nowadays, tunneling in urban areas is a common activity for a variety of transportations such as subways, water supply, lifelines andsewers that may require blast operations. the characteristics of stress waves of the blast are quite different from earthquake waves. the blast waves are usually of high frequency content, short duration, equality of amplitudes in horizontal and vertical direction...

impact pile driving is a multi-component problem which is associated to multi-directional ground vibrations. at first, vibration is transferred from the hammer to the pile and then to the common interface of pile and soil. this is then transferred to the environment and has great impact on the adjacent structures, causing disturbance to residents and also damage to the buildings. it is of high ...

nowadays, tunneling in urban areas is a common activity for a variety of transportations such as subways, water supply, lifelines andsewers that may require blast operations. the characteristics of stress waves of the blast are quite different from earthquake waves. the blast waves are usually of high frequency content, short duration, equality of amplitudes in horizontal and vertical direction...

Geckos have the extraordinary ability to prevent their sticky feet from fouling while running on dusty walls and ceilings. Understanding gecko adhesion and self-cleaning mechanisms is essential for elucidating animal behaviours and rationally designing gecko-inspired devices. Here we report a unique self-cleaning mechanism possessed by the nano-pads of gecko spatulae. The difference between the...

we have applied the method of integration of the heisenberg equation of motion proposed by bender and dunne, and m. kamella and m. razavy to the potential v(q) = v q - µ q with linear and nonlinear dissipation. we concentrate our calculations on the evolution of basis set of weyl ordered operators and calculate the mean position , velocity , the commutation relation [q, p], and the energy of pa...

The paper considers receiving acoustic horns designed for particle velocity amplification and suitable for use in vector sensing applications. Unlike conventional horns, designed for acoustic pressure amplification, acoustic velocity horns (AVHs) deliver significant velocity amplification even when the overall size of the horn is much less than an acoustic wavelength. An AVH requires an open-en...

shear wave velocity is a basic engineering tool required to define dynamic properties of soils. in many instances it may be preferable to determine vs indirectly by common in-situ tests, such as the standard penetration test. many empirical correlations based on the standard penetration test are broadly classified as regression techniques. however, no rigorous procedure has been published for c...

ground vibrations caused by blasting are undesirable results in the mining industry and can cause serious damage to the nearby buildings and facilities; therefore, controlling such vibrations has an important role in reducing the environmental damaging effects. controlling vibration caused by blasting can be achieved once peak particle velocity (ppv) is predicted. in this paper, the values of p...

a linear superposition method was used for modeling the time history of the production blast vibrations and optimizing the blast sequence to reduce vibration levels in sar-cheshmeh copper mine, kerman, iran. a single-hole blast for modeling and two double-hole blasts with time delays of 25 and 65 ms between two holes for modeling validation were carried out. the generated vibrations were measur...

in the current study, the immersed boundary – non-newtonian lattice boltzmann method is developed for simulation of forces act on a particle and also for computation of the particle velocity in vicinity of non-newtonian fluids. in this research, the effect of extra force due to accelerated mass is also considered in non-newtonian particle motion equations. two applied problems of power-law non-...