. LS-DYNA is used to establish tunnel blasting excavation models under three operating conditions; subsequently, the attenuation law of blast vibration velocity and changes in the vibration response spectrum are analysed. Results show that the free surface area and number of free surfaces enable the blast vibration velocity to be predicted under various operating conditions: a smaller free surface area results in a narrower frequency band range, whereas more free surfaces result in a narrower frequency band range. The improved blast vibration velocity prediction formula is validated using field and numerical test data. It is indicated that the improved formula is applicable to various tunnelling conditions.

Download Full-text

The influence of natural and urban environments on attentional processing of emotional stimuli

PsycEXTRA Dataset ◽

10.1037/e522252014-234 ◽

2014 ◽

Author(s):

Chrono Nu ◽

Katie Mullin ◽

Hailey Edwards ◽

Kailey Kornhauser ◽

Russell Costa ◽

...

Keyword(s):

Urban Environments ◽

Emotional Stimuli ◽

Attentional Processing

Download Full-text

Minimetrò in Perugia as leverage for urban regeneration

TERRITORIO ◽

10.3280/tr2019-091015 ◽

2020 ◽

pp. 148-163

Author(s):

Luca Fondacci

Keyword(s):

Urban Regeneration ◽

Urban Environments ◽

Low Carbon ◽

Sustainable Mobility ◽

Field Surveys ◽

Peripheral Area ◽

Alternative Means ◽

Considerable Impact ◽

The City ◽

Historical Centre

In the 1970s, the fragile historical centre of the city of Perugia was a key area where the binomial of sustainable mobility and urban regeneration was developed and applied. At the turn of the xxi century, the low carbon automatic people-mover Minimetrò broadened that application from the city's historical centre to the outskirts, promoting the enhancement of several urban environments. This paper is the outcome of an investigation of original sources, field surveys and direct interviews, which addresses the Minimetrò as the backbone of a wide regeneration process which has had a considerable impact on the economic development of a peripheral area of the city which was previously devoid of any clear urban sense. The conclusion proposes some solutions to improve the nature of the Minimetrò as an experimental alternative means of transport.

Download Full-text